佐藤　徹 （サトウ　テツ）

コミュニケーション情報 byコメンテータガイド

• コメント

  これまで培ってきた知識、技術、経験を活かし、一例一例、わかりやすい説明と丁寧な脳血管内治療（カテーテル治療）を提供して、患者さんの満足につながるよう努めます。

研究者情報

学位

• 博士（医学）（2004年01月 京都大学）

ホームページURL

https://jglobal.jst.go.jp/detail?JGLOBAL_ID=202201009849704263

科研費研究者番号

• 40362488

J-Global ID

• 202201009849704263

研究キーワード

• 脳血管内治療   

現在の研究分野（キーワード）

これまで培ってきた知識、技術、経験を活かし、一例一例、わかりやすい説明と丁寧な脳血管内治療（カテーテル治療）を提供して、患者さんの満足につながるよう努めます。

所属学協会

• 日本脳神経血管内治療学会   日本脳神経外科学会   

研究活動情報

論文

• Relation between duration of dual antiplatelet therapy and risk of ischemic stroke after stent-assisted treatment of cerebral aneurysm (DAPTS ACE-registry).

  Tomohiko Ozaki; Hiroshi Yamagami; Masafumi Morimoto; Hirotoshi Imamura; Taketo Hatano; Hidenori Oishi; Koichi Haraguchi; Shinichi Yoshimura; Tetsu Satow; Kenji Sugiu; Koji Iihara; Yuji Matsumaru; Mikito Hayakawa; Yasushi Matsumoto; Chiaki Sakai; Susumu Miyamoto; Kazuo Kitagawa; Tatsuo Kagimura; Nobuyuki Sakai

  Journal of neurointerventional surgery 2023年07月 

  BACKGROUND: The optimal duration of dual antiplatelet therapy (DAPT) in patients with cerebral aneurysm who undergo stent-assisted coil embolization (SACE) has not been established. We aimed to clarify the association between duration of DAPT and incidence of ischemic stroke in patients with cerebral aneurysm. METHODS: We registered patients with cerebral aneurysm who underwent SACE in 27 hospitals in Japan. Those treated with DAPT (aspirin and clopidogrel) were eligible for inclusion in a previously reported randomized control trial (RCT). Patients who were ineligible or refused to participate to the RCT were followed-up for 15 months after SACE as the non-RCT cohort. Our study examined both the RCT and non-RCT cohorts. The primary and secondary outcomes were ischemic stroke and hemorrhagic events. RESULTS: Among the 313 patients registered, 296 were included for analysis (of these, 136 were RCT patients and 160 were non-RCT patients). Patients who were treated with DAPT for more than 6 months (n=191) were classified as the long-term DAPT group. Those treated less than 6 months (n=105) were classified as the short-term group. The incidence of ischemic stroke did not significantly differ between the long-term group (2.5 per 100 person-years) and the short-term group (3.2 per 100 person-years); nor did incidence of hemorrhagic events (0.8 and 3.2 per 100 person-years, respectively). The period of DAPT was not significantly associated with incidence rates of ischemic stroke or hemorrhagic events. CONCLUSIONS: Duration of DAPT was not associated with the incidence of ischemic stroke in the first 15 months after SACE.
• Sequential detection rates of intramural hematoma for diagnosing spontaneous intracranial artery dissection.

  Satoshi Hosoki; Mayumi Fukuda-Doi; Kaori Miwa; Sohei Yoshimura; Yoshiaki Morita; Tetsuya Chiba; Kotaro Noda; Yoshitaka Yamaguchi; Hajime Ikenouchi; Naoki Makita; Tadataka Mizoguchi; Yuki Nakamura; Tetsu Satow; Hiroharu Kataoka; Kazunori Toyoda; Masafumi Ihara; Masatoshi Koga

  European journal of neurology 30 5 1320 - 1326 2023年05月 

  BACKGROUND AND PURPOSE: Spontaneous intracranial artery dissection (IAD) can be definitively diagnosed by detecting intramural hematoma (IMH) on arterial wall imaging. However, evidence of a time-dependent natural history for the development of radiological findings is lacking. Therefore, this study aimed to determine when imaging detects IAD. METHODS: We obtained data from our cohort databases between March 2011 and August 2018 on consecutive patients who had definite, probable, or possible IAD based on the multidisciplinary expert consensus criteria. We assessed IMH on initial and follow-up high-resolution three-dimensional T1-weighted imaging (HR-3D-T1WI). We retrospectively investigated the association between IMH detection and days from symptom onset to initial HR-3D-T1WI and compared the IMH detection rate with other definitive diagnostic arterial dissection findings. RESULTS: We analyzed 106 patients (mean age = 51 ± 13 years, 31 women) with at least initial HR-3D-T1WI data. The final diagnoses were definite, probable, and possible IAD in 83, 18, and 5 patients, respectively. IMHs were observed in 63 patients (59%, 95% confidence interval [CI] = 49%-69%). Overall IMH detection rate was 55% (95% CI = 45%-64%), 20% (95% CI = 3%-60%), 40% (95% CI = 21%-64%), and 50% (95% CI = 37%-63%) on the initial HR-3D-T1WI and Days 3, 7, and 13, respectively. Among 68 patients evaluated with digital subtraction angiography and HR-3D-T1WI, IMH was confirmed more frequently than other definitive diagnostic arterial dissection findings. CONCLUSIONS: The overall IMH detection rate on HR-3D-T1WI was >50% and peaked in 1-2 weeks. IMH was a frequently detectable finding for the diagnosis of IAD compared to other radiological findings.
• Short- versus long-term Dual AntiPlatelet Therapy for Stent-Assisted treatment of CErebral aneurysm (DAPTS ACE): a multicenter, open-label, randomized clinical trial.

