The Clinical Practice Guidelines for post-ERCP pancreatitis (PEP) 2023 provide updated recommendations for the prevention, diagnosis, and management of PEP. Endoscopic retrograde cholangiopancreatography (ERCP), a valuable procedure for diagnosing and treating pancreatobiliary diseases, can result in PEP as the most common adverse event. Since the first guidelines were published in 2015, advances in techniques and new research findings have necessitated this revision. The guidelines developed using the GRADE methodology target adult patients undergoing ERCP. They offer a comprehensive framework for clinicians to minimize the risk of PEP. For high-risk patients, endoscopic ultrasound before ERCP is recommended to avoid unnecessary procedures. The guidelines also discuss procedural and patient-related risk factors for PEP, highlighting that operator experience does not significantly affect PEP rates if performed under the supervision of skilled endoscopists. The diagnostic criteria include monitoring serum pancreatic enzyme levels postprocedure, and early computed tomography is advised in suspected cases. For treatment, the guidelines recommend following acute pancreatitis protocols. Key preventive measures include the use of temporary pancreatic duct stents and rectal nonsteroidal anti-inflammatory drugs, both of which are supported by strong evidence for reducing the incidence of PEP. Overall, these guidelines aim to enhance clinical outcomes by reducing PEP incidence and improving its management through evidence-based practices.

OBJECTIVES: This retrospective multicenter study aimed to clarify the clinical impact of endotherapy for painless pancreatic duct (PD) stones compared with that in patients who received conservative treatment without endotherapy. METHODS: We enrolled 268 patients suffering from chronic pancreatitis with painless PD stones (145 with endotherapy and 123 without endotherapy) and evaluated the impact of endotherapy for painless PD stones on clinical and radiological outcomes. RESULTS: When conservative treatment without endotherapy was set as a reference, complete clearance of the targeted PD stones decreased the relative risk for atrophy of pancreatic parenchyma after inclusion (hazard ratio [HR] 0.42; 95% confidence interval [CI] 0.21-0.84). Incomplete clearance of the targeted PD stones was identified as a risk factor for new-onset or worsening of diabetes (HR 2.08; 95% CI 1.10-3.91) and inducement of pain attack (HR 4.03; 95% CI 1.45-11.19), although complete clearance was not correlated with these outcomes. CONCLUSION: In chronic pancreatitis patients with painless PD stones, endotherapy with complete stone clearance allows the maintenance of pancreatic parenchymal volume. However, if complete clearance fails, endotherapy could lead to aggravation of glucose tolerance and pain attacks during follow-up.

BACKGROUND/OBJECTIVES: Acute pancreatitis (AP) may obscure small pancreatic cancers (PCs) on computed tomography during the acute phase. Surveillance with magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasonography (EUS) may enhance early detection and improve patient outcomes. This study evaluated the impact of early MRCP/EUS surveillance on PC outcomes in AP patients and identified high-risk subgroups for early screening. METHODS: We retrospectively analyzed 1562 AP patients treated between 2010 and 2021, categorizing them into early surveillance (MRCP/EUS within three months of AP onset; n = 760) and nonearly surveillance groups (n = 802). Key outcomes included time to PC diagnosis, surgical resection rate, tumor stage, and overall survival. Multivariate analysis was performed to identify risk factors for concealed PC in AP patients. RESULTS: Among 27 PC cases analyzed, the early surveillance group achieved significantly earlier diagnosis, higher surgical resection rates, increased detection of early-stage PC, and improved overall survival compared with the nonearly surveillance group. Multivariate analysis revealed that subthreshold main pancreatic duct (MPD) dilation (≥2.5 mm) and moderately severe AP were significant predictors of PC. CONCLUSIONS: Early MRCP/EUS surveillance in AP patients facilitates timely detection of occult PC and enhances patient prognosis. These findings support prioritizing early surveillance for AP patients with subthreshold MPD dilation and moderately severe disease. Further large-scale studies are warranted to validate these strategies in clinical practice.

BACKGROUND: Intraductal papillary mucinous neoplasms (IPMNs) are classified into three epithelial types with distinct biological behaviors. However, their effects on the postoperative outcomes remain unclear. METHODS: This multicenter retrospective study included 556 patients with IPMNs who underwent surgical resection. The epithelial types were categorized into the gastric (n = 323), intestinal (n = 160), and pancreatobiliary (n = 73) types. Their associations with the development of extrapancreatic lesions; remnant high-risk lesions (HRLs), including metachronous pancreatic ductal adenocarcinoma (PDAC); and disease-specific survival (DSS) were analyzed. RESULTS: Fifty-one patients (9.2%) developed extrapancreatic lesions. The 10-year cumulative incidence rates for the gastric, intestinal, and pancreatobiliary types were 9.3%, 9.1%, and 32.0%, respectively (P < 0.001). Multivariate analysis identified invasive carcinoma, the gastric, and pancreatobiliary types as independent predictors. Among 516 patients who did not undergo total pancreatectomy, 40 (7.8%) and 13 (2.5%) developed HRLs and metachronous PDAC, respectively. The 10-year cumulative incidence rates of HRLs and metachronous PDAC for the gastric, intestinal, and pancreatobiliary types were 7.0%, 16.2%, and 37.2% and 1.8%, 3.7%, and 22.7%, respectively (P = 0.001 and P = 0.012). In multivariate analysis, the pancreatobiliary type was an independent predictor of metachronous PDAC. Five-year DSS rates for the gastric, intestinal, and pancreatobiliary types were 92.5%, 96.0%, and 76.1% (P < 0.001), respectively. Multivariate analysis identified invasive carcinoma, the gastric, and pancreatobiliary types as independent prognostic factors for DSS. CONCLUSIONS: IPMN epithelial type can independently affect postoperative outcomes. In particular, the pancreatobiliary type has significant impact on the development of metachronous PDAC. Therefore, postoperative surveillance should be tailored according to the epithelial type.

BACKGROUND AND AIMS: Endoscopic ultrasound (EUS)-guided transmural drainage with on-demand endoscopic necrosectomy (EN) is increasingly utilized to manage walled-off necrosis (WON). It has not been fully elucidated how EN and its timing are correlated with treatment outcomes compared to the drainage-based approach. METHODS: Within a multi-institutional cohort of 423 patients with pancreatic fluid collections including 227 patients with WON, we identified 153 patients who received the step-up treatment following the initial EUS-guided drainage of symptomatic WON, including 102 EN patients and 51 non-EN (drainage) patients. Using the competing-risks multivariable proportional hazards regression model with adjustment for potential confounders, we calculated subdistribution hazard ratios (SHRs) for clinical treatment success (WON resolution) by the use of EN and its timing. RESULTS: Compared to drainage alone, the EN-based treatment was associated with a shorter time to clinical success with a multivariable SHR of 1.66 (95% confidence interval, 1.12-2.46). Despite a higher risk of procedure-related bleeding in the EN group, there were no differences in the rates of severe adverse events (7.8% vs. 5.9% in the EN and non-EN groups, respectively) and mortality (6.9% vs. 9.8%). In the EN-treated patients, the timing of EN was not statistically significantly associated with the time to clinical success (Ptrend = 0.34) CONCLUSION: Among patients receiving EUS-guided treatment of symptomatic WON, the use of EN in addition to drainage procedures was associated with earlier disease resolution. Further research is desired to determine the optimal timing of initiating EN considering a risk-benefit balance and cost-effectiveness.

BACKGROUND AND AIMS: EUS-guided hepaticogastrostomy (EUS-HGS) carries a risk of serious adverse events (AEs). A newly designed, partially covered laser-cut stent with antimigration anchoring hooks and a thin tapered tip (7.2F), called a Hook stent, has been developed to prevent serious AEs associated with EUS-HGS. The present prospective multicenter clinical trial evaluated the efficacy and safety of the Hook stent for EUS-HGS after failure of ERCP in patients with unresectable malignant biliary obstruction. METHODS: The primary endpoint was the rate of clinical success, and the secondary endpoints were the rates of technical success, AEs, recurrent biliary obstruction (RBO), procedure success without using a tract dilation device, re-intervention for RBO, time to RBO (TRBO) and overall survival (OS). RESULTS: A total of 38 patients underwent EUS-HGS using the Hook stent. Its technical and clinical success rates in patients undergoing EUS-HGS were 100% and 92.1%, respectively. The procedure success rate without using a tract dilation device was 94.7%. Four (10.5%) patients developed early AEs, but there were no severe AEs such as stent migration. RBO developed in 26.3% of patients. Re-intervention for RBO had a 100% success rate. The median TRBO was not reached, and the median OS was 191 days. CONCLUSIONS: EUS-HGS using the Hook stent demonstrated a high clinical success rate, a low rate of early AEs, and an acceptable stent patency. The Hook stent is safe and feasible for use in patients undergoing EUS-HGS.

ABSTRACT Background Immune checkpoint inhibitors have demonstrated efficacy against various cancers; however, there is a rising incidence of immune‐related colitis. Some cases of immune‐related colitis prove resistant to treatment, even with the administration of glucocorticoids or infliximab, and there is currently no established standard treatment for such cases. Case The patient, a 73‐year‐old male, had undergone combination therapy for malignant pleural mesothelioma for 2 years, utilizing both ipilimumab (a CTLA‐4 inhibitor) and nivolumab (a PD‐1 inhibitor). Unfortunately, the treatment led to side effects, specifically immune‐related adverse event (irAE) enterocolitis. Steroid and infliximab treatment failed to improve the patient's condition. Treatment with tacrolimus was attempted, but the patient remained unresponsive. Subsequently, 45 mg of upadacitinib, a Janus kinase (JAK) inhibitor, was administered. Symptoms improved rapidly following upadacitinib administration, and endoscopy also revealed positive results. With the increasing incidence of immune‐related colitis, some patients have become resistant to treatment with glucocorticoids and infliximab. In this case, the irAE enterocolitis was improved by upadacitinib administration. Conclusion In cases where immune‐related colitis proves resistant to treatment with glucocorticoids, infliximab, or tacrolimus, upadacitinib represents a potential option as a JAK inhibitor.

BACKGROUND AND STUDY AIMS: Endoscopic ultrasonography (EUS)-guided ethanol injection (EI) has recently been introduced as one of the management strategies for pancreatic neuroendocrine neoplasms (PNENs). However, its role as a surgical alternative is unclear. We evaluated the efficacy and safety of EUS-EI in treating small PNENs through a prospective multicentre study. PATIENTS AND METHODS: Patients with Grade 1 tumours of ≤15 mm confirmed by pathology were included. The primary endpoint assessed efficacy and safety, measuring complete ablation using computed tomography at 1 and 6 months, prevention of adverse events (AEs) within 1 month, severe pancreatic fistula at 1 month, and diabetes mellitus (DM) incidence/worsening at 6 months. The composite endpoint of EUS-EI was compared with that of historical results of a study based on surgical treatment. RESULTS: Twenty-five patients with PNENs, with a median tumour size of 10.1 mm, were treated using EUS-EI. Seventy-six percent of the patients achieved the composite primary endpoint (19/25) (95% confidence interval [CI]=54.9%-90.6%), a proportion significantly higher than that of surgical treatment (P=0.0083). Regarding efficacy, 88% (22/25) of the patients achieved complete ablation at 1 and 6 months (95% CI=68.8%-97.5%). Regarding safety, 96% (24/25) of the patients had no severe AEs within 1 month (95% CI=79.7%-99.9%). No patients had severe pancreatic fistulas at 1 month, and 84% (21/25) of the patients had no incidence or exacerbation, or both, of DM at 6 months (95% CI=63.9%-95.5%). CONCLUSION: EUS-EI is safe and could be a potent treatment option for patients with small PNENs.

Background: Although several reports have compared the outcomes of self-expandable metallic stent (SEMSs) and transanal decompression tube (TDT) placement for malignant colorectal obstruction (MCO), few studies have compared the radiation exposure (RE) associated with these two procedures. Consequently, we aimed to compare the RE of SEMS and TDT placements for MCO using propensity score matching (PSM) in a multi-center, prospective observational study. Methods: This study investigated the clinical data of 236 patients who underwent SEMS or TDT placement. The air kerma at the patient entrance reference point (Ka,r: mGy) and air kerma–area product (PKA; Gycm2) were measured and compared between SEMS and TDT groups after PSM. Results: After PSM, 61 patients were identified in each group. The median Ka,r in the SEMS group was significantly greater than that in the TDT group (77.4 vs. 55.6 mGy; p = 0.025) across the entire cohort. With respect to subgroup analyses by location, in the rectum, the median Ka, r and PKA were significantly greater in the SEMS group than in the TDT group (172.9 vs. 34.6 mGy; p = 0.001; and 46.0 vs. 18.1 Gycm2; p = 0.006, respectively). However, in the colon, the RE parameters did not significantly differ between the two groups. Conclusions: TDT might be a more suitable option for decompression in patients with malignant rectal obstruction due to its lower RE and technical advantages. Conversely, SEMS placement is recommended as the first decompression method to treat malignant colonic obstruction, in line with the current guidelines.

INTRODUCTION: Disconnected pancreatic duct syndrome (DPDS) is a pathological condition that causes various symptoms due to the continuous secretion of pancreatic enzymes from the pancreas upstream, which has been separated due to disconnection of the pancreatic duct (DPD) for various reasons.Acute necrotizing pancreatitis includes a certain probability of DPDS appearance, which makes it necessary to provide various treatments for DPDS. Furthermore, DPDS can impact long-term results, such as recurrence and impaired pancreatic function. Although the development of various modalities has contributed to diagnosis and treatment, especially less invasive endoscopic therapy, DPDS is often overlooked, and the diagnosis can be delayed due to the lack of consensus on its definition and classification. This review summarizes the current knowledge and challenges of DPDS and discusses the optimal strategy for its diagnosis and treatment, as well as future perspectives. AREAS COVERED: Given the lack of established definition, diagnosis, and treatment of DPDS, we conducted a thorough review of the existing literature. EXPERT OPINION: It is emphasized that a standardized definition and classification of DPDS is essential for designing and conducting clinical studies to address current unmet needs in managing patients with DPDS.

OBJECTIVES: The appropriate holistic management is mandatory for successful endoscopic ultrasound (EUS)-guided treatment of pancreatic fluid collections (PFCs). However, comorbidity status has not been fully examined in relation to clinical outcomes of this treatment. METHODS: Using a multi-institutional cohort of 406 patients receiving EUS-guided treatment of PFCs in 2010-2020, we examined the associations of Charlson Comorbidity Index (CCI) with in-hospital mortality and other clinical outcomes. Multivariable logistic regression analysis was conducted with adjustment for potential confounders. The findings were validated using a Japanese nationwide inpatient database including 4053 patients treated at 486 hospitals in 2010-2020. RESULTS: In the clinical multi-institutional cohort, CCI was positively associated with the risk of in-hospital mortality (Ptrend < 0.001). Compared to patients with CCI = 0, patients with CCI of 1-2, 3-5, and ≥6 had adjusted odds ratios (95% confidence intervals) of 0.76 (0.22-2.54), 5.39 (1.74-16.7), and 8.77 (2.36-32.6), respectively. In the nationwide validation cohort, a similar positive association was observed; the corresponding odds ratios (95% confidence interval) were 1.21 (0.90-1.64), 1.52 (0.92-2.49), and 4.84 (2.63-8.88), respectively (Ptrend < 0.001). The association of higher CCI with longer length of stay was observed in the nationwide cohort (Ptrend < 0.001), but not in the clinical cohort (Ptrend = 0.18). CCI was not associated with the risk of procedure-related adverse events. CONCLUSIONS: Higher levels of CCI were associated with a higher risk of in-hospital mortality among patients receiving EUS-guided treatment of PFCs, suggesting the potential of CCI in stratifying the periprocedural mortality risk. TRIAL REGISTRATION: The research based on the clinical data from the WONDERFULcohort was registered with UMIN-CTR (registration number UMIN000044130).

BACKGROUND: Focal pancreatic parenchymal atrophy (FPPA) and upstream pancreatic atrophy (UPA) may indicate the presence of early pancreatic cancer. In early pancreatic cancer, the tumor occasionally spreads laterally along the main pancreatic duct, presenting challenges in determining the extent of surgical resection. This study aimed to investigate the association of pancreatic atrophy pattern and intraductal cancer extension. METHODS: Thirty-two patients with early-stage pancreatic cancer who underwent surgery at five participating centers were enrolled. Pancreatic atrophy was defined as the narrowing of parenchyma compared to the surrounding parenchyma and was classified as either FPPA (partial atrophy surrounding the pancreatic duct stenosis) or UPA (global atrophy caudal to the site of duct stenosis). Intraductal cancer extension was defined as an extension exceeding 10 mm. RESULTS: Preoperative computed tomography revealed FPPA, UPA, and no parenchymal atrophy in 13, 13, and 6 patients. Cases with FPPA or UPA showed significantly longer cancer extensions than those without atrophy (P = 0.005 and P = 0.03, respectively). Intraductal cancer extension was present in all but one case of FPPA. 69% (9/13) of the cases with UPA showed intraductal cancer extension, whereas cases without atrophy showed no intraductal cancer extension. Importantly, two patients with FPPA or UPA showed positive resection margins during surgery and three patients with FPPA or UPA showed recurrence in the remnant pancreas. CONCLUSIONS: The presence of FPPA and UPA indicates lateral cancer extension in early-stage pancreatic cancer. Preoperative assessment of the pancreatic parenchyma may provide valuable insights for determining the extent of surgical resection.

BACKGROUND: Endoscopic ultrasound (EUS)-guided transluminal drainage has become a first-line treatment modality for symptomatic pancreatic pseudocysts. Despite the increasing popularity of lumen-apposing metal stents (LAMSs), plastic stents may resolve non-necrotic fluid collections effectively with lower costs and no LAMS-specific adverse events. To date, there has been a paucity of data on the appropriate stent type in this setting. This trial aims to assess the non-inferiority of plastic stents to a LAMS for the initial EUS-guided drainage of pseudocysts. METHODS: The WONDER-02 trial is a multicentre, open-label, non-inferiority, randomised controlled trial, which will enrol pancreatic pseudocyst patients requiring EUS-guided treatment in 26 centres in Japan. This trial plans to enrol 80 patients who will be randomised at a 1:1 ratio to receive either plastic stents or a LAMS (40 patients per arm). In the plastic stent group, EUS-guided drainage will be performed using two 7-Fr double pigtail stents. In the LAMS group, the treatment will be performed in the same way except for LAMS use. The step-up treatment will be performed via endoscopic and/or percutaneous procedures at the trial investigator's discretion. The primary endpoint is clinical success, which is defined as a decrease in a pseudocyst size to ≤ 2 cm and an improvement in inflammatory indicators (i.e. body temperature, white blood cell count, and serum C-reactive protein). Secondary endpoints include technical success, adverse events including mortality, pseudocyst recurrence, and medical costs. DISCUSSION: The WONDER-02 trial will investigate the efficacy and safety of plastic stents compared to a LAMS in EUS-guided treatment of symptomatic pancreatic pseudocysts with a particular focus on the non-inferior efficacy of plastic stents. The findings will help establish a new treatment algorithm for this population. TRIAL REGISTRATION: ClinicalTrials.gov NCT06133023 registered on 9 November 2023. UMIN000052647 registered on 30 October 2023. jRCT1032230444 registered on 7 November 2023.

Interventional EUS治療は長い年月を経て，大きくその可能性を広げ，現在臨床で行われるものとして多くの治療手技が存在する．さらに近年の専用スコープ・デバイスの機器開発は手技の難易度を下げ，安全性を向上させ，Interventional EUS治療を以前よりも偶発症が少ない安全なものに進化させている．一方で教育の問題，保険適応といった問題は解決しておらず，さらに安全で簡便な治療となるためには，今後も従来の治療（ERCPや手術）との比較検討を行いながら，慎重な手技施行を心掛け，患者に最も貢献できるInterventional EUS治療は何か，を追求し続けていく姿勢が求められる．

BACKGROUND: Patients with isolated IgG4-related sclerosing cholangitis (IgG4-SC) often undergo unnecessary resection. The aim of this study was to validate the revised Japanese diagnostic criteria for isolated IgG-4-SC and to improve awareness about this condition in the population. METHODS: This was a Japanese retrospective multicenter study. We focused on the data and diagnostic yield obtained using the Japanese diagnostic criteria published initially in 2012 and revised later in 2020 for the diagnosis of isolated IgG4-SC. RESULTS: Patients with isolated IgG4-SC could be classified into two groups based on the primary location of the lesion: the hilar type (n = 40) and the extrahepatic type (n = 13). In total, 10 patients with the hilar type had undergone unnecessary resection. The revised 2020 criteria are useful for the diagnosis of extrahepatic lesions, which are not included in the 2012 criteria. The need for a steroid trial was reduced from 37.7% when the diagnosis was based on the 2012 criteria to 7.6% when the diagnosis was based on the revised 2020 criteria. The diagnostic specificity also improved from 58.5% for the 2012 criteria to 88.7% for the revised 2020 criteria. CONCLUSION: Our validation of the 2020 criteria for the diagnosis of IgG4-SC could contribute to avoiding unnecessary resection in patients with isolated IgG4-SC, which can be classified into the hilar and extrahepatic types. The 2020 criteria can enhance the diagnosis rate of isolated IgG4-SC and uncover this tough-to-diagnose entity based on inclusion of the imaging findings and decrease the dependence on a steroid trial.