  Tomohiko Ozaki; Hiroshi Yamagami; Masafumi Morimoto; Taketo Hatano; Hidenori Oishi; Koichi Haraguchi; Shinichi Yoshimura; Kenji Sugiu; Koji Iihara; Yuji Matsumaru; Yasushi Matsumoto; Tetsu Satow; Mikito Hayakawa; Chiaki Sakai; Susumu Miyamoto; Kazuo Kitagawa; Takashi Daimon; Tatsuo Kagimura; Nobuyuki Sakai

  Journal of neurointerventional surgery 2023年04月 

  BACKGROUND: The optimal duration of dual antiplatelet therapy (DAPT) after stent-assisted coil embolization (SACE) for cerebral aneurysm remains uncertain. This randomized trial of short- versus long-term Dual AntiPlatelet Therapy for Stent-Assisted treatment of CErebral aneurysm (DAPTS ACE) aimed to clarify whether long-term DAPT can reduce the occurrence of ischemic stroke in patients with cerebral aneurysms treated by SACE compared with short-term DAPT. METHODS: Patients treated for cerebral aneurysm with SACE were enrolled from 17 hospitals in Japan. Patients were enrolled within 30 days after SACE and assigned in a 1:1 ratio to receive long-term (12 months) or short-term (3 months) DAPT with aspirin and clopidogrel. Randomization was performed centrally through a web-based system. The primary outcome was the time to ischemic stroke event during 3 to 12 months after SACE. This trial was registered with the Japan Registry of Clinical Trials (jRCTs051180141). RESULTS: A total of 142 patients were recruited from November 4, 2016 to January 7, 2019. Among them, 65 and 68 patients assigned to the long- and short-term DAPT groups, respectively, were included in the full analysis set. Ischemic stroke occurred in no patients in the long-term DAPT group and in one patient in the short-term DAPT group. The incidence rate did not differ between the groups (0.0 vs 2.1/100 person-years; log rank test, P=0.33). CONCLUSIONS: In this multicenter randomized controlled trial, there was not a statistically significant difference in the rate of ischemic strokes between long- and short-term DAPT.
• [Carotid Artery Stenosis:Indications and Outcomes].

  Tetsu Satow

  No shinkei geka. Neurological surgery 51 2 295 - 304 2023年03月 

  Carotid artery stenting(CAS)has emerged as a less invasive alternative to carotid endarterectomy(CEA), the standard surgical treatment for carotid artery stenosis. Major international randomized control trials(RCTs)have demonstrated its non-inferiority to CEA, and it is now recommended in the Japanese stroke treatment guidelines for both symptomatic and asymptomatic severe stenotic lesions. To ensure safety, it is essential to use an embolic protection device to prevent ischemic complications and maintain the quality of physicians proficient in both techniques and devices. In Japan, these two essentials are guaranteed with the aid of a board certification system by the Japanese Society for Neuroendovascular Therapy. Furthermore, preprocedural carotid plaque evaluation using non-invasive methods such as ultrasonography and magnetic resonance imaging to detect vulnerable plaques, which are considered at high risk for embolic complications, is frequently performed, thereby determining therapeutic indications to avoid adverse events. Thus, the results of CAS in Japan are far superior to those of RCT abroad, making this procedure the first-line therapy for carotid revascularization for decades.
• Stent Retriever or Aspiration Catheter Alone vs Their Combination as the First-Line Thrombectomy in Acute Stroke.