BACKGROUND: One advantage of endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) is that it is difficult for reflux cholangitis, caused by duodenal pressure increasing due to duodenal obstruction, to occur. In addition, since stent deployment is performed away from the malignant stricture site, longer stent patency than with endoscopic retrograde cholangiopancreatography (ERCP) may be obtained. However, no study has previously compared EUS-HGS and ERCP for patients without duodenal obstruction or surgically altered anatomy. The aim of the present study was to compare clinical outcomes between EUS-HGS and ERCP in normal anatomy patients without duodenal obstruction. METHOD: In the ERCP group, patients who initially underwent biliary drainage were included. In the EUS-HGS group, patients who underwent EUS-HGS due to failed biliary cannulation were included. Patients with an inaccessible papilla, such as with surgically altered anatomy or duodenal obstruction, were excluded. RESULTS: A total of 314 patients who underwent ERCP and EUS-HGS were enrolled in this study. Of the 314 patients, 289 underwent biliary stenting under ERCP guidance, and 25 patients underwent biliary stenting under EUS-HGS. After propensity score-matching analysis, the adverse event rate tended to be lower in the EUS-HGS group than in the ERCP group. Although overall survival was not significantly different between the EUS-HGS and ERCP groups (p = .228), stent patency was significantly longer in the EUS-HGS group (median 366.0 days) than in the ERCP group (median 76.5 days). CONCLUSIONS: EUS-HGS had a lower adverse event rate, shorter procedure time, and longer stent patency than ERCP in cases of normal anatomy without duodenal obstruction.

The progress of endoscopic diagnosis and treatment for inflammatory diseases of the biliary tract and pancreas have been remarkable. Endoscopic ultrasonography (EUS) and EUS-elastography are used for the diagnosis of early chronic pancreatitis and evaluation of endocrine and exocrine function in chronic pancreatitis. Notably, extracorporeal shock wave lithotripsy and electrohydraulic shock wave lithotripsy have improved the endoscopic stone removal rate in patients for whom pancreatic stone removal is difficult. Studies have reported the use of self-expanding metal stents for stent placement for pancreatic duct stenosis and EUS-guided pancreatic drainage for refractory pancreatic duct strictures. Furthermore, EUS-guided drainage using a double-pigtailed plastic stent has been performed for the management of symptomatic pancreatic fluid collection after acute pancreatitis. Recently, lumen-apposing metal stents have led to advances in the treatment of walled-off necrosis after acute pancreatitis. EUS-guided biliary drainage is an alternative to refractory endoscopic biliary drainage and percutaneous transhepatic biliary drainage for the treatment of acute cholangitis. The placement of an inside stent followed by switching to uncovered self-expanding metal stents in difficult-to-treat cases has been proposed for acute cholangitis by malignant biliary obstruction. Endoscopic transpapillary gallbladder drainage is an alternative to percutaneous transhepatic gallbladder drainage for severe and some cases of moderate acute cholecystitis. EUS-guided gallbladder drainage has been reported as an alternative to percutaneous transhepatic gallbladder drainage and endoscopic transpapillary gallbladder drainage. However, it is important to understand the advantages and disadvantages of each drainage method and select the optimal drainage method for each case.

The prognostic factors associated with severe-to-fatal post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) remain unclear despite the extensive number of studies on PEP. In total, 3739 ERCP patients with biliary disease with an intact papilla and indicated for ERCP were prospectively enrolled at 36 centers from April 2017 to March 2018. Those with acute pancreatitis diagnosed before ERCP, altered gastrointestinal anatomy, and an American Society of Anesthesiologists (ASA) physical status > 4 were excluded. Univariate and multivariate logistic regression analyses were performed on patient-related factors, operator-related factors, procedure-related factors, and preventive measures to identify potential prognostic factors for severe-to-fatal PEP. Multivariate analyses revealed pancreatic guidewire-assisted biliary cannulation (OR 13.59, 95% CI 4.21-43.83, p < 0.001), post-ERCP non-steroidal anti-inflammatory drug (NSAID) administration (OR 11.54, 95% CI 3.83-34.81, p < 0.001), and previous pancreatitis (OR 6.94, 95% CI 1.45-33.33, p = 0.015) as significant risk factors for severe-to-fatal PEP. Preventive measures included endoscopic biliary sphincterotomy (EST; OR 0.29, 95% CI, 0.11-0.79, p = 0.015) and prophylactic pancreatic stents (PPSs; OR 0.11, 95% CI, 0.01-0.87, p = 0.036). In biliary ERCP, pancreatic guidewire-assisted biliary cannulation, NSAID administration after ERCP, and previous pancreatitis were risk factors for severe-to-fatal PEP, whereas EST and PPS were significant preventive measures for severe-to-fatal PEP.

Background and study aims Recent advances in endoscopic transmural treatment have improved the clinical outcomes of patients with pancreatic fluid collections (PFCs). However, there is still a debate about the preventive effect of long-term placement of a transmural plastic stent (PS) on recurrence after successful endoscopic ultrasound (EUS)-guided treatment of PFCs. We conducted a systematic review and meta-analysis to evaluate PFC recurrence rates with and without a transmural PS after EUS-guided treatment. Patients and methods A systematic literature search of PubMed, Embase, and the Cochrane database was conducted to identify clinical studies comparing outcomes with and without transmural PS published until September 2022. Data on PFC recurrence and adverse events (AEs) were pooled using a random-effects model. Results Nine studies including 380 patients with long-term transmural PS and 289 patients without PS were identified. The rate of PFC recurrence was significantly lower in patients with transmural PS (pooled odds ratio [OR] = 0.23, 95% confidence interval [CI] [0.08-0.65], P = 0.005). In a subgroup analysis limited to studies focusing on patients with disconnected pancreatic duct syndrome, which has been reported to be a risk factor for PFC recurrence, the OR was numerically lower than that for the entire cohort (OR = 0.14, 95% CI [0.04-0.46]). The rate of AEs was significantly higher with long-term transmural PS (OR = 14.77, 95% CI [4.21-51.83]). Conclusions In this meta-analysis, long-term PS placement reduced the risk of PFC recurrence. Given the potential AEs of indwelling PS, further research is required to evaluate the overall benefits of long-term PS placement.

For pancreatic masses, an evaluation of their vascularity using contrast-enhanced ultrasonography can help improve their characterization. This study was designed to evaluate the utility and safety of contrast-enhanced transabdominal ultrasonography (CE-TUS) and endoscopic ultrasonography (CE-EUS) in the diagnosis of pancreatic masses including solid or cystic masses. This multi-center comparative open-label superiority study is designed to compare Plain (P)-TUS/EUS alone with P-TUS/P-EUS plus CE-TUS/CE-EUS. Three hundred and one patients with a total of 232 solid pancreatic masses and 69 cystic masses were prospectively enrolled. The primary endpoints are to compare the diagnostic accuracy between P-TUS/P-EUS alone and P-TUS/P-EUS plus CE-TUS/CE-EUS for both the TUS and EUS of solid pancreatic masses, and to compare the diagnostic accuracy between P-EUS alone and P-EUS plus CE-EUS in cystic pancreatic masses. The secondary endpoints are to compare the diagnostic sensitivity and specificity of P-TUS/P-EUS alone and P-TUS/P-EUS plus CE-TUS/CE-EUS for pancreatic solid/cystic masses, and the accuracy of P-TUS alone and P-TUS plus CE-TUS for pancreatic cystic masses. Other secondary endpoints included comparing the diagnostic sensitivity, specificity, and accuracy of CE-TUS, CE-EUS and CE-computed tomography (CT) for solid/cystic pancreatic masses. The safety, degree of effective enhancement, and diagnostic confidence obtained with CE-TUS/CE-EUS will also be assessed.

BACKGROUND: Postoperative pancreatic fluid collections (POPFCs) are common adverse events (AEs) after pancreatic surgery and may need interventions. Endoscopic ultrasound (EUS)-guided drainage for POPFCs is increasingly reported, but its appropriate timing has not been fully elucidated. The aim of this meta-analysis was to evaluate treatment outcomes of POPFCs according to the timing of EUS-guided drainage. METHODS: Using PubMed, Embase, Web of Science, and the Cochrane database, we identified clinical studies published until December 2022 with data comparing outcomes of early and delayed EUS-guided drainage for POPFCs. We pooled data on AEs, mortality, and technical and clinical success rates, using the random-effects model. RESULTS: From 1415 papers identified in the initial literature search, we identified 6 retrospective studies, including 128 and 107 patients undergoing early and delayed EUS-guided drainage for POPFCs. The threshold of early and delayed drainage ranged from 14 to 30 days. Distal pancreatectomy was the major cause of POPFCs, ranging from 44 to 100%. The pooled odds ratio (OR) for AEs was 0.81 (95% confidence interval [CI] 0.40-1.64, P = 0.55) comparing early to delayed drainage. There was no procedure-related mortality. Technical success was achieved in all cases and a pooled OR of clinical success was 0.60 (95% CI 0.20-1.83, P = 0.37). CONCLUSION: POPFCs can be managed by early EUS-guided drainage without an increase in AEs.

BACKGROUND: We compared the results of preoperative pancreatic juice cytology (PJC) and final pathological diagnosis after resection in patients who underwent resection of intraductal papillary mucinous neoplasm (IPMN) of the pancreas to determine whether preoperative PJC can help determine therapeutic strategies. METHODS: Of 1130 patients who underwent surgical resection IPMN at 11 Japanese tertiary institutions, the study included 852 patients who underwent preoperative PJC guided by endoscopic retrograde cholangiopancreatography (ERCP). RESULTS: The accuracy of preoperative PJC for differentiation between cancerous and noncancerous lesions were 55% for IPMN overall; 59% for the branch duct type; 49% for the main pancreatic duct type; 53% for the mixed type, respectively. On classifying IPMN according to the diameters of the mural nodule (MN) and main pancreatic duct (MPD), the corresponding values for diagnostic performance were 40% for type 1 (MN ≥5 mm and MPD ≥ 10 mm); 46% for type 2 (MN ≥5 mm and MPD < 10 mm); 61% for type 3 (MN < 5 mm and MPD ≥ 10 mm); 72% for type 4 (MN < 5 mm and MPD < 10 mm), respectively. CONCLUSIONS: PJC in IPMN is not a recommended examination because of its low overall sensitivity and no significant difference in diagnostic performance by type, location, or subclassification. Although the sensitivity is low, the positive predictive value is high, so we suggest that pancreatic juice cytology be performed only in cases where the patient is not sure about surgery.

Abstract Background and Aim Recently, the use of various endoscopic procedures performed under X‐ray fluoroscopy guidance has increased. With the popularization of such procedures, diagnostic reference levels (DRLs) have been widely accepted as the global standard for various procedures with ionizing radiation. The Radiation Exposure from Gastrointestinal Fluoroscopic Procedures (REX‐GI) study aimed to prospectively collect actual radiation exposure (RE) data and establish DRLs in gastrointestinal endoscopy units. In this post hoc analysis of the REX‐GI study, we established DRLs for each disease site by analyzing cases of gastrointestinal enteral metallic stent placement. Methods The REX‐GI study was a multicenter, prospective observational study conducted to collect actual RE data during gastrointestinal enteral metallic stent placement. To establish DRL values for three disease sites, namely the esophagus, gastroduodenum, and colon, we examined fluoroscopy time (FT; min), number of X‐ray images, air kerma at the patient entrance reference point (K_a,r; mGy), and the air kerma–area product (P_KA; Gy cm²) during enteral metallic stent placement. Results Five‐hundred and twenty‐three stenting procedures were performed. The DRL values of FT (min) and the number of X‐ray images for the esophagus/gastroduodenum/colon were 9/16/18 min and 9/15/11 min, respectively. Furthermore, the DRL values of K_a,r and P_KA for each disease site were 43.3/120/124 mGy and 10.3/36.6/48.4 Gy cm², respectively. Among the procedures, esophageal stents were significantly associated with the lowest values (P < 0.001). Conclusion The characteristics of RE vary according to disease site among gastrointestinal enteral metallic stent placements. Thus, it is desirable to set DRL values based on the disease site.

Objectives For preoperative biliary drainage (PBD) of malignant hilar biliary obstruction (MHBO), current guidelines recommend endoscopic nasobiliary drainage (ENBD) due to the higher risk of cholangitis after endoscopic biliary stenting (EBS) during the waiting period before surgery. However, few studies have supported this finding. Therefore, we aimed to compare the outcomes of preoperative ENBD and EBS in patients with MHBO. Methods Patients with MHBO who underwent laparotomy for radical surgery after ENBD or EBS were included from retrospectively collected data from 13 centers (January 2014 to December 2018). We performed a 1:1 propensity score matching between the ENBD and EBS groups. These patients were compared for the following: cholangitis and all adverse events (AEs) after endoscopic biliary drainage (EBD) until surgery, time to cholangitis development after EBD, postsurgical AEs, and in‐hospital death after surgery. Results Of the 414 patients identified, 355 were analyzed in this study (226 for ENBD and 129 for EBS). The matched cohort included 63 patients from each group. The proportion of cholangitis after EBD was similar between the two groups (20.6% vs. 25.4%, P = 0.67), and no significant difference was observed in the time to cholangitis development. The proportions of surgical site infections, bile leaks, and in‐hospital mortality rates were similar between the groups. Conclusion For PBD of MHBO, the proportion of AEs, including cholangitis, after EBD until surgery was similar when either ENBD or EBS was used.

OBJECTIVES: We aimed to clarify the clinical utility of measuring serum pancreatic enzymes after endoscopic retrograde cholangiopancreatography (ERCP) for the purpose of predicting post-ERCP pancreatitis (PEP) by a meta-analysis of diagnostic test accuracy studies. METHODS: Studies on the prediction accuracy of PEP by serum amylase or lipase measured at 2, 3, and 4 h after ERCP were collected. A literature search was performed in PubMed and the Cochrane Library database for studies published between January 1980 and March 2023. The quality of individual studies was evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2. Data were analyzed using Meta-DiSc 2.0 software. RESULTS: We searched the databases and identified 20 observational studies (12,313 participants). PEPs were defined according to criteria by Cotton or modified Cotton, revised Atlanta criteria, or the Japanese criteria. Meta-analysis of eight studies (4389 participants) showed a pooled sensitivity of 71.1% (95% confidence interval [CI] 56.1-82.5) and pooled specificity of 91.2% (95% CI 85.9-94.6) for the serum amylase cut-off value at 3 times the upper limit of normal (ULN). Another meta-analysis of five studies (1970 participants) showed a pooled sensitivity of 85.8% (95% CI 61.9-95.7) and pooled specificity of 85.3% (95% CI 81.9-88.1) for the serum lipase cut-off value at 3 times ULN. CONCLUSION: Despite a high risk of bias due to various reference standards, this updated meta-analysis and the utility assessment by a decision tree showed the utility of serum amylase or lipase levels more than 3 times ULN measured 2-4 h after ERCP for predicting PEP.

Introduction: Ustekinumab is an IgG1 kappa monoclonal antibody directed against the common p40 subunit of interleukin-12 and interleukin-23, which activate Th1- and Th17-mediated immune responses, respectively. It has proven efficacy for the treatment of moderate to severe ulcerative colitis (UC) in the UNIFI Phase III clinical trial; however, data on its efficacy in the real world is limited. In this study, we aimed to assess the real-world efficacy of ustekinumab.Methods: This observational study included 30 patients with UC who received ustekinumab from April 2020 to April 2022. We examined demographic information, disease type and activity (Mayo score, partial Mayo score [PMS]), use of biologics, concomitant use of predonisolone (PSL), 8-week ustekinumab clinical response rate, remission induction rate, 44- and 152-week remission maintenance rate, continuation rate, and 44-week steroid-free remission rate. The primary outcomes were the short- and long-term efficacy of ustekinumab.Results: Included patients (53% women; mean age: 41.2 years [16–80 years]) had an average disease duration of 86 weeks. Mayo’s score (median) was 7.4 and the PMS was 5.4. Two (7%), 24 (80%), and four (13%) patients had a Mayo endoscopic sub-score (MES) of MES1, MES2, and MES3, respectively. The median serum CRP was 1.0 mg/dL. Five patients had no history of biotherapy (naive), while 8 and 17 had a history of one and two or more biologic agents, respectively. Eight patients were PSL-resistant and 22 were PSL-dependent. The 8-week clinical response rate was 73%, and the clinical remission induction rate was 70%. The remission maintenance rates at 44 and 152 weeks were 67% and 63%, respectively. The ustekinumab retention rate was 67% (86-week mean follow-up period). Regarding biologic failure cases, the clinical response rate in the failure group with up to one biologic agent (including naive cases) was 84.6%, which was higher than the 58.0% rate in the failure group with two or more biologic agents (p=0.06). Steroid-free remission rates at 44 and 152 weeks were 63% each. In the logistic regression analysis parameters for discontinuation of ustekinumab, only PMS remained significant after multivariate analysis (p=0.018).Conclusion: Our study showed short-term and long-term ustekinumab effectiveness, especially with comparative low disease activity.

OBJECTIVES: No comprehensive study has examined short- and long-term adverse outcomes of endoscopic ultrasound (EUS)-guided treatment of pancreatic fluid collections (PFCs) including walled-off necrosis (WON) and pseudocysts. METHODS: In a multi-institutional cohort of 357 patients receiving EUS-guided treatment of PFCs (228 with WON and 129 with pseudocysts), we examined PFC type-specific risk factors for procedure-related adverse events (AEs), clinical failure, and recurrence. Odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (CIs) were computed using the logistic and Cox regression models, respectively, adjusting for potential confounders. RESULTS: AEs were observed predominantly in WON, and risk factors were WON extension to the pelvis (OR, 2.49; 95% CI, 1.00-6.19) and endoscopic necrosectomy (OR, 5.15; 95% CI, 1.61-16.5). Risk factors for clinical failure in WON treatment included higher Charlson Comorbidity Index (OR for ≥3 vs. ≤2, 2.58; 95% CI, 1.05-6.35), extension to the pelvis (OR, 3.63; 95% CI, 1.57-8.43), non-use of a lumen-apposing metal stent (OR, 2.88; 95% CI, 1.10-7.54), and percutaneous drainage (OR, 3.73; 95% CI, 1.27-10.9). Patients with pseudocysts extending to the paracolic gutter and need for more than two endoscopic / percutaneous procedures had ORs for clinical failure of 5.28 (95% CI, 1.10-25.3) and 5.52 (95% CI, 1.61-18.9), respectively. Pseudocysts requiring the multigateway approach were associated with high risk of recurrence (HR, 4.00; 95% CI, 1.11-11.6). CONCLUSIONS: The adverse outcomes at various phases of EUS-guided PFC treatment may be predictable based on clinical parameters. Further research is warranted to optimize treatment strategies for high-risk patients (registration number, UMIN000044130).

Abstract Background and Aim A multicenter, open‐label randomized Phase II trial was conducted to determine whether low‐dose gemcitabine plus nab‐paclitaxel (GnP) could improve tolerability and show equivalent efficacy to the standard‐dose GnP for elderly patients with metastatic pancreatic cancer. Methods Consecutive patients aged ≥65 years with metastatic pancreatic cancer who presented at one of four Japanese referral centers between November 2016 and January 2021 were enrolled. The 60 patients were randomly assigned to low‐ or standard‐dose groups with a 1:1 ratio. Patients in the low‐dose GnP group received gemcitabine at a dose of 250 mg/m² and nab‐paclitaxel at 125 mg/m². Results Low‐dose GnP significantly decreased the rate of cases requiring dose reduction (16.7% vs 63.3%). The response rate (36.7% vs 33.3%) and progression‐free survival (7.3 vs 8 months) were comparable between the low‐ and standard‐dose groups as determined by independent review. The difference in the median overall survival between the two groups was not significant (7.9 vs 12 months). The proportion of patients with hematologic and non‐hematologic treatment‐related adverse events was comparable between the two groups. Conclusion Low‐dose GnP had an equivalent efficacy to conventional therapy; however, it did not reduce adverse events.

BACKGROUND AND AIM: Endoscopic placement of self-expandable metal stents (SEMSs) for malignant distal biliary obstruction (MDBO) may be accompanied by several types of adverse events. The present study analyzed the adverse events occurring after SEMS placement for MDBO. METHODS: The present study retrospectively investigated the incidence and types of adverse events in patients who underwent SEMS placement for MDBO between April 2018 and March 2021 at 26 hospitals. Risk factors for acute pancreatitis, cholecystitis, and recurrent biliary obstruction (RBO) were evaluated by univariate and multivariate analyses. RESULTS: Of the 1425 patients implanted with SEMS for MDBO, 228 (16.0%) and 393 (27.6%) experienced early adverse events and RBO, respectively. Pancreatic duct without tumor involvement (p = 0.023), intact papilla (p = 0.025), and SEMS placement across the papilla (p = 0.037) were independent risk factors for acute pancreatitis. Tumor involvement in the orifice of the cystic duct (OCD) was an independent risk factor for cholecystitis (p < 0.001). Fully and partially covered SEMSs were independent risk factors for food impaction and/or sludge. Fully covered SEMS was an independent risk factor for stent migration. Uncovered SEMS and laser-cut SEMS were independent risk factors for tumor ingrowth. CONCLUSIONS: Pancreatic duct without tumor involvement, intact papilla, and SEMS placement across the papilla were independent risk factors for acute pancreatitis, and tumor involvement to the OCD was an independent risk factor for cholecystitis. The risk factors for food impaction and/or sludge, stent migration, and tumor ingrowth differed among types of SEMS.

BACKGROUND AND AIMS: The diagnostic performance of endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNAB) for pancreatic ductal adenocarcinoma (PDAC) ≤ 10 mm in diameter is relatively low. Pancreatic juice cytology (PJC) has gained attention owing to its high sensitivity for small PDAC. We aimed to clarify the diagnostic ability of EUS-FNAB and the salvage ability of PJC for PDAC ≤ 10 mm. METHODS: The data obtained from attempted EUS-FNAB for patients with EUS-confirmed pancreatic tumors ≤ 10 mm (excluding pancreatic metastases/malignant lymphomas) were retrospectively analyzed. Patients who experienced technical failure/negative EUS-FNAB result and had a strong likelihood of PDAC based on imaging characteristics underwent PJC. PDAC was diagnosed using resected histological specimens, EUS-FNAB-positive tumor growth on the imaging examination, or additional EUS-FNAB-positive results after increase in tumor size. The primary endpoint was the diagnostic ability of EUS-FNAB for PDAC ≤ 10 mm. The salvage ability of PJC was also assessed. RESULTS: Overall, 86 patients were diagnosed with PDAC of 271 patients with pancreatic tumors ≤ 10 mm who underwent attempted EUS-FNAB. The technical success rate, sensitivity, specificity, and accuracy of EUS-FNAB for PDAC ≤ 10 mm was 80.8%, 82.3%, 94.9%, and 91.3%, respectively. Among the 35 PDAC patients who experienced technical failure/false-negative result of EUS-FNAB, 26 (74.3%) were correctly diagnosed using salvage PJC. CONCLUSIONS: The true success rate/sensitivity of EUS-FNAB for PDAC ≤ 10 mm was relatively low. When EUS-FNAB for a pancreatic lesion ≤ 10 mm strongly suspected to be PDAC is unsuccessful or yields a negative result, PJC is recommended.

BACKGROUND: This prospective cohort study evaluated the feasibility of using endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) samples for comprehensive mutational analysis of cancer-related genes using microtissues. METHODS: Fifty patients with suspected pancreatic cancer presenting consecutively at the Kindai University Hospital between January 2018 and January 2019 were enrolled. Cancerous tissues from EUS-FNB were obtained from each tumor and subjected to histological examination and mutational analysis. The primary endpoint was the collection rate of EUS-FNB specimens suitable for comprehensive cancer panels using deep sequencing. Clinical history and genetic variations between the disease control and progressive disease groups of patients on chemotherapy were evaluated as secondary endpoints. RESULTS: The collection rate of EUS-FNB specimens suitable for comprehensive cancer panels using deep sequencing was 93.6%. The cancer panel was sequenced for 25 patients with pancreatic cancer treated initially with systemic chemotherapy. Mutation in p53 and Smad4 were positively and negatively associated, respectively, with disease control at the initial evaluation. The median time to progression in 15 patients with p53 and without Smad4 mutations was 182.0 days; whereas, it was 92.5 days in other 10 patients; this difference was significant (p = 0.020). CONCLUSIONS: Tissue samples from EUS-FNB were suitable for mutational analysis. Pancreatic cancers with p53 and without Smad4 mutations responded better to chemotherapy and had a better prognosis than those others.

Abstract Background and Aim Serum leucine‐rich alpha‐2 glycoprotein level has been reported to be a useful biomarker in assessing mucosal healing in patients undergoing biotherapy, where mucosal lesions caused by ulcerative colitis are difficult to assess endoscopically. However, no such reports have been reported in biotherapy‐naïve cases. Methods Sixty‐eight patients with ulcerative colitis (UC) who were biotherapy‐naïve at Kindai University Hospital between October 2021 and October 2022 were enrolled. We prospectively examined the correlation between leucine‐rich alpha‐2 glycoprotein (LRG), C‐reactive protein (CRP), erythrocyte sedimentation rate (ESR), and Geboes scores with clinical endoscopic activity using the Mayo endoscopic subscore (MES). Results Mucosal healing was achieved in 39 (57%) patients. Univariate analysis revealed that the factors associated with mucosal healing were LRG (P = 0.0024), CRP (P = 0.1078), ESR (P = 0.0372), and Geboes scores (P = 0.0075). Logistic regression analysis identified LRG and Geboes scores as independent factors associated with mucosal healing assessed using MES (P = 0.0431 for LRG and P = 0.0166 for Geboes scores). Conclusion LRG was found to be the easiest marker to monitor disease activity and mucosal inflammation in UC patients with biotherapy‐naïve cases, with a performance equivalent to that of Geboes scores.

Pancreatic cancer primarily arises from microscopic precancerous lesions, such as pancreatic intraepithelial neoplasia (PanIN) and acinar-to-ductal metaplasia (ADM). However, no established method exists for predicting pancreatic precancerous conditions. Endoscopic ultrasonography (EUS) can detect changes in pancreatic parenchymal histology, including fibrosis. This study aimed to elucidate the relationship between pancreatic parenchymal EUS findings and microscopic precancerous lesions. We retrospectively analyzed 114 patients with pancreatobiliary tumors resected between 2010 and 2020 and evaluated the association between pancreatic parenchymal EUS findings and the number of PanIN, ADM, and pancreatic duct gland (PDG). Of the 114 patients, 33 (29.0%), 55 (48.2%), and 26 (22.8%) had normal EUS findings, hyperechoic foci/stranding without lobularity, and hyperechoic foci/stranding with lobularity, respectively. Multivariate analyses revealed that abnormal EUS findings were significantly associated with the frequency of PanIN (hyperechoic foci/stranding without lobularity: OR [95% CI] = 2.7 [1.0-7.3], with lobularity: 6.5 [1.9-22.5], Ptrend = 0.01) and ADM (hyperechoic foci/stranding without lobularity: 3.1 [1.1-8.2], with lobularity: 9.7 [2.6-36.3], Ptrend = 0.003) but not with PDG (hyperechoic foci/stranding without lobularity: 2.2 [0.8-5.8], with lobularity: 3.2 [1.0-10.2], Ptrend = 0.12). We observed a trend toward a significantly higher number of precancerous lesions in the following order: normal findings, hyperechoic foci/stranding without lobularity, and hyperechoic foci/stranding with lobularity. Pancreatic parenchymal EUS findings were associated with the increased frequency of PanIN and ADM. Lobularity may help predict the increased number of precancerous lesions.

BACKGROUND: With the increasing popularity of endoscopic ultrasound (EUS)-guided transmural interventions, walled-off necrosis (WON) of the pancreas is increasingly managed via non-surgical endoscopic interventions. However, there has been an ongoing debate over the appropriate treatment strategy following the initial EUS-guided drainage. Direct endoscopic necrosectomy (DEN) removes intracavity necrotic tissue, potentially facilitating early resolution of the WON, but may associate with a high rate of adverse events. Given the increasing safety of DEN, we hypothesised that immediate DEN following EUS-guided drainage of WON might shorten the time to WON resolution compared to the drainage-oriented step-up approach. METHODS: The WONDER-01 trial is a multicentre, open-label, superiority, randomised controlled trial, which will enrol WON patients aged ≥ 18 years requiring EUS-guided treatment in 23 centres in Japan. This trial plans to enrol 70 patients who will be randomised at a 1:1 ratio to receive either the immediate DEN or drainage-oriented step-up approach (35 patients per arm). In the immediate DEN group, DEN will be initiated during (or within 72 h of) the EUS-guided drainage session. In the step-up approach group, drainage-based step-up treatment with on-demand DEN will be considered after 72-96 h observation. The primary endpoint is time to clinical success, which is defined as a decrease in a WON size to ≤ 3 cm and an improvement of inflammatory markers (i.e. body temperature, white blood cell count, and C-reactive protein). Secondary endpoints include technical success, adverse events including mortality, and recurrence of the WON. DISCUSSION: The WONDER-01 trial will investigate the efficacy and safety of immediate DEN compared to the step-up approach for WON patients receiving EUS-guided treatment. The findings will help us to establish new treatment standards for patients with symptomatic WON. TRIAL REGISTRATION: ClinicalTrials.gov NCT05451901, registered on 11 July 2022. UMIN000048310, registered on 7 July 2022. jRCT1032220055, registered on 1 May 2022.

Pancreatic fluid collections (PFCs) typically develop as local complications of acute pancreatitis and complicate the clinical course of patients with acute pancreatitis and potentially fatal clinical outcomes. Interventions are required in cases of symptomatic walled-off necrosis (WON) (matured PFCs with necrosis) and pancreatic pseudocysts (matured PFCs without necrosis). In the management of necrotizing pancreatitis and WON, endoscopic ultrasound-guided transluminal drainage combined with on-demand endoscopic necrosectomy (i.e. the step-up approach) is increasingly used as a less invasive treatment modality compared with a surgical or percutaneous approach. Through the substantial research efforts and development of specific devices and stents (e.g. lumen-apposing metal stents), endoscopic techniques of PFC management have been standardized to some extent. However, there has been no consensus about timing of carrying out each treatment step; for instance, it is uncertain when direct endoscopic necrosectomy should be initiated and finished and when a plastic or metal stent should be removed following clinical treatment success. Despite emerging evidence for the effectiveness of noninterventional supportive treatment (e.g. antibiotics, nutritional support, irrigation of the cavity), there has been only limited data on the timing of starting and stopping the treatment. Large studies are required to optimize the timing of those treatment options and improve clinical outcomes of patients with PFCs. In this review, we summarize the current available evidence on the indications and timing of interventional and supportive treatment modalities for this patient population and discussed clinical unmet needs that should be addressed in future research.

This study aimed to examine occupational radiation exposure to the lens of the eyes during endoscopic retrograde cholangiopancreatography (ERCP). In this multicenter, prospective, observational cohort study, we collected data regarding occupational radiation exposure to the lens of the eyes during ERCP. We measured radiation exposure of patients and examined its correlation with occupational exposure. In dosimetrically-measured ERCPs (n = 631), the median air kerma at the patient entrance reference point, air kerma-area product, and fluoroscopy time were 49.6 mGy, 13.5 Gycm2, and 10.9 min, respectively. The median estimated annual radiation dose to the lens of the eyes was 3.7, 2.2, and 2.4 mSv for operators, assistants, and nurses, respectively. Glass badge over lead aprons and eye dosimeter results were similar in operators but differed in assistants and nurses. A strong correlation was shown between eye dosimeter measurements and patients' radiation exposure. The shielding rates of the lead glasses were 44.6%, 66.3%, and 51.7% for operators, assistants, and nurses, respectively. This study revealed the actual occupational exposure dose for the lens of the eyes during ERCP and the efficacy of lead glass. Values of radiation exposure to patients can help estimate exposure to the lens of the eyes of medical staff.

BACKGROUND AND AIMS: Endoscopic ultrasound (EUS)-guided interventions currently serve as first-line treatment for symptomatic pancreatic fluid collections (PFCs) but require high-level expertise and multidisciplinary care. Hospital caseload has not been fully examined in relation to clinical outcomes of patients with endoscopically managed PFCs. METHODS: Using the Diagnosis Procedure Combination database, a Japanese nationwide inpatient database, we identified 4,053 patients receiving EUS-guided treatment of PFCs at 486 hospitals in 2010-2020 and examined an association of hospital volume (average annual number of cases at a hospital) with in-hospital mortality. Associations with bleeding, length of stay, and total costs were examined as secondary analyses. Multivariable logistic regression analysis was conducted with adjustment for potential confounders. RESULTS: The hospital volume was inversely associated with the risk of in-hospital mortality (Ptrend < .001). The adjusted odds ratio for in-hospital mortality comparing the extreme quintiles of hospital volume was 0.17 (95% confidence interval, 0.09-0.33). A restricted cubic spline analysis yielded no statistically significant evidence on the nonlinear relationship (Pnonlinearity = .19). The types of stents (plastic vs. lumen-apposing metal stent) appeared to have no effect modification on the volume-mortality relationship (Pinteraction = .58). Higher hospital volume was also associated with lower risk of bleeding, shorter length of stay, and lower medical costs of inpatient care. CONCLUSIONS: Higher hospital volume was associated with a lower risk of in-hospital mortality of patients receiving EUS-guided treatment of PFCs. A further investigation is warranted to justify the volume-based selective referral of the patients.

BACKGROUND: There is no consensus on the necessity of endoscopic sphincterotomy (ES) to prevent post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP) after endoscopic stenting in patients with malignant biliary obstruction. We investigated the incidence of PEP after endoscopic biliary stenting for malignant biliary obstruction with or without ES in a multicenter prospective cohort study. METHODS: We enrolled 807 patients who underwent endoscopic biliary stenting for malignant biliary obstruction with a native papilla at 36 hospitals between April 2017 and March 2018. The incidence of PEP in patients with or without ES was compared for subgroups based on stent type, placement method, and patient background. Univariate and multivariate analysis was performed to investigate the incidence of PEP in all stenting patients. RESULTS: Plastic and metal stents (MS) were inserted in 598 and 209 patients, respectively. The incidence of PEP in patients with or without ES was 7.9% and 7.4%, respectively among all stenting patients. The incidences of PEP with or without ES in plastic stent insertion patients, patients with MS insertion, stent insertions across the papilla, stent insertions across the papilla in patients without main pancreatic duct obstruction, and fully covered MS insertions across the papilla were compared. There was no overall significant difference in the incidence of PEP between those with or without ES. Multivariate logistic regression analysis for the incidence of PEP in all stenting patients revealed obstruction of the main pancreatic duct at the pancreatic head and epinephrine spraying on the papilla were significant factors; there was no significant difference in the incidence of PEP between patients with or without ES. CONCLUSION: Endoscopic sphincterotomy may not contribute to the prevention of PEP after endoscopic biliary stenting for malignant biliary obstruction, even in cases of insertion with a fully covered MS across the papilla.

OBJECTIVES: Interventions for necrotizing pancreatitis are generally postponed until 4 weeks after the onset of acute pancreatitis, but there remains controversy about whether we should always wait >4 weeks or can intervene early when necessary. This meta-analysis was conducted to evaluate treatment outcomes of necrotizing pancreatitis according to the cut-off defined in the revised Atlanta classification (≤4 vs. >4 weeks). METHODS: Using PubMed, Web of Science, and the Cochrane database, we identified clinical studies published until March 2022 with data comparing outcomes of early and delayed interventions of necrotizing pancreatitis. We pooled data on adverse events, mortality, technical and clinical success rates, and needs for necrosectomy and open surgery, using the random-effects model. RESULTS: We identified 11 retrospective studies, including 775 patients with early interventions and 725 patients with delayed interventions. Patients with early interventions tended to be complicated by organ failure. The rate of adverse events was comparable (OR 1.41, 95% CI 0.66-3.01; p = 0.38) but the rate of mortality was significantly higher (OR 1.70, 95% CI 1.21-2.40; p < 0.01) in early interventions. Technical success rates were similarly high but clinical success rates tended to be low (OR 0.39, 95% CI 0.15-1.00; p = 0.05) in early interventions, though not statistically significant. Pooled ORs for necrosectomy and open surgery were 2.14 and 1.23, respectively. CONCLUSIONS: Early interventions for necrotizing pancreatitis were associated with higher mortality rates and did not reduce adverse events or improve clinical success. However, our results should be confirmed in prospective studies.

OBJECTIVES: We surveyed and reported low protective equipment usage and insufficient knowledge among endoscopy-fluoroscopy departments in Japan in 2020. Two years later, we conducted a follow-up survey of doctors, nurses, and technologists in Japan. METHODS: We conducted a questionnaire survey on radiation protection from May to June 2022. The participants were medical staff, including doctors, nurses, and radiological and endoscopy technicians in endoscopy-fluoroscopy departments. The questionnaire included 17 multiple-choice questions divided into three parts: background, equipment, and knowledge. RESULTS: We surveyed 464 subjects from 34 institutions. There were 267 doctors (58%), 153 nurses (33%), and 44 technologists (9%). The rate of wearing a lead apron was 98% in this study. The rates of wearing a thyroid collar, lead glasses, and radiation dosimeter were 27%, 35%, and 74%, respectively. The trend of the protective equipment rate was similar to that of our previous study; however, radiation dosimetry among doctors was still low at 58%. The percentage of subjects who knew the radiation exposure (REX) dose of each procedure was low at 18%. Seventy-six percent of the subjects attended lectures on radiation protection, and 73% knew about the three principles of radiation protection; however, the concept of diagnostic reference levels was not well known (18%). Approximately 60% of the subjects knew about the exposure dose increasing cancer mortality (63%) and the 5-year lens REX limit (56%). CONCLUSIONS: There was some improvement in radiation protection equipment or education, but relatively little compared to the 2020 survey of endoscopy departments.

放射線透視下内視鏡手技における職業被ばくに関しては蓄積した放射線線量が健康被害に影響するため，手技に携わる医師は患者と自分自身だけでなく医療スタッフも保護するために最大限の努力を払う義務がある． ERCP関連手技に関しては，治療的ERCPが診断的ERCPよりも放射線被ばく線量が有意に多く，EUS-BDではERCPと比して，手技時間は有意に短かったにも関わらず使用放射線線量が有意に多かったことが報告されている． 放射線被ばく防護の3原則である“正当化”，“最適化”，“線量制限”，及び診断参考レベル：Diagnostic reference level（DRL）のコンセプトが理解され，自施設の透視装置に合わせた被ばく防護対策がとられ，放射線被ばくの低減を目的に日々進歩する技術が広く認識されることが求められる．

A 76-year-old woman presented with lower abdominal pain and nausea and was referred to the gastroenterology department in our institution. Previous contrast-enhanced computed tomography (CE-CT) for follow-up after breast cancer surgery had indicated a soft tissue mass below the right diaphragm, which was considered a benign change. CE-CT performed at the first visit to our department revealed further thickening of the soft tissue mass with extension to the liver surface. In addition, ascites and nodules were observed in the abdominal cavity. Histopathological examination of a biopsy specimen revealed peritoneal invasion of atypical epithelioid cells with trabecular and glandular patterns. The tumor cells were positive for AE1/AE2, calretinin, WT-1, D2-40, HEG1, EMA, BAP1, and MTAP and negative for carcinoembryonic antigen, MOC-31, Ber-Ep4, ER, PgR, TTF-1, claudin 4, and desmin. A diagnosis of epithelioid mesothelioma was made. The patient received chemotherapy with cisplatin (75 mg/m2) and pemetrexed (500 mg/m2). After six courses of combined chemotherapy, pemetrexed was administered as a single agent. At the time of writing this report, she was undergoing over the 30th course of chemotherapy without any significant side effects. Diffuse malignant peritoneal mesothelioma is a rare, fatal, and progressive disease. Our patient achieved long-term survival of more than 5 years with maintenance therapy using single-agent pemetrexed.

Pancreatic fluid collections (PFCs) commonly develop as complications of acute pancreatitis and ductal disruption due to chronic pancreatitis. In the revised Atlanta classification, PFCs were classified based on the presence of necrosis and duration following the onset of acute pancreatitis. Interventions are required in cases of symptomatic pancreatic pseudocysts or walled-off necrosis (WON). In the management of these PFCs, endoscopic ultrasound-guided transluminal drainage and subsequent direct endoscopic necrosectomy for WON are increasingly utilized as less invasive treatment modalities compared to surgical debridement. To date, researchers have focused predominantly on the technical aspects of endoscopic therapy for symptomatic PFCs. Given the poor physical condition of patients receiving endoscopic treatment for PFCs, systemic support may have a substantial impact on the short- and long-term outcomes of these patients. A multidisciplinary approach is required to improve the clinical outcomes of patients with infected PFCs and their associated comorbidities. However, non-interventional support during the periprocedural period of endoscopic treatment of PFCs has not been fully discussed, and there have been considerable variations in the selection of treatment options between endoscopists and centers. To address these unmet needs in the clinical management of PFCs and promote future research to improve the clinical outcomes, we conducted a review of the literature within a multicenter consortium of expert endoscopists with specific expertise in the endoscopic treatment of PFCs. In this review, we summarize the current evidence on non-interventional supportive care (e.g., continuous lavage, medications, nutritional support, and antimicrobials) and propose potential topics for future research.

BACKGROUND: The standard therapy for acute severe ulcerative colitis (ASUC) is intravenous corticosteroids; however, 30% of ulcerative colitis (UC) patients do not recover with corticosteroids alone. Few studies have reported the efficacy and safety of tofacitinib for ASUC with steroid resistance. We report a case series of successful first-line treatment consisting of tofacitinib (20 mg/day) administered to ASUC patients with steroid resistance. METHODS: Patients diagnosed with ASUC at our institution between October 2018 and February 2020 were retrospectively evaluated. They were administered a high dose of tofacitinib (20 mg) after showing no response to steroid therapy in a dose of 1-1.5 mg/kg/day. RESULTS: Eight patients with ASUC, 4 (50%) men, median age 47.1 (range 19-65) years, were included. Four patients were newly diagnosed, and the median UC duration was 4 (range 0-20) years. Six of the 8 patients were able to avoid colectomy. One patient (patient 2) had no response; however, remission was achieved after switching from tofacitinib to infliximab. One patient (patient 6) with no response to tofacitinib underwent total colectomy. Only one patient (patient 4) experienced an adverse event, local herpes zoster, treated with acyclovir without tofacitinib discontinuation. CONCLUSIONS: Clinical remission without serious adverse events can be achieved with high probability and colectomy can be avoided by first administering high-dose tofacitinib to steroid-resistant ASUC patients. Tofacitinib may be one of the first-line treatment options for steroid-resistant ASUC.

BACKGROUND AND OBJECTIVES: Although the use of a long metal stent is favored for EUS-guided hepaticogastrostomy (EUS-HGS) for the relief of malignant biliary obstruction (MBO), endoscopic reintervention (E-RI) at the time of recurrent biliary obstruction (RBO) is challenging due to a long intragastric portion. This study evaluated the feasibility and safety of E-RI after a long partially covered metal stent (L-PCMS) placement during EUS-HGS. MATERIALS AND METHODS: We performed a multicenter retrospective study between January 2015 and December 2019 examining patients with MBO who underwent E-RI for RBO through the EUS-HGS route after the L-PCMS placement. Technical and clinical success rates, details of E-RI, adverse events (AEs), stent patency, and survival time were evaluated. RESULTS: Thirty-three patients at eight referral centers in Japan who underwent E-RI through the EUS-HGS route were enrolled. The location of MBO was distal in 54.5%. The median intragastric length of the L-PCMS was 5 cm. As the first E-RI attempt, E-RI via the distal end of the existing L-PCMS was successful in 60.6%. The overall technical and clinical success rates of E-RI were 100% and 81.8%, respectively. Liver abscess was noted in one patient. A proximal biliary stricture was associated with the clinical ineffectiveness of E-RI in multivariable analysis (odds ratio, 12.5, P = 0.04). The median survival and stent patency duration after E-RI were 140 and 394 days, respectively. CONCLUSIONS: Our study findings suggest that E-RI for RBO after EUS-HGS with a L-PCMS is technically feasible and clinically effective, without any severe AEs, especially for patients with distal MBO.

BACKGROUND AND AIM: Endoscopic ultrasonography (EUS) findings of the pancreatic parenchyma, such as hyperechoic foci/stranding and lobularity, may be associated with the severity of chronic pancreatitis (CP). However, the correlation between parenchymal EUS findings and histology remains unclear. We designed a large-scale retrospective study analyzing over 200 surgical specimens to elucidate the association between parenchymal EUS findings and histological features. METHODS: Clinical data of 221 patients with pancreatobiliary tumors who underwent preoperative EUS and pancreatic surgery between January 2010 and November 2020 were reviewed to investigate the association between parenchymal EUS findings and histological features at the pancreatic body. None of these patients met the definition of CP. RESULTS: Of the 221 patients, 87 (39.4%), 89 (40.2%), and 45 (20.4%) had normal EUS findings, hyperechoic foci/stranding without lobularity, and hyperechoic foci/stranding with lobularity, respectively. In the multivariate analyses, parenchymal EUS findings significantly correlated with histological CP findings of fibrosis, inflammation, and atrophy (hyperechoic foci/stranding without lobularity vs hyperechoic foci/stranding with lobularity, odds ratio [95% confidence interval]: 4.1 [2.2-7.9] vs 31.3 [9.3-105.6], Ptrend  < 0.001; 3.9 [1.9-8.2] vs 21.8 [8.0-59.4], Ptrend  < 0.001; and 4.0 [2.0-7.8] vs 22.9 [7.0-74.5], Ptrend  < 0.001, respectively). Further, a trend toward higher histological grade was observed in the following order: normal findings, hyperechoic foci/stranding without lobularity, and hyperechoic foci/stranding with lobularity. CONCLUSIONS: Endoscopic ultrasonography findings of the pancreatic parenchyma may be associated with the histological conditions in CP, such as pancreatic fibrosis, inflammation, and atrophy. Lobularity reflects more severe histological conditions than does hyperechoic foci/stranding.

BACKGROUND: Treatments for patients with gastric outlet obstruction (GOO) due to unresectable pancreatic cancers (URPC) include gastrojejunostomy (GJJ) and endoscopic duodenal stent placement (EDSP). This study compared the efficacy and safety of GJJ and EDSP in patients with GOO due to URPC. METHODS: This study retrospectively evaluated consecutive patients with GOO due to URPC who underwent GJJ or EDSP between April 2016 and March 2020. The efficacy and safety of GJJ and EDSP were compared with propensity score analysis. Subgroup analyses of overall survival (OS) were compared after propensity matching. RESULTS: Data were obtained from 54 patients who underwent GJJ and from 73 who underwent EDSP at five tertiary care hospitals. After propensity matching, OS was significantly longer in patients who underwent GJJ than EDSP (110 vs. 63 days, respectively; p = 0.019). Evaluation of long-term adverse events showed that the frequency of cholangitis and obstructive jaundice was significantly lower in the matched GJJ than in the matched EDSP group (p = 0.012). Subgroup analyses showed that OS in patients with good performance status (PS; p = 0.041), biliary obstruction (p = 0.007), and duodenal obstruction near the papilla (p = 0.027), and those receiving chemotherapy (p = 0.010), was significantly longer in the matched GJJ group than in matched EDSP group. CONCLUSION: GJJ provides longer OS than EDSP for patients with GOO caused by URPC, especially for patients with good PS, biliary obstruction, and duodenal obstruction near the papilla, and those receiving chemotherapy.

BACKGROUND: The appropriate method of preoperative endoscopic biliary drainage (EBD) for cholangiocarcinoma with hilar biliary obstruction remains controversial. The inside-stent technique is a method of placing plastic stents entirely inside the bile duct. Several studies of patients with unresectable stage have reported longer stent patency compared with conventional endoscopic biliary stenting (EBS). Inside-stent techniques have been introduced as a bridge-to-surgery option and as an alternative to conventional EBS. AIMS: We aimed to evaluate the clinical outcomes of inside stent use and conventional EBS. METHODS: During this retrospective multicenter study, we reviewed consecutive patients with cholangiocarcinoma who underwent radical surgery after conventional EBS or inside-stent insertion. Adverse event (AE) rates after EBD and post-surgical AEs were compared. A multivariable analysis was performed to identify factors affecting cholangitis after EBD. RESULTS: Conventional EBS and inside-stent procedures were performed for 56 and 73 patients, respectively. Patient backgrounds were similar between groups, except for percutaneous transhepatic portal vein embolization. The waiting time before surgery was similar between groups (28.5 days vs. 30 days). There were no significant differences in the cholangitis rate (21.4% vs. 26.0%; P = 0.68) and all AEs (25.0% vs. 30.1%; P = 0.56) between groups. The post-surgical AE rate was similar between the groups. The multivariable analysis found that preprocedural cholangitis was a risk factor for cholangitis after EBD (odds ratio: 5.67; 95% confidence interval: 1.61-19.9). CONCLUSIONS: The outcomes of inside-stent techniques and conventional EBS for the management of preoperative EBD are comparable for patients with cholangiocarcinoma.

The double-guidewire method has been increasingly used in endoscopic procedures for biliary and pancreatic diseases in recent years, including endoscopic retrograde cholangiopancreatography and endoscopic ultrasonography-related procedures. In addition, double-lumen catheters with uneven distal and proximal lumen openings have been introduced, making it possible to easily create a double-guidewire situation, and the usefulness of the double-guidewire technique using uneven double-lumen cannulas has been widely reported. Although the advantages of using two guidewires depend on the particular situation and the appropriate use of the two guidewires, deepening the knowledge of the double-guidewire method will contribute greatly to troubleshooting in daily practice. In this review, the usefulness of the double-guidewire technique is discussed with respect to two main areas: selective insertion of guidewires and devices and biliary cannulation.

Background Pancreatic neuroendocrine carcinoma (PanNEC) is a rare disease entity with rapid progression and poor prognosis. Here, we report a PanNEC case with unique morphological features mimicking intraductal papillary mucinous carcinoma. Case presentation A 69-year-old Japanese man was referred to our hospital for further evaluation of weight loss and deterioration of diabetes mellitus. Contrast-enhanced computed tomography showed a solid and cystic mass with hypo-enhancement at the tail of the pancreas. The main pancreatic duct (MPD) was diffusely dilated without obstruction, accompanied by marked parenchymal atrophy. Multiple peritoneal and omental nodules were observed, suggesting tumor dissemination. Endoscopic retrograde cholangiopancreatography revealed that the mass correlated with the dilated MPD. During pancreatography, a large amount of mucus was extruded from the pancreatic orifice of the ampulla. Based on these imaging findings, intraductal papillary mucinous carcinoma was suspected. Per-oral pancreatoscopy (POPS)-guided tumor biopsies were conducted for the lesion's solid components. Histopathological examination of the biopsied material confirmed small-cell-type PanNEC with a Ki-67 labeling index of 90%. Due to his condition's rapid decline, the patient was given the best supportive care and died 28 days after diagnosis. Conclusion Although rare, PanNEC, which correlates with the MPD and is accompanied by marked dilation of the MPD, does exist as one phenotype. In such cases, POPS-guided biopsy could be a useful diagnostic modality.

Background/Aims: Bispectral index (BIS) monitors process and display electroencephalographic data and are used to assess the depth of anesthesia. This study retrospectively evaluated the usefulness of BIS monitoring during endoscopic ultrasonography (EUS). Methods: This study included 725 consecutive patients who underwent EUS under sedation with propofol. BIS monitoring was used in 364 patients and was not used in 361. The following parameters were evaluated: (1) median dose of propofol; (2) respiratory and circulatory depression; (3) occurrence of body movements; (4) awakening score >8 at the time; and (5) awakening score 2 hours after leaving the endoscopy room. Results: The BIS group received a significantly lower median dose of propofol than the non-BIS group (159.2 mg vs. 167.5 mg; p=0.015) in all age groups. For patients aged ≥75 years, the reduction in heart rate was significantly lower in the BIS group than in the non-BIS group (1.2% vs. 9.1%; p=0.023). Moreover, the occurrence of body movements was markedly lower in the BIS group than in the non-BIS group (8.5% vs. 39.4%; p<0.001). Conclusions: During EUS examination, BIS monitoring is useful for maintaining a constant depth of anesthesia, especially in patients 75 years of age or older.

Background: The value of contrast-enhanced harmonic EUS (CH-EUS) for diagnosis of portal vein invasion in patients with pancreatic cancer was evaluated. Patients and Methods: This single-center, retrospective study included consecutive patients with pancreatic cancer who underwent both surgical resection after preoperative EUS, CH-EUS, and contrast-enhanced computed tomography (CE-CT) examinations between April 2015 and August 2017. CH-EUS evaluation was performed during the late phase. Portal vein invasion on EUS and CH-EUS was defined as no continuity in the line of the vessel wall. Definition of portal vein invasion on CE-CT was based on the Loyer's criteria. The accuracy of three modalities for diagnosis of invasion into the portal vein was compared using the McNemar's test. Results: Eighty-eight patients (mean age: 71.0 years, ratio of male to female: 48:40) were eligible. Postoperative pathological results were as follows: seven cases of portal vein invasion; 81 cases without. Diagnostic accuracy of EUS, CH-EUS, and CE-CT for diagnosing invasion into the portal vein was 72.7%, 93.2%, and 81.8%, respectively. The differences between CH-EUS and CE-CT (P = 0.0094) and CH-EUS and EUS (P = 0.0022) were significant. EUS and CE-CT were comparable. Conclusion: CH-EUS is useful for diagnosis of portal vein invasion by pancreatic cancer.

INTRODUCTION: Endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) is a novel drainage option for patients with an inaccessible papilla. Although EUS-HGS has clinical benefits in patients for whom endoscopic retrograde cholangiopancreatography (ERCP) has failed, the rates of adverse events (AEs) associated with EUS-HGS, such as bile peritonitis and stent migration, are higher than for other procedures. The development of a dedicated system for EUS-HGS is therefore desirable to reduce the rate of AEs. We developed a dedicated system for EUS-HGS (HG01 system) which is composed of a 19-gauge needle, 0.025-inch guidewire, a thin delivery system for tract dilation, and an antimigration metal stent. This study is designed to evaluate the efficacy and safety of EUS-HGS using the HG01 system in malignant biliary obstruction. METHODS/DESIGN: This is a single-arm multicenter prospective study involving 40 patients across six tertiary centers in Japan. Patients with an unresectable malignant biliary obstruction in whom biliary drainage with ERCP failed, is not possible, or is very difficult will be registered in the study. The primary endpoint is the clinical success rate. The secondary endpoints are the technical success rate, procedure-related AE rate, procedure time, procedure success rate using only the HG01 system, stent patency rate, re-intervention success rate, re-intervention method, survival rate, and distance of movement of the stent position. DISCUSSION: We expect use of the HG01 system to reduce the rate of AEs during EUS-HGS, especially bile leakage and stent migration. If the efficacy and safety of EUS-HGS using the HG01 system is confirmed in the present study, it is likely to be considered the first-choice device for use during EUS-HGS.

OBJECTIVES: Endoscopic ultrasound-guided tissue acquisition (EUS-TA) plays a crucial role in the diagnosis of pancreatic tumors. The present study aimed to investigate the current status of needle tract seeding (NTS) after EUS-TA of pancreatic tumors based on a nationwide survey in Japan. METHODS: Patients who underwent surgical resection of primary pancreatic tumors after EUS-TA performed between April 2010 and March 2018 were surveyed. The incidence rates of NTS were determined, and compared in patients with pancreatic ductal adenocarcinomas (PDACs) and other tumors, and in patients who underwent transgastric and transduodenal EUS-TA of PDACs. The detailed features and prognosis of patients with NTS were also assessed. RESULTS: A total of 12,109 patients underwent surgical resection of primary pancreatic tumors after EUS-TA. The overall incidence rate of NTS was 0.330%, and the NTS rate was significantly higher in patients with PDAC than in those with other tumors (0.409% vs. 0.071%, P=0.004). NTS was observed in 0.857% of patients who underwent transgastric EUS-TA, but in none of those who underwent transduodenal EUS-TA. Of the patients with NTS of PDACs, the median time from EUS-TA to occurrence of NTS and median patient survival were 19.3 and 44.7 months, respectively, with 97.4% of NTS located in the gastric wall and 65.8% of NTS resected. The patient survival was significantly longer in patients who underwent NTS resection than in those without NTS resection (P=0.037). CONCLUSIONS: NTS appeared only after transgastric not after transduodenal EUS-TA. Careful follow-up provides an opportunity to remove localized NTS lesions by gastrectomy.

Video 1A novel training method for endoscopic ultrasound operators, the Educational Program of Kindai system enables visualization of a trainee's learning curve and difficult-to-learn areas. This visualization helps both the trainer and the trainee to structure learning and teaching methods in real time.

PURPOSE: To compare image quality and the detectability of gallstones in patients with T1 hyperintense bile between single breath-hold three-dimensional (3D) magnetic resonance cholangiopancreatography (MRCP) with gradient and spin-echo (GRASE) and with compressed sensing (CS). METHODS: We retrospectively evaluated patients who underwent MRCP using GRASE and CS and had hyperintense bile on T1-weighted fat-suppressed images. The relative duct-to-periductal contrast ratios (RCs) of each bile duct segment were calculated. Pancreaticobiliary duct visibility, motion artifacts, background suppression, and overall image quality were scored on a 5-point scale. The Wilcoxon signed-rank test was used to analyze differences in qualitative and quantitative results. Diagnostic performance in detecting common bile duct (CBD) and gallbladder stones was assessed using receiver operating characteristic (ROC) curves. RESULTS: In total, 96 patients were included in the study. RCs of all bile duct segments in GRASE MRCP were significantly lower than those in CS MRCP (p < 0.001). All biliary duct visibility and overall image quality had significantly higher scores in GRASE MRCP than in CS MRCP (p < 0.001-0.003). Area under ROC curves of GRASE MRCP and CS MRCP were 1.00 and 0.88 for CBD stone (p = 0.14) and 0.93 and 0.82 for gallbladder stone (p = 0.08), respectively. CONCLUSIONS: GRASE MRCP provides better image quality than CS MRCP in patients with hyperintense bile on T1-weighted images. The detectability of biliary stones was also higher in GRASE MRCP than in CS MRCP, although not significantly.

OBJECTIVES: This study evaluated the efficacy of endoscopic ultrasound-guided celiac plexus neurolysis (EUS-CPN) in combination with EUS-guided celiac ganglia neurolysis (EUS-CGN) for pancreatic cancer-associated pain. METHODS: This multicenter prospective trial was registered in the University Hospital Medical Information Network (UMIN000031228). Fifty-one consecutive patients with pancreatic cancer-associated pain who presented at one of five Japanese referral centers between February 2018 and March 2021 were enrolled. EUS-CGN was added in cases of visible celiac ganglia. The primary endpoint was effectiveness, defined as a decrease in the numerical rating scale (NRS) by ≥ 3 points. NRS data were prospectively acquired at 1 week after the procedure to evaluate its effectiveness and the extent of pain relief. RESULTS: The technical success rates of EUS-CPN and EUS-CGN were 100% and 80.4%, respectively. The overall efficacy rate was 82.4% [90% confidence interval (CI) 71.2-90.5, P < 0.0001]. The complete pain relief rate was 27.4%. The adverse events rate was 15.7%. The average pain relief period was 72 days. The efficacy rate was higher in the EUS-CPN plus EUS-CGN group than in the EUS-CPN alone group. EUS-CPN plus EUS-CGN was superior to EUS-CPN alone for achieving complete pain relief (P = 0.045). EUS-CGN did not improve the average length of the pain relief period. CONCLUSIONS: EUS-CPN combined with EUS-CGN is safe, feasible, and effective for pain relief in patients with pancreatic cancer. The patients who received additional EUS-CGN had a better short-term response. CLINICAL TRIAL NUMBER: UMIN000031228.

急性胆管炎の死亡率は2.7％と報告され，初期対応を誤れば致死的な経過となる可能性がある病態である．急性胆管炎・胆囊炎診療ガイドライン2018（Tokyo Guidelines 18）には重症度別の急性胆管炎治療が記載されているが，中等症もしくは重症と診断される急性胆管炎には，緊急胆道ドレナージが推奨される．ドレナージ方法にはendoscopic biliary drainage，percutaneous transhepatic biliary drainageがあり，症例に応じた選択が求められる．今後デバイスの改良によりEUS-guided biliary drainageが代替え治療になる可能性はあるが，どのドレナージを選択したとしても，それぞれの特徴，長所・短所，手技内容を十分に理解した上で慎重に行うことには変わりはない．

Objectives: The endoscopic bilateral stent-in-stent (SIS) deployment is a challenging procedure. Such difficulty is mainly caused by sticking of the tip of the delivery sheath into the self-expandable metal stents (SEMSs) mesh, requiring an additional dilating procedure. Herein, we assessed the clinical results of using cross-wired metal stent for endoscopic bilateral SIS deployment (BONASTENT M-Hilar) in patients with malignant hilar biliary obstruction (MHBO) in both high-volume and non-high-volume centers. Methods: We prospectively enrolled consecutive patients with MHBO between February 2016 and December 2018 at eight centers. Results: Forty-six patients were enrolled during the study period. The proportions of technical success were 93.5% (43/46) and clinical success (CS) on intention-to-treat and per-protocol analyses were 91.3% (42/46) and 93.0% (40/43), respectively. The proportion of an additional dilating procedure during the primary procedure was 50.0% (23/46). Recurrent biliary obstruction (RBO) on intention-to-treat analysis occurred in 32.6% (15/46) of cases. Almost all of the events were caused by stent ingrowth (14/15). The median survival time and time to RBO were 255 and 349 days, respectively. The probability of stent patency at 3, 6, and 12 months was 86.5%, 63.9%, and 47.6%, respectively. Conclusions: The cross-wired metal stent had excellent technical and CS, although non-high-volume centers were included in this study (UMIN000021441).

Fluoroscopy forms an essential part of endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) and hepaticogastrostomy with antegrade stenting (EUS-HGAS). To date, no study has assessed and compared radiation exposure between EUS-HGS and EUS-HGAS. This study aimed to compare the radiation exposure parameters between EUS-HGS and EUS-HGAS. This retrospective single-center cohort study included consecutive patients who underwent EUS-HGS or EUS-HGAS from October 2017 to March 2019. The air kerma (AK: mGy), kerma-area product (KAP: Gycm2), fluoroscopy time (FT: min), and procedure time (PT: min) were assessed and compared between the two procedures. Altogether, 45 and 24 patients underwent EUS-HGS and EUS-HGAS, respectively. The median AK, KAP, FT, and PT were higher in the EUS-HGAS group than in the EUS-HGS group. A comparison revealed no difference in the technical success rate, complications rate, adverse event occurrence rate, and re-intervention rate between both procedures. This is the first report in which radiation exposure was used as a comparative parameter between EUS-HGS and EUS-HGAS. This study revealed that radiation exposure is significantly higher in EUS-HGAS than in EUS-HGS. Increased awareness on radiation exposure is warranted among gastroenterologists so that they choose the procedure with lower radiation exposure in cases where both procedures are indicated.

BACKGROUND: Diagnostic reference levels (DRLs) are required to optimize medical exposure. However, data on DRLs for interventional fluoroscopic procedures are lacking, especially in gastroenterology. This study aimed to prospectively collect currently used radiation doses and help establish national DRLs for fluoroscopy-guided gastrointestinal procedures in Japan. METHODS: This multicentre, prospective, observational study collected actual radiation dose data from endoscopic retrograde cholangiopancreatography (ERCP), interventional endoscopic ultrasound (EUS), balloon-assisted enteroscopy (BAE), enteral metallic stent placement, and enteral tube placement from May 2019 to December 2020. The study outcomes were fluoroscopy time (FT: min), air kerma at the patient entrance reference point (Ka,r: mGy), air kerma area product (PKA: Gycm2), and radiation dose rate (RDR: mGy/min). Additionally, the basic settings of fluoroscopy equipment and the factors related to each procedure were investigated. This study was registered in the UMIN Clinical Trial Registry (UMIN 000036525). FINDINGS: Overall, 12959 fluoroscopy-guided gastrointestinal procedures were included from 23 hospitals in Japan. For 11162 ERCPs, the median/third quartile values of Ka,r (mGy), PKA (Gycm2), and FT (min) were 69/145 mGy, 16/32 Gycm2, and 11/20 min, respectively. Similarly, these values were 106/219 mGy, 23/41 Gycm2 and 17/27 min for 374 interventional EUSs; 53/104 mGy, 16/32 Gycm2 and 10/15 min for 523 metallic stents; 56/104 mGy, 28/47 Gycm2, and 12/18 min for 599 tube placements; and 35/81 mGy, 16/43 Gycm2 and 7/15 min for 301 BAEs, respectively. For the overall radiation dose rate, the median/third quartile values of RDR were 5.9/9.4 (mGy/min). The RDR values at each institution varied widely. INTERPRETATION: This study reports the current radiation doses of fluoroscopy-guided gastrointestinal procedures expressed as DRL quantities. This will serve as a valuable reference for national DRL values. FUNDING: This work was supported by a clinical research grant from the Japanese Society of Gastroenterology.

Drainage therapy for malignant biliary obstruction (MBO) includes trans-papillary endoscopic retrograde biliary drainage (ERBD), percutaneous transhepatic biliary drainage (PTBD), and trans-gastrointestinal endoscopic ultrasound-guided biliary drainage (EUS-BD). With the development of chemotherapy, many MBO cases end up needing endoscopic reintervention (E-RI) for recurrent biliary obstruction. To achieve a successful E-RI, it is necessary to understand the various findings regarding E-RI in MBO cases reported to date. Therefore, in this review, we focus on E-RI for ERBD of distal MBO, ERBD of hilar MBO, and EUS-BD. To plan an appropriate E-RI strategy for biliary stent occlusion for MBO, the following must be considered on a case-by-case basis: the urgency of the drainage, the cause of the occlusion, the original route of drainage (PTBD/ERBD/EUS-BD), the initial stent used (plastic stent or self-expandable metallic stent), and in the case of self-expandable metallic stents, the type used (fully covered or uncovered). Regardless of the original method of stent placement, if the inflammation caused by obstructive cholangitis is severe and/or the patient is in shock, PTBD should be considered as the first choice. Finally, it is important to keep in mind that in many cases, performing E-RI will be difficult.

BACKGROUND AND AIMS: This large multicenter randomized controlled trial compared the diagnostic yields of 22-gauge standard and 22-gauge Franseen needles for EUS-guided tissue acquisition (EUS-TA) of solid pancreatic lesions. METHODS: Consecutive patients with solid pancreatic lesions were prospectively randomized to EUS-TA using standard or Franseen needles. Samples obtained with the first needle pass and with second and subsequent passes were evaluated separately. The primary endpoint was the rate of accuracy for diagnosis of malignancy. Other endpoints were technical success rate, sample cellularity, adverse events, diagnostic accuracy in patient subgroups, and the diagnostic accuracy and numbers of second and subsequent needle passes. RESULTS: Of 523 patients undergoing EUS-TA, 260 were randomized to using standard 22-gauge needles and 263 to 22-gauge Franseen needles. The technical success rate in each group was 99.6%, with similar adverse event rates in the standard (1.5%) and Franseen (.8%) needle groups. First-pass EUS-TA using the Franseen needle resulted in significantly greater diagnostic accuracy (84.0% vs 71.2%, P < .001) and sensitivity (82.4% vs 66.7%, P < .001) than first-pass EUS-TA using a standard needle and also resulted in superior diagnostic accuracy in patients requiring immunostaining. Second and subsequent EUS-TA using Franseen needles showed significantly greater accuracy (94.7% vs 90.0%, P = .049) and sensitivity (94.0% vs 88.6%, P = .047) and required fewer needle passes (1.81 vs 2.03, P = .008) than using standard needles. CONCLUSIONS: EUS-TA with the Franseen needle is superior to EUS-TA with a standard needle with respect to diagnostic accuracy per pass, particularly in patients who require immunostaining, and number of passes when using macroscopic on-site evaluation. (Clinical trial registration numbers: UMIN000030634 and jRCTs052180062.).

BACKGROUND AND AIM: Contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) is useful for the diagnosis of lesions inside and outside the digestive tract. This study evaluated the value of artificial intelligence (AI) in the diagnosis of gastric submucosal tumors by CH-EUS. METHODS: This retrospective study included 53 patients with gastrointestinal stromal tumors (GISTs) and leiomyomas, all of whom underwent CH-EUS between June 2015 and February 2020. A novel technology, SiamMask, was used to track and trim the lesions in CH-EUS videos. CH-EUS was evaluated by AI using deep learning involving a residual neural network and leave-one-out cross-validation. The diagnostic accuracy of AI in discriminating between GISTs and leiomyomas was assessed and compared with that of blind reading by two expert endosonographers. RESULTS: Of the 53 patients, 42 had GISTs and 11 had leiomyomas. Mean tumor size was 26.4 mm. The consistency rate of the segment range of the tumor image extracted by SiamMask and marked by the endosonographer was 96% with a Dice coefficient. The sensitivity, specificity, and accuracy of AI in diagnosing GIST were 90.5%, 90.9%, and 90.6%, respectively, whereas those of blind reading were 90.5%, 81.8%, and 88.7%, respectively (P = 0.683). The κ coefficient between the two reviewers was 0.713. CONCLUSIONS: The diagnostic ability of CH-EUS results evaluated by AI to distinguish between GISTs and leiomyomas was comparable with that of blind reading by expert endosonographers.

【背景と目的】EUS-FNAは，様々な種類の消化器疾患の病理組織学的診断に用いられている．EUS-FNAによる有害事象がいくつか報告されているが，実際の有害事象の発生に関する実態は不明である．本研究の目的は，病理組織学的診断目的のEUS-FNAに関連する有害事象が発生した症例の現状を明らかにすることである． 【方法】日本の三次医療機関におけるEUS-FNA関連有害事象症例について，臨床データ（基本患者情報，FNAの手技，EUS-FNA関連有害事象の種類，予後など）を後ろ向きに解析した． 【結果】全EUS-FNA症例13,566例のうち，EUS-FNA関連有害事象が発生した合計症例数は234例であった．EUS-FNA関連有害事象の発生率は約1.7％であった．出血症例と膵炎症例が全有害事象のそれぞれ約49.1％と26.5％を占めた．最も一般的な有害事象は出血で，輸血を必要としたのは７例のみであった．神経内分泌腫瘍症例で最も頻度の高かった有害事象は膵炎であった．観察期間中，EUS-FNAによるneedle tract seedingが認められたのは，膵癌症例のわずか約0.1％であった．EUS-FNA関連有害事象による死亡は認められなかった． 【結論】本研究により，病理組織学的診断目的のEUS-FNAに関連する有害事象は，発生率が低く，重症例も少ないことが明らかとなった．

【目的】改正された電離放射線障害防止規則（2020年4月）では，眼の水晶体の等価線量限度が「5年で100 mSv，なおかつ1年で50 mSv」に引き下げられた．医療部門での職業被ばくを減らす必要がある．この研究の目的は，X線診療室での散乱線量を個人線量当量として測定し，内視鏡的逆行性胆管膵管造影（ERCP）検査における等価線量限度との比較を容易にすることである．【方法】散乱線量は，X線診療室に格子状に配置された放射線測定器によって測定した．線量率は，X線管の周りから患者まで伸びる防護クロス（0.25 mm Pb当量）を使用した場合としない場合で測定した．【結果】ERCPを実施する術者の立ち位置での最大線量率は，地面から150 cmで2.9 mSv/h（3 mm線量当量率）であった．防護クロスを使用しない場合の眼の水晶体の等価線量限度を遵守するためのERCP件数は28件/年であった．【結語】本研究結果はX線診療室内の個人線量当量測定が眼の水晶体の等価線量限度との比較を容易にする可能性を示唆した．

膵管にガイドワイヤーを留置し，乳頭を固定し，胆管末端部の直線化を図って胆管挿管を行う，膵管ガイドワイヤー留置法（PGW法：Pancreatic guidewire法）は挿管困難症例に対するオプションとして臨床の現場で広く用いられている．一方でPGW法を用いても胆管挿管に難渋する症例はよく経験され，“膵管にガイドワイヤーが留置されることで乳頭そのものの可動性を抑えることは少し可能になるが，屈曲の強い乳頭内胆管が完全に直線化しない可能性も十分にあり得る”ことを念頭に胆管挿管に向き合う必要がある．PGW法はあくまでもオプションの一つであり，胆管挿管の成功は膵管ガイドワイヤー留置後の，対峙した乳頭の形態，口側隆起の形状，その症例でとり得るスコープポジション，を踏まえた挿管ストラテジーの構築なくしてはなし得ない．術後膵炎のリスクを常に想定しながら，安全・確実な膵管ガイドワイヤー留置，症例に応じた各種挿管手法の使い分けを，論理的に，かつ愛護的に操る必要がある．

BACKGROUND AND OBJECTIVES: Although the use of a long metal stent is favored for EUS-guided hepaticogastrostomy (EUS-HGS) for the relief of malignant biliary obstruction (MBO), endoscopic reintervention (E-RI) at the time of recurrent biliary obstruction (RBO) is challenging due to a long intragastric portion. This study evaluated the feasibility and safety of E-RI after a long partially covered metal stent (L-PCMS) placement during EUS-HGS. MATERIALS AND METHODS: We performed a multicenter retrospective study between January 2015 and December 2019 examining patients with MBO who underwent E-RI for RBO through the EUS-HGS route after the L-PCMS placement. Technical and clinical success rates, details of E-RI, adverse events (AEs), stent patency, and survival time were evaluated. RESULTS: Thirty-three patients at eight referral centers in Japan who underwent E-RI through the EUS-HGS route were enrolled. The location of MBO was distal in 54.5%. The median intragastric length of the L-PCMS was 5 cm. As the first E-RI attempt, E-RI via the distal end of the existing L-PCMS was successful in 60.6%. The overall technical and clinical success rates of E-RI were 100% and 81.8%, respectively. Liver abscess was noted in one patient. A proximal biliary stricture was associated with the clinical ineffectiveness of E-RI in multivariable analysis (odds ratio, 12.5, P = 0.04). The median survival and stent patency duration after E-RI were 140 and 394 days, respectively. CONCLUSIONS: Our study findings suggest that E-RI for RBO after EUS-HGS with a L-PCMS is technically feasible and clinically effective, without any severe AEs, especially for patients with distal MBO.

OBJECTIVES: The reported incidence of adverse events (AEs) in endoscopic retrograde cholangiopancreatography (ERCP) varies between 2.5% and 14%. The aim of this study was to evaluate the incidence and severity of AEs in biliary ERCP and to specify the risk factors and preventive measures for post-ERCP pancreatitis (PEP). METHODS: Patients with biliary disease with intact papilla were prospectively enrolled at 36 hospitals between April 2017 and March 2018. The primary outcomes were the incidence and severity of AEs. RESULTS: A total of 16,032 ERCP procedures were performed at the 36 hospitals during the study period and 3739 patients were enrolled. The overall incidence of AEs was 10.1% and ERCP-related mortality was 0.08%. PEP developed in 258 cases (6.9%), bleeding in 33 (0.9%), instrumental AEs in 17 (0.5%), infections in 37 (1.0%), cardiovascular AEs in eight (0.2%), pulmonary AEs in eight (0.2%), drug reaction AE in one (0.03%), pain in 15 (0.4%), and other AEs in 15 (0.4%). Multivariable analysis showed significant risk factors for PEP were: female of younger age, pancreatic guidewire-assisted biliary cannulation, temporary guidewire insertion into the pancreatic duct, total procedure time >60 min, and post-ERCP administration of non-steroidal anti-inflammatory drugs. Effective preventive measures were prophylactic pancreatic stenting (PPS) and epinephrine spraying onto the papilla. CONCLUSIONS: In patients with intact papilla who underwent biliary ERCP, the incidence of AEs was 10.1% and the mortality was 0.08%. PPS and epinephrine spraying may prevent PEP. REGISTRATION: This study was registered in the University Hospital Medical Information Network (UMIN000024820).

Fluoroscopy-guided endoscopic procedures (FGEPs) are rapidly gaining popularity in the field of gastroenterology. Radiation is a well-known health hazard. Gastroenterologists who perform FGEPs are required to protect themselves, patients, as well as nurses and radiologists engaged in examinations from radiation exposure. To achieve this, all gastroenterologists must first understand and adhere to the International Commission on Radiological Protection Publication. In particular, it is necessary to understand the three principles of radiation protection (Justification, Optimization, and Dose Limits), the As Low As Reasonably Achievable principle, and the Diagnostic Reference Levels (DRLs) according to them. This review will mainly explain the three principles of radiation exposure protection, DRLs, and occupational radiological protection in interventional procedures while introducing related findings. Gastroenterologists must gain knowledge of radiation exposure protection and keep it updated.

BACKGROUND: Pancreatic cancer (PC) exhibits extremely rapid growth; however, it remains largely unknown whether the early stages of PC also exhibit rapid growth speed equivalent to advanced PC. This study aimed to investigate the natural history of early PCs through retrospectively assessing pre-diagnostic images. METHODS: We examined the data of nine patients, including three patients with carcinoma in situ (CIS), who had undergone magnetic resonance cholangiopancreatography (MRCP) to detect solitary main pancreatic duct (MPD) stenosis >1 year before definitive PC diagnosis. We retrospectively analyzed the time to diagnosis and first-time tumor detection from the estimated time point of first-time MPD stenosis detection without tumor lesion. RESULTS: The median tumor size at diagnosis and the first-time tumor detection size were 14 and 7.5 mm, respectively. The median time to diagnosis and first-time tumor detection were 26 and 49 months, respectively. CONCLUSIONS: No studies have investigated the PC history, especially that of early PCs, including CIS, based on the initial detection of MPD stenosis using MRCP. Assessment of a small number of patients showed that the time to progression can take several years in the early PC stages. Understanding this natural history is very important in the clinical setting.

Positron emission tomography (PET-CT) is an essential imaging modality for the management of various diseases. Increasing numbers of PET-CT examinations are carried out across the world and deliver benefits to patients; however, there are concerns about the cumulative radiation doses from these examinations in patients. Compared to the radiation exposure delivered by CT, there have been few reports on the frequency of patients with a cumulative effective radiation dose of ≥100 mSv from repeated PET-CT examinations. The emerging dose tracking system facilitates surveys on patient cumulative doses by PET-CT because it can easily wrap up exposure doses of PET radiopharmaceuticals and CT. Regardless of the use of a dose tracking system, implementation of justification for PET-CT examinations and utilisation of dose reduction measures are key issues in coping with the cumulative dose in patients. Despite all the advantages of PET/MRI such as eliminating radiation exposure from CT and providing good tissue contrast in MRI, it is expensive and cannot be introduced at every facility; thus, it is still necessary to utilise PET-CT with radiation reduction measures in most clinical situations.

Although many interventions involving radiation exposure have been replaced to endoscopic procedure in the gastrointestinal and hepatobiliary fields, there remains no alternative for enteroscopy and endoscopic retrograde cholangiopancreatography (ERCP), which requires the use of radiation. In this review, we discuss the radiation doses and protective measures of endoscopic procedures, especially for ERCP. For the patient radiation dose, the average dose area product for diagnostic ERCP was 14-26 Gy.cm², while it increased to as high as 67-89 Gy.cm² for therapeutic ERCP. The corresponding entrance skin doses for diagnostic and therapeutic ERCP were 90 and 250 mGy, respectively. The mean effective doses were 3- 6 mSv for diagnostic ERCP and 12-20 mSv for therapeutic ERCP. For the occupational radiation dose, the typical doses were 94 μGy and 75 μGy for the eye and neck, respectively. However, with an over-couch-type X-ray unit, the eye and neck doses reached as high as 550 and 450 μGy, with maximal doses of up to 2.8 and 2.4 mGy/procedure, respectively.A protective lead shield was effective for an over couch X-ray tube unit. It lowered scattered radiation by up to 89.1% in a phantom study. In actual measurements, the radiation exposure of the endoscopist closest to the unit was reduced to approximately 12%. In conclusion, there is a clear need for raising awareness among medical personnel involved endoscopic procedures to minimise radiation risks to both the patients and staff.

BACKGROUND: Disconnected pancreatic duct syndrome (DPDS) frequently occurs in patients with acute necrotizing pancreatitis and resultant pancreatic fluid collection (PFC). We performed a systematic review and meta-analysis to evaluate outcomes of endoscopic ultrasound-guided treatment of PFCs according to the presence of DPDS. METHODS: Using PubMed, Embase, and the Cochrane database, we identified clinical studies published until January 2021 with data comparing outcomes of endoscopic ultrasound-guided drainage of PFCs between DPDS and non-DPDS patients. We pooled data on technical and clinical success rates, PFC recurrence, and adverse events using the random-effects model. RESULTS: We identified five eligible articles including 941 PFC patients treated with endoscopic ultrasound-guided interventions. Clinical success, defined as resolution of the PFC and symptoms, was achieved in a majority of the cases irrespective of DPDS (pooled odds ratio [OR] comparing DPDS to non-DPDS patients, 0.77; 95% confidence interval [CI], 0.33-1.81). Compared to patients without DPDS, patients with DPDS were more likely to undergo PFC recurrence (pooled OR, 6.72; 95% CI, 2.72-16.6) after clinical resolution of PFC. Prolonged plastic stent placement following the clinical resolution was more frequently performed in DPDS patients than in non-DPDS patients (pooled OR, 15.9; 95% CI, 2.76-91.9). No statistically significant difference was observed between the groups in terms of the rate of technical success, adverse events, or mortality. CONCLUSION: DPDS was associated with higher rate of PFC recurrence after successful endoscopic treatment of PFCs. Future studies should evaluate effectiveness and optimal duration of long-term placement of transmural plastic stents for PFCs with DPDS.

BACKGROUND: The value of contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) for T-staging in patients with extrahepatic bile duct cancer was evaluated. METHODS: This single-center, retrospective study included consecutive patients with extrahepatic bile duct cancer who underwent surgical resection after preoperative EUS, CH-EUS, and contrast-enhanced CT (CE-CT) examinations between June 2014 and August 2017. The capacity of these modalities for T-staging of extrahepatic bile duct cancer was evaluated by assessing invasion beyond the biliary wall into the surrounding tissue, gallbladder, liver, pancreas, duodenum, portal vein system (portal vein and/or superior mesenteric vein), inferior vena cava, and hepatic arteries (proper hepatic artery, right. and/or left. hepatic artery). Blind reading of EUS, CH-EUS, and CE-CT images was performed by two expert reviewers each. RESULTS: 38 patients were eligible for analysis, of which eight had perihilar bile duct cancer and 30 had distal bile duct cancer. Postoperative T-staging was T1 in 6, T2 in 16, and T3 in 16 cases. CH-EUS was superior to CE-CT for diagnosing invasion beyond the biliary wall into surrounding tissue (92.1% vs. 45.9%, P = 0.0002); the ability to detect invasion to other organs did not differ significantly between the two modalities. The accuracy of CH-EUS for T-staging of tumors was better than that of CE-CT (73.7% vs. 39.5%, P = 0.0059). CH-EUS tended to have a better accuracy than EUS for the diagnosis of invasion beyond the biliary wall into the surrounding tissue (92.1% vs. 78.9%, P = 0.074) and T-staging (73.7% vs. 60.5%, P = 0.074). CONCLUSION: CH-EUS is useful for T-staging of extra hepatic bile duct cancer, especially in terms of invasion beyond the biliary wall into the surrounding tissue.

Due to the tendency of gastric linitis plastica (GLP) to cause extensive submucosal infiltration, a superficial endoscopic biopsy sometimes yields no evidence of malignancy, hindering definite diagnosis. The present study was a single-center retrospective analysis of 54 consecutive patients diagnosed with GLP between 2016 and 2020 to evaluate EUS-guided fine-needle aspiration (EUS-FNA) biopsy outcomes in patients with negative endoscopic biopsy findings. A pathological GLP diagnosis was achieved by endoscopic biopsy in 40 patients (74.1%). EUS-FNA biopsy with a 22-gauge needle was performed in 13 of the remaining 14 patients, and GLP diagnosis was confirmed in 10 patients, with a median of three needle passes. The remaining four patients were laparoscopically diagnosed with GLP. The diagnostic ability of EUS-FNA biopsy for GLP was 76.9%, and EUS-FNA biopsy contributed to GLP diagnosis in 18.5% (10/54) of all cases. None of the 13 patients exhibited EUS-FNA biopsy-related adverse events. Univariable and multivariable analyses revealed an absence of superficial ulcerations as a predictor of false-negative endoscopic biopsy findings in patients with GLP. These results suggest EUS-FNA biopsy as a minimally invasive and safe alternative diagnostic modality for GLP in cases where conventional endoscopic biopsy fails to verify malignancy, although prospective studies with larger cohorts are warranted to confirm these findings.

INTRODUCTION: The management of small pancreatic neuroendocrine neoplasms (PNENs) remains controversial. The standard treatment for PNENs is surgical resection; however, invasiveness of surgical procedure remains higher and the incidence of postoperative adverse events is still high. Recently, the efficacy and safety of endoscopic ultrasonography (EUS)-guided ethanol injection for small PNENs has been preliminarily demonstrated. Thus, a multicentre prospective study is being conducted to evaluate the efficacy and safety of EUS-guided ethanol injection therapy for small PNENs. METHODS AND ANALYSIS: The major eligibility criteria are the presence of pathologically diagnosed grade (G) 1 tumour, a tumour size of ≤15 mm and non-functional PNEN or insulinoma. For treatment, we will use a 25-gauge needle and pure ethanol. Contrast-enhanced CT (CE-CT) will be performed on postoperative day 3-5, and if enhanced areas of the tumour are still apparent, an additional session is scheduled during the same hospitalisation period. We set the total amount of ethanol per session to 2 mL. To evaluate the efficacy and safety, CE-CT will be performed at 1 and 6 months after treatment. The primary endpoint is the percentage of subjects who achieved all of the following evaluated points. Efficacy will be evaluated based on the achievement of complete ablation (defined as no enhanced area within the tumour on CE-CT) at 1 and 6 months. Safety will be evaluated based on the avoidance of severe adverse events within 1 month after treatment, continuing severe pancreatic fistula at 1 month after treatment and the incidence and/or exacerbation of diabetes mellitus at 6 months after treatment. ETHICS AND DISSEMINATION: This protocol has been approved by Okayama University Certified Review Board (approval number. CRB19-007). The results will be submitted to peer-reviewed journals and will be presented at international conferences. TRIAL REGISTRATION NUMBER: jRCTs061200016.

BACKGROUND: Preparation for colon capsule endoscopy (CCE) requires a large liquid laxative volume for capsule excretion, which compromises the procedure's tolerability. AIM: To assess the safety and utility of castor oil-boosted bowel preparation. METHODS: This prospective cohort study including 20 patients (age range, 16-80 years; six men and 14 women) suspected of having colorectal disease was conducted at Kindai University Hospital from September 2017 to August 2019. All patients underwent CCE because of the following inclusion criteria: previous incomplete colonoscopy in other facility (n = 20), history of abdominal surgery (n = 7), or organ abnormalities such as multiple diverticulum (n = 4) and adhesion after surgery (n = 6). The exclusion criteria were as follows: Dysphagia, history of allergic reactions to the drugs used in this study (magnesium citrate, polyethylene glycol, metoclopramide, and castor oil), possibility of pregnancy, possibility of bowel obstruction or stenosis based on symptoms, or scheduled magnetic resonance imaging within 2 wk after CCE. The primary outcome was the capsule excretion rate within the battery life, as evaluated by the total large bowel observation rate, large bowel transit time, and bowel creasing level using a five-grade scale in different colorectal segments. The secondary outcomes were complications, colorectal lesion detection rates, and patients' tolerability. RESULTS: The castor oil-based regimen was implemented in 17 patients. Three patients cancelled CCE because they could tolerate castor oil, but not liquid laxatives. The capsule excretion rate within the battery life was 88% (15/17). The mean large bowel transit time was 236 min. Approximately 70% of patients had satisfactory colon cleansing levels. CCE detected colon polyps (14/17, 82%) and colonic diverticulum (4/12, 33%). The sensitivity, specificity, and diagnostic accuracy rates for detecting colorectal polyps (size ≥ 6 mm) were 76.9%, 75.0%, and 76.4%, respectively. The sensitivity, specificity, and diagnostic accuracy rates for detection of diverticulum were 100% each. Twelve patients (71%) rated CCE as more than "good", confirming the new regimen's tolerability. No serious adverse events occurred during this study. CONCLUSION: The castor oil-based regimen could reduce bowel preparation dose and improve CCE tolerability.

BACKGROUND AND AIMS: Pancreatic neuroendocrine neoplasms (PanNENs), including Grade 1 (G1) or G2 tumors, can have a poor prognosis. This study investigated the value of contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) for predicting the prognosis of PanNENs. METHODS: This single-center, retrospective study included 47 consecutive patients who underwent CH-EUS and were diagnosed with PanNEN by surgical resection or EUS-guided fine needle aspiration between December 2011 and February 2016. Patients were divided into aggressive and non-aggressive groups according to the degree of clinical malignancy. CH-EUS was assessed regarding its capacity for diagnosing aggressive PanNEN, the correspondence between contrast patterns and pathological features, and its ability to predict the prognosis of PanNEN. RESULTS: There were 19 cases of aggressive PanNEN and 28 cases of non-aggressive PanNEN. The aggressive group included three G1, four G2, three G3 tumors, three mixed neuroendocrine non-neuroendocrine neoplasms, and six neuroendocrine carcinomas. CH-EUS was superior to contrast-enhanced computed tomography for the diagnosis of aggressive PanNEN (P < 0.001): hypo-enhancement on CH-EUS was an indicator of aggressive PanNEN, with sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 94.7%, 100%, 100%, 96.6%, and 97.9%, respectively. Among G1/G2 PanNENs, cases with hypo-enhancement on CH-EUS had a poorer prognosis than those with hyper/iso-enhancement (P = 0.0009). Assessment of 36 resected specimens showed that hypo-enhancement on CH-EUS was associated with smaller and fewer vessels and greater degree of fibrosis. CONCLUSION: Contrast-enhanced harmonic endoscopic ultrasonography may be useful for predicting the prognosis of PanNENs.

Colonic diverticular could bleed recurrently, and, sometimes, fatal massive bleeding could occur. However, the choice of endoscopic hemostasis remains controversial. Although the over-the-scope clip (OTSC) method has been reported to be effective, it has not been fully evaluated due to the small number of cases. This study aimed to evaluate the efficacy of the OTSC method for colonic diverticular bleeding. Between August 2017 and December 2020, 36 consecutive patients, including those who could not be treated using endoscopic band ligation (EBL) and those in whom re-bleeding had occurred after EBL, underwent the OTSC method for hemostasis of colonic diverticular bleeding at Hyogo Prefectural Awaji Medical Center. The procedure success rate, adverse events rate, early phase re-bleeding rate (within 30 days following primary hemostasis), and the requirement rate for additional transcatheter arterial embolization (TAE) or surgery were the outcomes assessed. The outcomes were procedure success rate 100%, adverse events rate 0%, early phase re-bleeding rate 8.3%, and additional TAE or surgery rate 0%. These results suggest that the OTSC method is a safe and effective treatment for managing colonic diverticular bleeding.

Unsuccessful stent replacement in transpapillary biliary drainage with plastic stents (PSs) has a significant impact on patient prognosis; thus, a safe and reliable replacement method is required. We aimed to compare the snare-over-the-guidewire (SOG) method, wherein the PS lumen is used as an access route to the biliary tract and the PS is removed with a snare inserted via the inserted guidewire, with the conventional side-of-stent (SOS) method, wherein the biliary approach is performed from the side of the PS. This retrospective single-center study included 244 consecutive patients who underwent biliary PS replacement between January 2018 and July 2020. The procedural success rates were compared between the two methods. A predictive analysis of unsuccessful PS replacement was also performed. The procedural success rate in the SOG group was significantly higher than that in the SOS group (p = 0.026). In the proximal biliary stenosis lesion, the same trend was observed (p = 0.025). Multivariate analysis also showed that the SOS method (p = 0.0038), the presence of proximal biliary stenosis (p < 0.0001), and parapapillary diverticulum (p = 0.0007) were predictors of unsuccessful PS replacement. The SOG method may be useful for biliary PS replacement, especially in cases of proximal hilar bile duct stenosis.

BACKGROUND AND AIMS: EUS-guided hepaticogastrostomy (EUS-HGS) is associated with high rates of adverse events. The present study evaluated the feasibility of a newly designed stent equipped with a dilatation and antimigration system for EUS-HGS in phantom and animal models. METHODS: The newly designed stent was a partially covered laser-cut stent with antimigration anchoring hooks and a thin tapered tip (7.2F). The feasibility of these stents for biliary obstruction was compared with that of conventional stents. Evaluated outcomes were resistance force to migration in phantom and ex vivo models, rates of technical success and adverse events, and histology in an in vivo model. RESULTS: The resistance forces on the distal (3.59 vs 1.73 N and 6.21 vs 1.74 N) and proximal (3.58 vs 1.5 N and 5.97 vs 1.67 N) sides in phantom and ex vivo models were significantly higher for hook stents than for conventional stents. Although EUS-HGS was successfully performed in all cases with both stents (100% [10/10] vs 100% [8/8]), the success rate of EUS-HGS without using a fistulous tract dilation device was significantly higher with hook stents (100% [10/10]) than with conventional stents (13% [1/8]). No adverse events occurred with either stent. Pathologic examination showed adhesion between the stomach and liver. CONCLUSIONS: The strong resistance to migration and the absence of the dilation step are important advantages of newly designed hook stents. These stents may therefore be feasible and safe for EUS-HGS.

BACKGROUND/PURPOSE: This study aimed to evaluate the feasibility of endoscopic ultrasound (EUS)-guided antegrade covered stent placement with long duodenal extension (EASL) for malignant distal biliary obstruction (MDBO) with duodenal obstruction (DO) or surgically altered anatomy (SAA) after failed endoscopic retrograde cholangiopancreatography (ERCP). METHODS: Outcomes were technical and clinical success, reintervention rate, adverse events, stent patency, and overall survival. Inverse probability of treatment weighting (IPTW) and competing-risk analysis were performed to compare with conventional EUS-BD. RESULTS: Twenty-five patients (DO, n = 18; SAA, n = 7) were included. The technical and clinical success rates were 96% and 84%, respectively. Reintervention occurred in two patients (8.3%). Adverse events occurred in six patients (24%; two cholangitis, 16%; four mild postprocedural pancreatitis [24% (n = 4/17) in patients with non-pancreatic cancers]). The median patency was 9.4 months, and the overall survival was 2.73 months. After IPTW adjustment, the median patency in the EASL (n = 25) and conventional EUS-BD (n = 29) were 10.1 and 6.5 months, respectively (P = .018). CONCLUSIONS: EASL has acceptable clinical outcomes with a low reintervention rate but higher rate of postprocedural pancreatitis in patients with non-pancreatic cancers. Randomized trials comparing EASL and conventional EUS-BD for MDBO with pancreatic cancers and DO/SAA after failed ERCP are needed to validate our findings.

BACKGROUND AND AIM: Bilateral stent deployment for malignant biliary obstruction (MHBO) can be achieved using side-by-side (SBS) or stent-in-stent (SIS) procedures. Compared with SBS techniques, the procedural steps of SIS are technically complex due to the necessity of introducing the delivery system into a contralateral biliary tract through the mesh of the SEMS. To overcome this issue, a novel uncovered SEMS, the HILZO Moving Cell Stent (MCS) has been released. The present study examined the technical feasibility of treating MHBO using bilateral deployment of this novel stent without dilating the mesh of the first stent to achieve insertion of the second stent within a single session, using a prospective, multicenter setting. METHOD: The primary outcome in the present study was the technical success rate. Technical success was defined as deployment of bilateral MCSs into two or more biliary tracts using SIS without a dilation device in a single-session. RESULTS: A total of 27 patients with complications of MHBO were enrolled in this study. Bilateral SIS using two MCS was successfully performed in 23 patients without using dilation devices among 27 patients (initial technical success rate; 85.2%). Median time to recurrent biliary obstruction (TRBO) was 271 days. Stent dysfunction was observed in 12 patients (44.4%), and re-intervention was successfully performed in all patients without one patient who instead received best supportive care. CONCLUSIONS: The SIS technique using MCS without dilation of the mesh may be technically feasible and safe. In addition, this may be useful for re-intervention. Further comparative randomized trials are needed.

OBJECTIVES: The transpapillary drainage by endoscopic retrograde cholangiopancreatography (ERCP-D) cannot be performed without fluoroscopy, and there are many situations in which fluoroscopy is required even in endoscopic ultrasound-guided drainage (EUS-D). Previous studies have compared the efficacy, but not the radiation exposure of EUS-D and ERCP-D. While radiation exposure in ERCP-D has been previously evaluated, there is a paucity of information regarding radiation doses in EUS-D. This study aimed to assess radiation exposure in EUS-D compared with that in ERCP-D. METHODS: This retrospective single-center cohort study included consecutive patients who underwent EUS-D and ERCP-D between October 2017 and March 2019. The air kerma (AK, mGy), kerma-area product (KAP, Gycm2 ), fluoroscopy time (FT, min), and procedure time (PT, min) were assessed. The invasive probability weighting method was used to qualify the comparisons. RESULTS: We enrolled 372 and 105 patients who underwent ERCP-D and EUS-D, respectively. The mean AK, KAP, and FT in the EUS-D group were higher by 53%, 28%, and 27%, respectively, than those in the ERCP-D group, whereas PT was shorter by approximately 11% (AK, 135.0 vs. 88.4; KAP, 28.1 vs. 21.9; FT, 20.4 vs. 16.0; PT, 38.7 vs. 43.5). The sub-analysis limited to biliary drainage cases showed the same trend (AK, 128.3 vs. 90.9; KAP, 27.0 vs. 22.2; FT, 16.4 vs. 16.1; PT, 32.5 vs. 44.4). CONCLUSIONS: This is the first study to assess radiation exposure in EUS-D compared with that in ERCP-D. Radiation exposure was significantly higher in EUS-D than in ERCP-D, despite the shorter procedure time.

BACKGROUND AND AIM: Recombinant thrombomodulin (rhTM) is potentially effective in the treatment of disseminated intravascular coagulation (DIC). Several studies related to drugs for the treatment of acute cholangitis have shown negative results in improvement of overall survival (OS) with rhTM. The aim of this multicenter study was to evaluate the clinical effectiveness of rhTM in patients with acute cholangitis and sepsis-induced DIC who underwent biliary drainage. METHODS: A total of 284 consecutive patients, who were complicated with sepsis-induced DIC due to severe acute cholangitis, were included (rhTM group, n = 173; non-rhTM, n = 111) in this study. The primary outcome was the DIC resolution rate at 7 days after starting treatment. The 28-day survival rate was secondarily evaluated. RESULTS: DIC scores in the rhTM group improved significantly compared with the non-rhTM group on day 7 (P = .020). According to multivariate analysis, etiology of cholangitis (malignant, HR 2.28), rhTM (non-administration, HR 4.13), and DIC score (≥5, HR 2.46) were significant factors associated with failed DIC resolution on day 7. Propensity score matching created 103 matched pairs. Survival rate at day 28 was significantly higher in rhTM group (94.3%) compared with non-rhTM group (82.6%; P = .048) after propensity score matching. rhTM (non-administration, HR 2.870), DIC score (≥5, HR 2.751), and APACHE II score (≥20, HR 9.310) were significant factors associated with decreasing survival rate at day 28. CONCLUSION: In conclusion, rhTM seemed to improve patient survival, but future studies should only include patients with benign or malignant disease and should be performed according to APACHE II scores.

This study aimed to investigate whether the incorporation of contrast-enhanced harmonic endoscopic ultrasound (CH-EUS) into the international consensus guidelines (ICG) for the management of intraductal papillary mucinous neoplasm (IPMN) could improve its malignancy diagnostic value. In this single-center retrospective study, 109 patients diagnosed with IPMN who underwent preoperative CH-EUS between March 2010 and December 2018 were enrolled. We analyzed each malignancy diagnostic value (sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV)) by replacing fundamental B-mode EUS with CH-EUS as the recommended test for patients with worrisome features (WF) (the CH-EUS incorporation ICG) and comparing the results to those obtained using the 2017 ICG. The malignancy diagnostic values as per the 2017 ICG were 78.9%, 42.3%, 60.0%, and 64.7% for Se, Sp, PPV, and NPV, respectively. The CH-EUS incorporation ICG plan improved the malignancy diagnostic values (Se 78.9%/Sp, 53.8%/PPV, 65.2%/NPV 70.0%). CH-EUS may be useful in determining the appropriate treatment strategies for IPMN.

Background and aims: It is essential for endoscopists, technologists, and nurses to understand radiation protection. However, protective equipment usage is still low, and there is little awareness of radiation protection in practice. Methods: We conducted a questionnaire survey on radiation protection from January to February 2020. The participants were medical staff, including medical doctors, nurses, and radiological and endoscopy technician in endoscopy-fluoroscopy departments. The questionnaire included 14 multiple-choice questions divided among three parts: background, equipment, and knowledge. Results: We surveyed a total of 282 subjects from 26 institutions. There were 168 medical doctors (60%), 90 nurses (32%), and 24 technologists (9%). Although almost all staff members (99%) always wore a lead apron, only a few wore a thyroid collar (32%) and lead glasses (21%). The rate of wearing a radiation dosimeter was insufficient (69%), especially among doctors (52%). A few subjects knew the radiation exposure dose of each procedure (15%), and slightly over half had attended lectures on radiation protection (64%) and knew about the three principles of radiation protection (59%). Protection adherence did not differ by years of experience, knowledge of fluoroscopy, awareness of radiation exposure doses, or attendance at basic lectures on radiation protection. However, medical doctors who were aware of the radiation exposure dose of each procedure were significantly more likely to wear dosimeters than those who were not (p = 0.0008). Conclusion: Medical staff in endoscopy departments in Japan do not have enough radiation protection equipment or education.

INTRODUCTION: In patients with malignant distal bile duct obstruction and normal gastrointestinal anatomy, endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) is indicated when endoscopic retrograde cholangiopancreatography (ERCP) fails. The ERCP drainage route passes through the tumor, whereas the EUS-CDS route does not. Therefore, EUS-CDS is expected to have a longer stent patency than ERCP. However, for first-line biliary drainage, it remains unclear whether EUS-CDS or ERCP is superior in terms of stent patency. To reduce the frequency of highly adverse events (AEs) such as bile peritonitis or stent migration following EUS-CDS, we developed an antimigration metal stent with a thin delivery system for tract dilatation. This study is designed to assess whether EUS-CDS with this novel stent is superior to ERCP with a traditional metal stent in terms of stent patency when the two techniques are used for first-line drainage of malignant distal biliary obstruction. METHODS/DESIGN: This study is a multicenter single-blinded randomized controlled trial (RCT) involving 95 patients in four tertiary centers. Patients with malignant distal biliary obstruction that is unresectable or presents a very high surgical risk and who pass the inclusion and exclusion criteria will be randomized to EUS-CDS or ERCP in a 1:1 proportion. The primary endpoint is the stent patency rate 180 days after stent insertion. Secondary outcomes include the rates of technical success, clinical success, technical success in cases not requiring fistulous-tract dilation (only EUS-CDS group), procedure-related AEs, re-intervention success, patients receiving post-drainage chemotherapy, procedure time, and overall survival time. DISCUSSION: If EUS-CDS is superior to ERCP in terms of stent patency and safety for the first-line drainage of malignant distal biliary obstruction, it is expected that the first-line drainage method will be changed from ERCP to EUS-CDS, and that interruption of chemotherapy due to stent dysfunction can be avoided. TRIAL REGISTRATION: University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR), ID: UMIN000041343. Registered on August 6, 2020. https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000047201Version number: 1.2, December 7, 2020.

INTRODUCTION: The global needs for a reduction in radiation exposure (RE) are increasing. Endoscopic retrograde cholangiopancreatography (ERCP) is a significant fluoroscopic procedure in the gastrointestinal field. However, the actual RE in ERCP and its annual trend are still unclear. Therefore, we examined the yearly trend of RE in ERCP. METHODS: This retrospective, single-center cohort study included consecutive cases of ERCP from September 2012 to June 2019. We measured the air kerma (AK, mGy), dose area product (DAP, Gycm2), and fluoroscopy time (FT, min). We also evaluated the annual trend of the RE before and after the fluoroscopy device update. RESULTS: In total, 2,174 patients receiving ERCP were enrolled. Among these, the mean age was 74.3 years, and 913 patients were women (42.0%). The median/third quartile values of AK (mGy), DAP (Gycm2), and FT (min) were 109/234 mGy, 13.3/25.8 Gycm2, and 18.2/27.7 minutes. The annual AK, DAP, and FT from 2012 to 2019 were 138, 207, 173, 177, 106, 71.0, 45.0, and 33.3 mGy; 23, 21.4, 19, 18.3, 11.9, 9.0, 6.8, and 6.4 Gycm2; and 12.5, 12.1, 9.7, 9.8, 8.2, 10.8, 9.4, and 10.3 minutes, respectively. The corresponding values before and after the update in July 2016 were 177 and 52 mGy (P < 0.0001), 19.2 and 7.6 Gycm2 (P < 0.0001), and 10.2, and 9.9 minutes (P = 0.05), respectively. DISCUSSION: The RE from ERCP tended to decrease every year, especially after fluoroscopy device updates.

Convolutional neural networks (CNNs) are widely used for artificial intelligence (AI)-based image classification. Residual network (ResNet) is a new technology that facilitates the accuracy of image classification by CNN-based AI. In this study, we developed a novel AI model combined with ResNet to diagnose colorectal polyps. In total, 127,610 images consisting of 62,510 images with adenomatous polyps, 30,443 with non-adenomatous hyperplastic polyps, and 34,657 with healthy colorectal normal mucosa were subjected to deep learning after annotation. Each validation process was performed using 12,761 stored images of colorectal polyps by a 10-fold cross validation. The efficacy of the ResNet system was evaluated by sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy. The sensitivity, specificity, PPV, NPV, and diagnostic accuracy for adenomatous polyps at WLIs were 98.8%, 94.3%, 90.5%, 87.4%, and 92.8%, respectively. Similar results were obtained for adenomatous polyps at narrow-band imagings (NBIs) and chromoendoscopy images (CEIs) (NBIs vs. CEIs: sensitivity, 94.9% vs. 98.2%; specificity, 93.9% vs. 85.8%; PPV, 92.5% vs. 81.7%; NPV, 93.5% vs. 99.9%; and overall accuracy, 91.5% vs. 90.1%). The ResNet model is a powerful tool that can be used for AI-based accurate diagnosis of colorectal polyps.

BACKGROUND AND AIMS: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is used for the histopathological diagnosis of any type of gastrointestinal disease. Few adverse events are experienced with this procedure; however, the actual rate of adverse events remains unclear. This study aimed to clarify the current status of cases that experienced adverse events related to the EUS-FNA procedure used for histopathologic diagnoses. METHODS: A retrospective analysis of cases with EUS-FNA-related adverse events in Japanese tertiary centers was conducted by assessing the following clinical data: basic case information, FNA technique, type of procedural adverse events, and prognosis. RESULTS: Of the 13,566 EUS-FNA cases overall, the total number of cases in which adverse events related to EUS-FNA occurred was 234. The incidence of EUS-FNA-related adverse events was ~1.7%. Bleeding and pancreatitis cases accounted for ~49.1% and 26.5% of all adverse events, respectively. Bleeding was the most common adverse event with only seven cases requiring blood transfusion. In cases with neuroendocrine tumors, pancreatitis was the most frequent adverse event. Needle tract seeding because of EUS-FNA was observed during the follow-up period in only ~0.1% of cases with pancreatic cancer. There was no mortality because of adverse events caused by EUS-FNA. CONCLUSIONS: This study revealed that the adverse events-related EUS-FNA for histopathologic diagnoses were not severe conditions, and had low incidence.

Background and study aims  Fluoroscopy-guided gastrointestinal procedures (FGPs) are increasingly common. However, the radiation exposure (RE) to patients undergoing FGPs is still unclear. We examined the actual RE of FGPs. Patients and methods  This retrospective, single-center cohort study included consecutive FGPs, including endoscopic retrograde cholangiopancreatography (ERCP), interventional endoscopic ultrasound (EUS), enteral stenting, balloon-assisted enteroscopy, tube placement, endoscopic injection sclerotherapy (EIS), esophageal balloon dilatation and repositioning for sigmoid volvulus, from September 2012 to June 2019. We measured the air kerma (AK, mGy), dose area product (DAP, Gycm 2 ), and fluoroscopy time (FT, min) for each procedure. Results  In total, 3831 patients were enrolled. Overall, 2778 ERCPs were performed. The median AK, DAP, and FT were as follows: ERCP: 109 mGy, 13.3 Gycm 2 and 10.0 min; self-expandable enteral stenting (SEMS): 62 mGy, 12.4 Gycm 2 and 10.4 min; tube placement: 40 mGy, 13.8 Gycm 2 and 11.1 min; balloon-assisted enteroscopy: 43 mGy, 22.4 Gycm 2 and 18.2 min; EUS cyst drainage (EUS-CD): 96 mGy, 18.3 Gycm 2 and 10.4 min; EIS: 36 mGy, 8.1 Gycm 2 and 4.4 min; esophageal balloon dilatation: 9 mGy, 2.2 Gycm 2 and 1.8 min; and repositioning for sigmoid volvulus: 7 mGy, 4.7 Gycm 2 and 1.6 min. Conclusion  This large series reporting actual RE doses of various FGPs could serve as a reference for future prospective studies.

BACKGROUND: Pancreatic pleural effusion and ascites are defined as fluid accumulation in the thoracic and abdominal cavity, respectively, due to direct leakage of the pancreatic juice. They usually occur in patients with acute or chronic pancreatitis but are rarely associated with pancreatic neoplasm. We present here an extremely rare case of pancreatic neuroendocrine tumor with stenosis of the main pancreatic duct, leading to pancreatic pleural effusion. CASE PRESENTATION: A 51-year-old man complained of dyspnea. Left-sided pleural effusion was detected on the chest X-ray. Pleural puncture was performed, and the pleural fluid indicated a high amylase content (36,854 IU/L). Hence, the patient was diagnosed with pancreatic pleural effusion. Although no tumor was detected, the computed tomography (CT) scan showed a pseudocyst and dilation of the main pancreatic duct in the pancreatic tail. Magnetic resonance cholangiopancreatography showed a fistula from the pseudocyst into the left thoracic cavity. Endoscopic retrograde pancreatic drainage was attempted; however, it failed due to stenosis in the main pancreatic duct in the pancreatic body. Endoscopic ultrasound revealed a hypoechoic mass measuring 15 × 15 mm in the pancreatic body that was not enhanced in the late phase of contrast perfusion and was thus suspected to be an invasive ductal carcinoma. The patient underwent distal pancreatectomy with splenectomy and the postoperative course was uneventful. Histopathological examination confirmed a neuroendocrine tumor of the pancreas (NET G2). The main pancreatic duct was compressed by the tumor. Increased pressure on the distal pancreatic duct by the tumor might have caused formation of the pseudocyst and pleural effusion. To the best of our knowledge, this is the first case report of pancreatic pleural effusion associated with a neuroendocrine tumor. CONCLUSIONS: Differential diagnosis of a pancreatic neoplasm should be considered, especially when a patient without a history of pancreatitis presents with pleural effusion.

IgG4-related disease (IgG4-RD) is a multi-organ autoimmune disease characterized by elevated serum IgG4 concentration. Although serum IgG4 concentration is widely used as a biomarker for IgG4-RD and type 1 autoimmune pancreatitis (AIP), a pancreatic manifestation of IgG4-RD, a significant number of patients have normal serum IgG4 levels, even in the active phase of the disease. Recently, we reported that the development of experimental AIP and human type 1 AIP is associated with increased expression of IFN-α and IL-33 in the pancreas. In this study, we assessed the utility of serum IFN-α and IL-33 levels as biomarkers for type 1 AIP and IgG4-RD. Serum IFN-α and IL-33 concentrations in patients who met the diagnostic criteria for definite type 1 AIP and/or IgG4-RD were significantly higher than in those with chronic pancreatitis or in healthy controls. Strong correlations between serum IFN-α, IL-33, and IgG4 concentrations were observed. Diagnostic performance of serum IFN-α and IL-33 concentrations as markers of type 1 AIP and/or IgG4-RD was comparable to that of serum IgG4 concentration, as calculated by the receiver operating characteristic curve analysis. Induction of remission by prednisolone treatment markedly decreased the serum concentration of these cytokines. We conclude that serum IFN-α and IL-33 concentrations can be useful as biomarkers for type 1 AIP and IgG4-RD.

Background: This study aimed to evaluate and identify the specific CT findings by focusing on abnormalities in the main pancreatic duct (MPD) and pancreatic parenchyma in patients with small pancreatic cancer (PC) including carcinoma in situ (CIS). Methods: Nine CT findings indicating abnormalities of MPD and pancreatic parenchyma were selected as candidate findings for the presence of small PC ≤ 10 mm. The proportions of patients positive for each finding were compared between small PC and benign MPD stenosis groups. Interobserver agreement between two independent image reviewers was evaluated using kappa statistics. Results: The final analysis included 24 patients with small PC (including 11 CIS patients) and 28 patients with benign MPD stenosis. The proportion of patients exhibiting partial pancreatic parenchymal atrophy (PPA) corresponding to the distribution of MPD stenosis (45.8% vs. 7.1%, p < 0.01), upstream PPA arising from the site of MPD stenosis (33.3% vs. 3.6%, p = 0.01), and MPD abrupt stenosis (45.8% vs. 14.3%, p = 0.03) was significantly higher in the small PC group than in the benign MPD stenosis group. Conclusions: The presence of partial PPA, upstream PPA, and MPD abrupt stenosis on a CT image was highly suggestive of the presence of small PCs including CIS.

BACKGROUND: Although several techniques for endoscopic ultrasound-guided biliary drainage (EUS-BD) are available at present, an optimal treatment algorithm of EUS-BD has not yet been established. AIM: To evaluate the clinical utility of treatment method conversion during single endoscopic sessions for difficult cases in initially planned EUS-BD. METHODS: This was a single-center retrospective analysis using a prospectively accumulated database. Patients with biliary obstruction undergoing EUS-BD between May 2008 and April 2016 were included. The primary outcome was to evaluate the improvement in EUS-BD success rates by converting the treatment methods during a single endoscopic session. Secondary outcomes were clarification of the factors leading to the conversion from the initial EUS-BD and the assessment of efficacy and safety of the conversion as judged by technical success, clinical success, and adverse events (AEs). RESULTS: A total of 208 patients underwent EUS-BD during the study period. For 18.8% (39/208) of the patients, the treatment methods were converted to another EUS-BD technique from the initial plan. Biliary obstruction was caused by pancreatobiliary malignancies, other malignant lesions, biliary stones, and other benign lesions in 22, 11, 4, and 2 patients, respectively. The reasons for the difficulty with the initial EUS-BD were classified into the following 3 procedures: Target puncture (n = 13), guidewire manipulation (n = 18), and puncture tract dilation (n = 8). Technical success was achieved in 97.4% (38/39) of the cases and clinical success was achieved in 89.5% of patients (34/38). AEs occurred in 10.3% of patients, including bile leakage (n = 2), bleeding (n = 1), and cholecystitis (n = 1). The puncture target and drainage technique were altered in subsequent EUS-BD procedures in 25 and 14 patients, respectively. The final technical success rate with 95%CI for all 208 cases was 97.1% (95%CI: 93.8%-98.9%), while that of the initially planned EUS-BD was 78.8% (95%CI: 72.6%-84.2%). CONCLUSION: Among multi-step procedures in EUS-BD, guidewire manipulation appeared to be the most technically challenging. When initially planned EUS-BD is technically difficult, treatment method conversion in a single endoscopic session may result in successful EUS-BD without leading to severe AEs.

INTRODUCTION: Recently, the use of various endoscopic procedures under X-ray fluoroscopic guidance, such as endoscopic retrograde cholangiopancreatography (ERCP), interventional endoscopic ultrasonography (EUS), enteral endoscopy and stenting, has been rapidly increasing because of the minimally invasive nature of these procedures compared with that of surgical intervention. With the spread of CT and fluoroscopic interventions, including endoscopic procedures under X-ray guidance, high levels of radiation exposure (RE) from medical imaging have led to major concerns throughout society. However, information about RE related to these image-guided procedures in gastrointestinal endoscopy is scarce, and the RE reference levels have not been established. The aim of this study is to prospectively collect the actual RE dose and to help establish diagnostic reference levels (DRLs) in the field of gastroenterology in Japan. METHODS AND ANALYSIS: This is a multicentre, prospective observational study that is being conducted to collect the actual RE from treatments and diagnostic procedures, including ERCP, interventional EUS, balloon-assisted enteroscopy, enteral metallic stent placement and enteral tube placement. We will measure the total fluoroscopy time (min), the total dose-area product (Gycm2) and air-kerma (mGy) of those procedures. Because we are collecting the actual RE data and identifying the influential factors through a prospective, nationwide design, this study will provide guidance regarding the DRLs of ERCP, interventional EUS, balloon-assisted enteroscopy, enteral metallic stent placement and enteral tube placement. ETHICS AND DISSEMINATION: Approval was obtained from the Institutional Review Board of Toyonaka Municipal Hospital (25 April 2019). The need for informed consent will be waived via the opt-out method of each hospital website. TRIAL REGISTRATION NUMBER: The UMIN Clinical Trials Registry, UMIN000036525.

BACKGROUND: Self-expandable metal stents (SEMSs) are widely used in patients with distal malignant biliary obstruction. A SEMS that can avoid occlusion as much as possible is desirable. AIMS: The aim of this multicenter single-arm prospective study was to assess the clinical effectiveness and safety of a novel fully covered braided SEMS. METHODS: We enrolled consecutive patients with distal malignant biliary obstruction between February 2016 and November 2017 at ten tertiary-care medical centers. RESULTS: We included 79 patients with a median age of 76 years; 47 (59.5%) patients were men. The technical and clinical success rate was 98.7% and 93.6%, respectively. Recurrent biliary obstruction occurred in 14 patients (17.9%); stent ingrowth, overgrowth, migration, and other occurred in five (6.4%), four (5.1%), four (5.1%), and one (1.3%) patients, respectively. All reinterventions in patients with recurrent biliary obstruction were successful via the transpapillary approach. Adverse events occurred in 15 patients (19.2%); cholangitis, pancreatitis, and others occurred in ten (12.8%), three (3.8%), and two (2.6%) patients, respectively. The stent patency probability at 6 months was 48.5%. Median time to stent patency was 171 days, median time to recurrent biliary obstruction was 536 days, and median survival time was 195 days. CONCLUSIONS: We confirmed the utility and safety of a novel fully covered braided SEMS with low axial force and high radial force in patients with malignance biliary obstruction. This novel SEMS is recommended in patients with distal malignant biliary obstruction.

BACKGROUND AND AIMS: Histologic diagnosis of autoimmune pancreatitis (AIP) using EUS-guided FNA (EUS-FNA) is difficult. To address this issue, new fine-needle biopsy (FNB) needles were recently developed. Here, we prospectively evaluated 2 newly designed EUS-FNB needles for histologic evaluation in patients with type 1 AIP. METHODS: This was a prospective, randomized, multicenter trial comparing biopsy specimens obtained with a 22-gauge Franseen needle or a 20-gauge forward-bevel needle in patients with suspected type 1 AIP. AIP was diagnosed according to international consensus diagnostic criteria. The primary endpoint was the sensitivity of EUS-FNB needles, and secondary endpoints were the amount of specimen obtained, histology of the pancreas based on evaluation of lymphoplasmacytic sclerosing pancreatitis (LPSP), and contribution of histologic findings to the diagnosis of AIP. RESULTS: One hundred ten patients were randomly assigned to the Franseen group (22-gauge Franseen needle) or the forward-bevel group (20-gauge forward-bevel needle). EUS-FNB sampling was successful in all patients. Nine patients were excluded because of diagnoses other than AIP. Compared with the forward-bevel needle, the Franseen needle obtained a significantly greater number of high-power fields. Of 101 patients, 39 patients (78%) in the Franseen group and 23 patients (45%) in the Forward-bevel group were diagnosed with level 1 or 2 LPSP (P = .001). Thirty-six patients could not be diagnosed with type 1 AIP without EUS-FNB specimen results. CONCLUSIONS: The 22-gauge Franseen needle should be routinely used for histologic diagnosis of type 1 AIP. (Clinical trial registration number: UMIN 000027668.).

PURPOSE: To examine whether MRCP using a combination of compressed sensing and sensitivity encoding with navigator-triggered and breath-hold techniques (NT C-SENSE and BH C-SENSE, respectively) have comparable image quality to that of navigator-triggered MRCP using only sensitivity encoding (NT SENSE) at 1.5-T. METHODS: Fifty-one participants were enrolled in this prospective study between July and October 2018 and underwent the three 3D MRCP sequences each. The acquisition time and relative duct-to-periductal contrast ratios (RC values) of each bile duct segment were obtained. Visualization of the bile and main pancreatic ducts, background suppression, artifacts, and overall image quality were scored on 5-point scales. Mean and median differences in RC values and qualitative scores of NT C-SENSE and BH C-SENSE relative to NT SENSE were calculated with 95% confidence intervals (CIs). RESULTS: Acquisition time of NT SENSE, NT C-SENSE, and BH C-SENSE were 348, 143 (mean for both), and 18 s (for all participants), respectively. The RC value of each bile duct segment was inferior, but the lower limits of the 95% CIs of the mean differences were ≥ - 0.10, for both NT C-SENSE and BH C-SENSE. The visualization score of the intrahepatic duct in BH C-SENSE was inferior to that in NT SENSE (lower 95% CI limit, - 1.5). In both NT C-SENSE and BH C-SENSE, the 95% CIs of the median differences in the other qualitative scores were from - 1.0 to 0.0. CONCLUSION: NT C-SENSE and BH C-SENSE have comparable image quality to NT SENSE at 1.5-T.

PURPOSE: To examine whether MRCP using a combination of compressed sensing and sensitivity encoding with navigator-triggered and breath-hold techniques (NT C-SENSE and BH C-SENSE, respectively) have comparable image quality to that of navigator-triggered MRCP using only sensitivity encoding (NT SENSE) at 1.5-T. METHODS: Fifty-one participants were enrolled in this prospective study between July and October 2018 and underwent the three 3D MRCP sequences each. The acquisition time and relative duct-to-periductal contrast ratios (RC values) of each bile duct segment were obtained. Visualization of the bile and main pancreatic ducts, background suppression, artifacts, and overall image quality were scored on 5-point scales. Mean and median differences in RC values and qualitative scores of NT C-SENSE and BH C-SENSE relative to NT SENSE were calculated with 95% confidence intervals (CIs). RESULTS: Acquisition time of NT SENSE, NT C-SENSE, and BH C-SENSE were 348, 143 (mean for both), and 18 s (for all participants), respectively. The RC value of each bile duct segment was inferior, but the lower limits of the 95% CIs of the mean differences were ≥ - 0.10, for both NT C-SENSE and BH C-SENSE. The visualization score of the intrahepatic duct in BH C-SENSE was inferior to that in NT SENSE (lower 95% CI limit, - 1.5). In both NT C-SENSE and BH C-SENSE, the 95% CIs of the median differences in the other qualitative scores were from - 1.0 to 0.0. CONCLUSION: NT C-SENSE and BH C-SENSE have comparable image quality to NT SENSE at 1.5-T.

【背景と目的】超音波内視鏡下胆道ドレナージ術（Endoscopic ultrasound-guided biliary drainage；EUS-BD）には，endoscopic ultrasound-guided choledochoduodenostomy（EUS-CDS）およびendoscopic ultrasound-guided hepaticogastrostomy（EUS-HGS）の２つのアプローチ方法が存在する．本研究は，悪性胆道閉塞に対するこれらの２つの手技の有効性と安全性を比較検討した前向き無作為化試験である． 【方法】ERCPが不成功であった悪性遠位胆道閉塞を有する患者を対象とし，EUS-CDS群およびEUS-HGS群に無作為に割り付けた．本研究は，2013年９月から2016年３月の期間に国内の高次医療機関９施設で行われた．主要評価項目は手技成功率とし，片側有意水準５％，非劣性マージンを15％と設定し，EUS-HGSのEUS-CDSに対する非劣性を検討した．副次的評価項目は，臨床的成功率，偶発症発生率，ステント開存期間，生存時間，および初期治療，二次治療を含めたEUS-BDの手技成功率とした． 【結果】EUS-HGS群：24例，EUS-CDS群：23例の計47症例が登録された．手技成功率は，EUS-HGS群およびEUS-CDS群で，各々87.5％，82.6％であり，リスク差の90％信頼区間の下限は12.2％であった（P値＝0.0278）．臨床的成功率は，EUS-HGS群およびEUS-CDS群で，各々100％，94.7％であった（P値＝0.475）．偶発症発生率，ステント開存期間，生存期間には両群で差がなかった．EUS-BDの二次治療を含めた全体での手技成功率は，EUS-HGS群およびEUS-CDS群で各々100％，95.7％であった（P値＝0.983）． 【結語】本研究により手技成功に関してEUS-HGSのEUS-CDSに対する非劣性が示された．いずれかの手技が困難な場合，他のEUS-BD手技に切り替えることが手技成功を高めることにつながる可能性がある．

Background: Endoscopic treatment for malignant biliary obstruction (MBO) in patients bearing surgically altered anatomy (SAA) is not well-established. Although endoscopic ultrasound-guided biliary drainage (EUS-BD) has emerged as a new treatment option for MBO, limited data are available regarding the efficacy and safety of EUS-BD in patients with SAA. We conducted a multicenter prospective registration study to evaluate the efficacy and safety of EUS-BD in this population. Methods: This study involved 10 referral centers in Japan. Patients with SAA who were scheduled to receive EUS-BD for unresectable MBO between May 2016 and September 2018 were prospectively registered. The primary endpoint was technical success and the secondary outcomes were clinical success, procedure time, procedure-related adverse events (AEs), stent patency, and overall survival. Results: In total, 40 patients were prospectively enrolled. The surgical reconstruction methods were gastrectomy with Roux-en-Y reconstruction (47.5%), gastrectomy with Billroth-II reconstruction (15%), pancreaticoduodenectomy (27.5%), and hepaticojejunostomy with Roux-en-Y reconstruction (10%). EUS-BD was performed for primary biliary drainage in 31 patients and for rescue biliary drainage in nine patients. Transmural stenting alone (60%), antegrade stenting alone (5%), and a combination of the two techniques (35%) were selected for patients treated with EUS-BD. Technical and clinical success rates were 100% (95% confidence interval, 91.2-100.0%) and 95% (95% confidence interval, 83.1-99.4%), respectively. Mean procedure time was 36.5 min. Early AEs were noted in six patients (15%): three self-limited bile leak, one bile peritonitis, and two pneumoperitonea. Late AEs occurred in six patients (15%): one jejunal ulcer and five stent occlusions. Stent patency rate after 3 months of survival was 95.7% (22/23). Median overall survival was 96 days. Conclusion: EUS-BD for MBO in patients with SAA appears to be effective and safe not only as a rescue drainage technique after failed endoscopic retrograde cholangiography but also as a primary drainage technique. Clinical Trial Registration: UMIN000022101.

BACKGROUND: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) was developed with the aim of further improving the diagnostic performance of endoscopic ultrasound. Although novel puncture needles have been specifically designed for collecting sufficient tissue specimens, clinical studies have indicated no clear difference in diagnostic performance between these novel needles and conventional puncture needles. Recently, a needle with Franseen geometry was developed specifically for EUS-FNA biopsy. Due to the characteristic shape of its tip, the Franseen needle is expected to be effective for scraping tissues, thus potentially increasing the diagnostic accuracy of EUS-FNA biopsy. We plan to carry out a prospective, multicenter, open-labeled, controlled trial to compare conventional and Franseen needles in terms of the diagnostic accuracy of EUS-FNA for evaluating the malignancy of pancreatic mass lesions. METHODS/DESIGN: The study will enroll 520 patients with pancreatic mass managed at any of 21 participating endoscopic centers. Lesion samples obtained using 22G conventional and Franseen needles will be assessed to compare the efficacy and safety of these two types of needles in EUS-FNA for evaluating the malignancy of mass lesions in the pancreas. Tissue samples will be fixed in formalin and processed for histologic evaluation. For the purpose of this study, only samples obtained with the first needle pass will be used for comparing the: (i) accuracy of the malignancy diagnosis, (ii) sensitivity and specificity for the malignancy diagnosis, (iii) procedure completion rate, (iv) sample cellularity, and (v) incidence of complications. Patient enrollment begins on July 17, 2018. DISCUSSION: The outcomes of this study may provide insight into the optimal needle choice for evaluating the malignancy of pancreatic solid lesions, thus aiding in the development of practice guidelines for pancreatic diseases. TRIAL REGISTRATION: University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR), UMIN000030634. Registered on 29 December 2017. http://www.umin.ac.jp/ Version number: 01.2017.12.28.

現行の「慢性膵炎臨床診断基準2009」が提唱されてから10年間が経過した．世界ではじめて早期慢性膵炎の概念を取り入れた診断基準であるが，その後蓄積された知見や膵炎診療の変化をふまえて，その改訂が必要となっていた．今回，日本膵臓学会膵炎調査研究委員会慢性膵炎分科会が中心となり，診断基準の改訂を行った．新基準「慢性膵炎臨床診断基準2019」の最大の特徴は，mechanistic definitionを慢性膵炎の概念として取り入れ，早期慢性膵炎の診断項目を危険因子の観点から改訂したことである．新たに膵炎関連遺伝子異常と急性膵炎の既往を診断項目に組み入れ，診断特異度の向上を意図した．さらに，多量飲酒歴の基準を純エタノール換算80g/日から60g/日に変更するとともに，画像診断としてMRCP所見の格上げ，早期慢性膵炎の画像所見の整理を行った．新しい診断基準が慢性膵炎診療のさらなる質の向上や患者の予後改善に寄与することが期待される．

BACKGROUND AND AIM: The most common adverse event following an endoscopic retrograde cholangiopancreatography (ERCP) procedure is post-ERCP pancreatitis (PEP). Rectal nonsteroidal anti-inflammatory drug (NSAID) administration has shown promise to reduce the risk of PEP in high-risk patients. However, in contrast to high-risk patients, the role of NSAID administration in patients with low risk remains controversial. METHODS: We performed a prospective, single-center, single-blinded, two-arm parallel group, randomized controlled trial to clarify the efficacy of low dose (50 mg) rectal NSAID administration for preventing PEP in at-risk patients. Patients scheduled to undergo ERCP were randomized into two groups, those with and without rectal administration of diclofenac. Patients in the diclofenac group received 50 mg of rectal diclofenac 30 min before undergoing ERCP. The primary endpoint was rate of PEP. RESULTS: A total of 303 were randomized into the study groups. Four patients declined participation following randomization, and another two were withdrawn. As a result, a total of 147 patients were assigned to the diclofenac group and 150 to the control group. The baseline and procedural characteristics were similar in both groups. The primary endpoint of PEP occurrence was seen in 13 of 297 patients (4.4%), including eight (5.4%) in the diclofenac group and five (3.3%) in the control group (P = 0.286). Additionally, those results were not significantly different when patients were classified as low or high risk. CONCLUSIONS: Prophylactic low-dose rectal diclofenac did not reduce the incidence of PEP following ERCP in patients classified as low or high risk.

【背景と目的】本研究では，造影ハーモニック超音波内視鏡（contrast-enhanced harmonic EUS：CH-EUS）を併用した超音波内視鏡（endoscopic ultrasonography：EUS）による精査が膵管内乳頭粘液性腫瘍（intraductal papillary mucinous neoplasm：IPMN）に対する外科的切除後の残膵フォローアップに有用であるかを検討した． 【方法】本研究は，単一施設で行われたレトロスペクティブな研究である．2009年４月から2015年３月までにIPMNに対して外科的切除が施行された計134人の患者を対象とした．フォローアップ中における再発率とIPMN併存膵癌の発生率を検討した．また，それらの患者の臨床所見についても検討した． 【結果】134例のIPMNのうち56例（41.8％）が良性，78例（58.2％）が悪性であった．経過観察期間中央値は29カ月であった．33例（24.6％）に対して，造影剤増強コンピュータ断層撮影法（contrast-enhanced computed tomography：CE-CT）にEUSを併用しフォローアップを行った．一方，101例（75.4％）はCE-CTのみによりフォローアップを行った．再発は13例（9.7％）に認め，うち５例が膵内再発，８例が膵外転移であった．１例において，拡張した主膵管内における造影効果のある壁在結節がEUSのみで描出された．２例において，フォローアップ中にIPMN併存膵癌が発生した．それらは小病変であり，CH-EUSでは検出されたが，CE-CTでは検出されなかった．うち１例においては，EUSでは腫瘍が不明瞭であり，CH-EUSが腫瘍の描出に有用であった． 【結語】IPMN切除後フォローアップにEUSを加えることが有用であることが示唆された．

BACKGROUND AND AIM: When endoscopic retrograde cholangiopancreatography (ERCP) fails in patients with malignant distal biliary obstruction, endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) is an alternative. It has high technical and clinical success rates, but also has high adverse event rates. This prospective cohort study was aimed to evaluate the clinical efficacy and safety of EUS-CDS with our newly developed partially covered self-expandable metal stent with a thin delivery system. METHODS: Patients consisted of all consecutive patients in three tertiary referral centers with unresectable malignant distal obstruction in whom ERCP failed and in whom EUS-CDS with the thin delivery system was selected as the second-line approach. Rates of clinical success, technical success, technical success in cases not requiring fistulous tract dilation, adverse events, and stent dysfunction were determined. RESULTS: In the 20 patients, technical and clinical success rates were 95.0% (19/20) and 100% (19/19), respectively. In 31.6% (6/19), the delivery system was successfully inserted into the bile duct without requiring a fistulous-tract dilatation device. These patients had significantly shorter procedure times than patients requiring fistulous-tract dilatation (12.7 ± 3.1 vs 23.2 ± 2.1 min; P < 0.01). One patient (5.0%) who required fistulous dilation had an adverse event, which was managed conservatively. There were no procedure-related deaths. During follow up, four patients (21.1%) developed stent dysfunction. Reintervention was successful in all cases. CONCLUSIONS: The EUS-CDS approach had 95% technical and 100% clinical success rates, with adverse events reported in 5% of cases. EUS-CDS may become safer if efforts are made to avoid the dilation step (UMIN 000023938).

Hepatocellular carcinoma (HCC) causes one of the most frequent cancer-related deaths; an HCC subset shows rapid progression that affects survival. We clarify molecular features of aggressive HCC, and establish a molecular scoring system that predicts metastasis after curative treatment. In total, 125 HCCs were examined for TP53, CTNNB1, and TERT promoter mutation, methylation of 8 tumor suppressor genes, and 3 repetitive DNA sequences to estimate promoter hypermethylation and global hypomethylation. A fractional allelic loss (FAL) was calculated to represent chromosomal instability through microsatellite analysis. Molecular subclasses were determined using corresponding and hierarchical clustering analyses. Next, twenty-five HCC patients who underwent liver transplantation were analyzed for associations between molecular characteristics and metastatic recurrence; survival analyses were validated using a publicly available dataset of 376 HCC cases from the Cancer Genome Atlas (TCGA). An HCC subtype characterized by TP53 mutation, high FAL, and global hypomethylation was associated with aggressive tumor characteristics, like vascular invasion; CTNNB1 mutation was a feature of the less-progressive phenotype. A number of molecular risk factors, including TP53 mutation, high FAL, significant global hypomethylation, and absence of CTNNB1 mutation, were noted to predict shorter recurrence-free survival in patients who underwent liver transplantation (p = 0.0090 by log-rank test). These findings were validated in a cohort of resected HCC cases from TCGA (p = 0.0076). We concluded that molecular risks determined by common genetic and epigenetic alterations could predict metastatic recurrence after curative treatments, and could be a marker for considering systemic therapy for HCC patients.

Neurilemmomas are benign tumors arising from the sheaths of peripheral nerves. They appear rarely in the abdominal cavity. We herein report an 80-year-old man with a multilocular cystic neurilemmoma mimicking a liver lesion. Preoperative images showed a lesion in the porta hepatis. Although a preoperative diagnosis was difficult, surgery was undertaken because of the possibility of malignancy. Histologically, the tumor consisted of spindle-shaped cells with positivity for S-100 protein. The final diagnosis was a neurilemmoma. Porta hepatic neurilemmomas are rare. When we encounter a multilocular cystic lesion of the liver, neurilemmoma should be considered in the differential diagnosis.

【背景と目的】孤立性胆嚢病変の鑑別診断は課題が残されている．本研究の目的は，胆嚢孤立性病変に対する造影ハーモニックEUS（CH-EUS）の有用性を評価すること． 【方法】2007年３月から2014年２月までの間に，孤立性胆嚢病変を有する125人の患者に対してCH-EUSを施行し，レトロスペクティブにCH-EUSの有用性を検討した．はじめに，胆嚢病変と胆泥の鑑別診断能に関して，通常のBモードEUS（FB-EUS）とCH-EUSを比較検討した．その後，良悪性鑑別に対する診断能を両検査間で比較検討した．CH-EUSのVascular imageおよびPerfusion imageにおける血流パターンを５人の医師によるブラインドリーディングにて評価した． 【結果】胆嚢病変と胆泥の鑑別診断能に関して，FB-EUSの感度は82％，特異度は100％，正診率は95％であった．一方，CH-EUSの感度は100％，特異度は99％，正診率は99％であった．良悪性鑑別に関して，腫瘍の大きさあるいは形状に基づいて診断した場合のFB-EUSの診断感度は61-87％，特異度は71-88％，正診率は74-86％であった．CH-EUSにてVascular imageにおけるirregular vessel patternあるいはPerfusion imageにおけるheterogeneous enhancementを悪性所見とした場合の診断感度は90％，特異度は98％，正診率は96％であり，FB-EUSの診断能と比較し有意に良好であった． 【結語】CH-EUSは，孤立性胆嚢病変の鑑別診断において有用である．

膵・胆管合流異常に合併した共通管内乳頭状腫瘍の1例を報告する．症例は75歳の男性で，6か月間に2度の急性膵炎を発症し保存的加療で軽快した．急性膵炎の原因精査および加療目的で当院へ紹介となった．ERCPでは膵・胆管合流異常を認め，共通管内に7 mmの結節様陰影欠損像を認めた．上部内視鏡検査では乳頭部からの粘液排出は認めず，超音波内視鏡検査では共通管内に乳頭状の腫瘍が描出された．造影CTでは膵頭部に拡張した共通管と内部に増強効果を持つ8 mmの腫瘤を認めた．尾側の主膵管の拡張は認めなかった．膵・胆管合流異常に合併した共通管内乳頭状腫瘍と診断し，亜全胃温存膵頭十二指腸切除術を施行した．病理肉眼所見では共通管内に発育する有茎性の乳頭状腫瘍で，組織像は管状構造増生を主体とする腺腫であった．免疫組織学的染色ではMUC1，MUC2陰性，MUC5AC陽性で胃型腺腫と最終診断した．

症例は73歳男性．膵体部腫瘤の精査目的で入院した．造影CTでは尾側膵管の拡張を伴う境界明瞭な30mmの乏血性腫瘤であった．EUSでは境界が明瞭，辺縁はやや不整で，内部エコー均一な低エコー腫瘤として描出された．膵神経内分泌癌が疑われたが，通常型膵管癌との鑑別が困難であった．同腫瘤に対してEUS-FNAを行い，小細胞型神経内分泌癌と診断した．MRIで肝内に多発する結節を認めたため，多発肝転移を伴う膵神経内分泌癌と診断し，Irinotecan＋Cisplatinのレジメンで化学療法を行った．原疾患の進行のため，化学療法開始より6ヶ月後に永眠された．

【目的】内視鏡的乳頭切除術（Endoscopic Papillectomy：EP）に関連した出血に対する，有効で安全な止血法を明らかにする．【方法】EPを行った24例中，偶発症として出血を認め内視鏡的止血術を行なった13例をretrospectiveに検討した．【結果】出血時期はEP当日9例，翌日3例，翌々日1例で，初回止血法は，アルゴンプラズマ凝固法（APC）2例，Clip法3例，エピネフリン加高張食塩水局注法（HSE）2例，これらの併用が6例であった．13例中4例で再出血を認め，そのうち1例は仮性動脈瘤出血を来し動脈塞栓術を要したが，他は再度内視鏡的止血術を行い止血成功し得た．止血処置に伴う偶発症として5例に膵炎を認め，HSE併用例で多く認められた．【結論】止血効果はAPC併用例に比べClipやHSE併用例で良好であったが，HSE併用例では膵炎に注意が必要である．

57歳男性．両下腿浮腫と腹部膨満感を主訴に受診し，上部消化管内視鏡（以下EGD）およびCT検査で4型進行胃癌が疑われたが胃粘膜の生検，周囲リンパ節のEUS-FNA（fine needle aspiration）では悪性所見を認めなかった．一方で著明な低蛋白血症を認めていたことより蛋白漏出シンチグラフィーを施行したところ消化管からの漏出を確認できた．大腸内視鏡（以下CS）上大腸粘膜に異常は認めなかったが，回腸から直腸すべての生検標本に好酸球の浸潤を認め，好酸球性胃腸炎に伴う蛋白漏出性胃腸症と診断した．

胆嚢ポリープとは，胆嚢内腔に隆起する20 mm程度までの病変の総称で，上皮性か非上皮性か，良性か悪性かは問わない．多くは治療不要なコレステロールポリープであるが，癌・腺腫も含まれ鑑別が必要である．診断には腹部超音波検査，超音波内視鏡検査が有用であるが，画像のみの診断確定は困難である．過去の文献から，10 mm以上，広基性，充実性低エコーを呈するものは癌・腺腫の可能性が高く胆嚢摘出術が推奨される．また，増大傾向を認めるものも癌・腺腫の可能性があり経過観察も重要である．特に初めて発見された胆嚢ポリープは10 mm以下でも初回は慎重に3～6カ月後の経過観察とし，数年間変化がなければ1～2年毎とすることが望ましい．

要旨：症例は76歳，男性．主訴は黄疸．近医にて閉塞性黄疸のためERCP施行され，上部胆管から肝門部胆管にかけての狭窄を認めた．この際の細胞診はclass IIIであったものの肝門部胆管癌が疑われ，精査加療目的で当院紹介となった．当院で行ったCT，MRIで同部位に腫瘤を認め，末梢の胆管拡張を認めた．PET-CTにおいても同部位はFDGの取り込みを認めた．当院で再度施行したERCP下の胆管擦過細胞診にてclass V，IDUSにおいても狭窄部では周囲に浸潤するような腫瘤様構造を呈していた．以上の結果から肝門部胆管癌と診断し，肝右葉切除術，胆管切除術及び胆道再建術を施行した．しかし，切除後の病理組織学的検査では，胆管周囲に密なIgG4陽性形質細胞浸潤を伴う線維増生を認めIgG4関連硬化性胆管炎と診断された．

Interventional EUS治療は長い年月を経て，大きくその可能性を広げ，現在臨床で行われるものとして多くの治療手技が存在する．さらに近年の専用スコープ・デバイスの機器開発は手技の難易度を下げ，安全性を向上させ，Interventional EUS治療を以前よりも偶発症が少ない安全なものに進化させている．一方で教育の問題，保険適応といった問題は解決しておらず，さらに安全で簡便な治療となるためには，今後も従来の治療（ERCPや手術）との比較検討を行いながら，慎重な手技施行を心掛け，患者に最も貢献できるInterventional EUS治療は何か，を追求し続けていく姿勢が求められる．

【目的】改正された電離放射線障害防止規則（2020年4月）では，眼の水晶体の等価線量限度が「5年で100 mSv，なおかつ1年で50 mSv」に引き下げられた．医療部門での職業被ばくを減らす必要がある．この研究の目的は，X線診療室での散乱線量を個人線量当量として測定し，内視鏡的逆行性胆管膵管造影（ERCP）検査における等価線量限度との比較を容易にすることである．【方法】散乱線量は，X線診療室に格子状に配置された放射線測定器によって測定した．線量率は，X線管の周りから患者まで伸びる防護クロス（0.25 mm Pb当量）を使用した場合としない場合で測定した．【結果】ERCPを実施する術者の立ち位置での最大線量率は，地面から150 cmで2.9 mSv/h（3 mm線量当量率）であった．防護クロスを使用しない場合の眼の水晶体の等価線量限度を遵守するためのERCP件数は28件/年であった．【結語】本研究結果はX線診療室内の個人線量当量測定が眼の水晶体の等価線量限度との比較を容易にする可能性を示唆した．

急性胆管炎の死亡率は2.7％と報告され，初期対応を誤れば致死的な経過となる可能性がある病態である．急性胆管炎・胆囊炎診療ガイドライン2018（Tokyo Guidelines 18）には重症度別の急性胆管炎治療が記載されているが，中等症もしくは重症と診断される急性胆管炎には，緊急胆道ドレナージが推奨される．ドレナージ方法にはendoscopic biliary drainage，percutaneous transhepatic biliary drainageがあり，症例に応じた選択が求められる．今後デバイスの改良によりEUS-guided biliary drainageが代替え治療になる可能性はあるが，どのドレナージを選択したとしても，それぞれの特徴，長所・短所，手技内容を十分に理解した上で慎重に行うことには変わりはない．

膵癌早期診断研究会が主導して行った，早期診断された膵癌の実態調査について報告する．40例のStage 0膵癌と119例のStage I膵癌が集積された．膵癌全体に占めるStage 0膵癌とStage I膵癌の割合は約2%であり，Stage 0膵癌は0.6%であった．症状を認めたために医療機関を受診した症例は38例（23.9%）と少なかったのに対して，検診にて異常を指摘され受診した症例は27例（17.0%），他疾患の経過観察中に異常を指摘された症例は85例（53.5%）と無症状で医療機関を受診した症例が多かった．検診にて異常を指摘された27例中，膵管拡張を指摘された症例が19例と画像における副所見の指摘から精査を行った症例が多かった．術前の病理診断では，超音波内視鏡下穿刺吸引法を用いた症例（30.8%）と比較して，内視鏡的逆行性胆管膵管造影下にて病理検体を採取した症例（77.8％）が多かった．予後は良好であったが，14.5%の症例で術後の残膵に膵癌が新たに発生した．今回の調査が，膵癌の早期発見ならびに予後改善に寄与をすることが期待される．

要旨：症例は76歳，男性．主訴は黄疸．近医にて閉塞性黄疸のためERCP施行され，上部胆管から肝門部胆管にかけての狭窄を認めた．この際の細胞診はclass IIIであったものの肝門部胆管癌が疑われ，精査加療目的で当院紹介となった．当院で行ったCT，MRIで同部位に腫瘤を認め，末梢の胆管拡張を認めた．PET-CTにおいても同部位はFDGの取り込みを認めた．当院で再度施行したERCP下の胆管擦過細胞診にてclass V，IDUSにおいても狭窄部では周囲に浸潤するような腫瘤様構造を呈していた．以上の結果から肝門部胆管癌と診断し，肝右葉切除術，胆管切除術及び胆道再建術を施行した．しかし，切除後の病理組織学的検査では，胆管周囲に密なIgG4陽性形質細胞浸潤を伴う線維増生を認めIgG4関連硬化性胆管炎と診断された．

本研究は消化器内科領域における透視下内視鏡手技を使用される放射線被ばく線量により高被ばく手技、中等度被ばく手技、低被ばく手技とグレーディングすることを研究目的の主としている。透視下内視鏡手技は多岐に渡り、各施設で放射線の使用状況も異なるため、単施設での測定は大きなバイアスが発生するため、全国多施設での測定が必要である。本研究責任者の竹中完は全国多施設前向き放射線線量測定を行うために研究グループ（REX-GI group）を発足し、さまざまな透視下内視鏡手技の放射線被ばく線量測定を行い、グループとして国内外の学会発表、英文論文作成を行ってきた。2023年度は本研究に関連する消化器内科領域の透視下手技における被ばく防護に関する英文論文が4本（すべて査読あり、採択ジャーナル：JGH Open,Sci Rep, Br J Radiol, DEN Open）採択された。また米国消化器病週間(DDW2023)、第103回日本消化器内視鏡学会総会において上記内容を学会発表した。 本研究は胆膵疾患（膵癌・胆道癌・急性膵炎・慢性膵炎・膵嚢胞性疾患・胆石等）に対する透視下内視鏡手技における使用放射線被ばく線量測定を全国多施設で行うことが必須であるが、上述のREX-GIにて測定は終えており、一万を超えるデータを取得している。現在解析を行っているが、その中で実際に手技を行う医療従事者の放射線被ばくの現状も明らかにする必要性が浮上し、測定を検討している。測定に際しては各施設で放射線の使用方法、放射線被ばく対策方法が異なるため、研究責任者が各施設を訪問し、現状確認する必要があるがコロナ感染症による施設規制によって訪問規制がかかっていた。2024年度は各施設規制が緩和しているため早々に測定を開始できる見込みである。

本研究は各国の医療に用いられる放射線の使用基準に消化器領域の透視下医療処置の記載がほとんどされていないのは、信頼度の高い実際の被ばく量データが存在しないためであり、各透視下処置における、装置から出力される放射線量、患者・医療従事者の被ばく量を明らかにすることは、現在世に存在しない信頼度の高い情報を得られるのみではなく、「消化器領域のさまざまな透視下処置における被ばく量の基準値を定めDRL設定に繋げる」こと、消化器領域のみならず、透視下医療処置全般に関する被ばく量の基準作りにまで繋がることが可能になると考え立案した。唯一の被ばく国として放射線被ばくに関心の高い本邦において、世界に先駆けて、特に消化器領域の透視下医療処置に関する放射線被ばく量の基準を作成し、世界に発信することを目的に立案した。 「実臨床での透視下手技における患者と医療従事者の被ばく線量集計・解析」については当院における患者への透視下内視鏡手技における被ばく線量測定を行い、その数値は十分に防護対策をとらなければ基準値を容易に超える値であることが判明した。この内容は消化器病学会誌の速報に取り上げられ報告し、日本中の消化器内科医の被ばく防護意識改善に寄与したことが予想される。