  Tsuyoshi Ohta; Kanta Tanaka; Junpei Koge; Takeshi Yoshimoto; Yuji Kushi; Masayuki Shiozawa; Manabu Inoue; Tetsu Satow; Koji Iihara; Masafumi Ihara; Masatoshi Koga; Kazunori Toyoda; Hiroharu Kataoka

  Neurosurgery 92 1 159 - 166 2023年01月 

  BACKGROUND: The single-device simplicity for mechanical thrombectomy (MT) is now challenged by the complementary efficacy of dual-device first-line with a stent retriever and an aspiration catheter. OBJECTIVE: To compare the outcomes after MT initiated with a single device vs dual devices in acute anterior circulation large vessel occlusion. METHODS: Patients who underwent MT for acute internal carotid artery (ICA) or M1 occlusion between 2015 and 2020 were retrospectively analyzed. We divided patients into 2 groups: single-device first-line, defined as patients who underwent first-device pass with either a stent retriever or aspiration catheter, and dual-device first-line, defined as first-device pass with both devices. RESULTS: One hundred forty-one patients were in the single-device group, and 119 were in the dual-device group. In the dual-device group, coiling or kinking of the extracranial ICA was more frequent ( P = .07) and the guide catheters were less frequently navigated to the ICA ( P < .001). 37% of the single-device group was converted to dual-device use. The proportions of mTICI ≥ 2c after the first pass were similar (33% vs 32%. adjusted odds ratio 0.91, 95% CI 0.51-1.62). An mRS score of 0 to 2 at 3 months was achieved similarly (53% vs 48%, P = .46). The total cost for thrombectomy devices was lower in the single-device group ( P < .001). CONCLUSION: The proportions of first-pass mTICI ≥ 2c were not different between the 2 groups with similar functional outcomes, although the dual-device group more likely to have unfavorable vascular conditions.
• Aspect Ratio Is Associated with Recanalization after Coiling of Unruptured Intracranial Aneurysms.

  Takeshi Hara; Tetsu Satow; Eika Hamano; Naoki Hashimura; Masatake Sumi; Taichi Ikedo; Tsuyoshi Ohta; Jun C Takahashi; Hiroharu Kataoka

  Neurologia medico-chirurgica 62 8 377 - 383 2022年08月 

  The rate of recanalization after coil embolization for unruptured intracranial aneurysms (UIAs) is reported to occur around 11.3%-49%. This study aims to investigate the factors that influence the recanalization after coil embolization for UIAs in our institution. We retrospectively investigated 307 UIAs in 296 patients treated at our institution between April 2004 and December 2016. The stent-used cases were excluded. Cerebral angiography and 3D time-of-flight magnetic resonance angiography (TOF MRA) were used for evaluation of the postoperative occlusion status. Volume embolization ratio (VER), aneurysmal size, neck width, and aspect ratio (AR) were compared between the recanalized and non-recanalized groups. The mean follow-up period ranged from 6 to 172 months (mean: 79.0 ± 39.8 months). Recanalization was noted in 78 (25.4%) aneurysms, and 19 (6.2%) aneurysms required retreatment. There was no aneurysmal rupture during the follow-up period. Univariate analysis showed that the aneurysm size (p < 0.001), neck width (p < 0.001), AR (p = 0.003), and VER (p = 0.012) were associated with recanalization. Multivariate logistic regression analysis showed that the AR (p =0.004) and VER (p =0.015) were significant predictors of recanalization. To summarize, a higher AR and a lower VER could lead to recanalization after coil embolization of UIAs. Careful follow-up is required for coiled aneurysms with these features.
• Internal Carotid Artery Tortuosity: Impact on Mechanical Thrombectomy.

  Junpei Koge; Kanta Tanaka; Takeshi Yoshimoto; Masayuki Shiozawa; Yuji Kushi; Tsuyoshi Ohta; Tetsu Satow; Hiroharu Kataoka; Masafumi Ihara; Masatoshi Koga; Noriko Isobe; Kazunori Toyoda

  Stroke 53 8 2458 - 2467 2022年08月 

  BACKGROUND: Although tortuosity of the internal carotid artery (ICA) can pose a significant challenge when performing mechanical thrombectomy, few studies have examined the impact of ICA tortuosity on mechanical thrombectomy outcomes. METHODS: In a registry-based hospital cohort, consecutive patients with anterior circulation stroke in whom mechanical thrombectomy was attempted were divided into 2 groups: those with tortuosity in the extracranial or cavernous ICA (tortuous group) and those without (nontortuous group). The extracranial ICA tortuosity was defined as the presence of coiling or kinking. The cavernous ICA tortuosity was defined by the posterior deflection of the posterior genu or the shape resembling Simmons-type catheter. Outcomes included first pass effect (FPE; extended Thrombolysis in Cerebral Infarction score 2c/3 after first pass), favorable outcome (3-month modified Rankin Scale score of 0-2), and intracranial hemorrhage. RESULTS: Of 370 patients, 124 were in the tortuous group (extracranial ICA tortuosity, 35; cavernous ICA tortuosity, 70; tortuosity at both sites, 19). The tortuous group showed a higher proportion of women and atrial fibrillation than the nontortuous group. FPE was less frequently achieved in the tortuous group than the nontortuous group (21% versus 39%; adjusted odds ratio, 0.45 [95% CI, 0.26-0.77]). ICA tortuosity was independently associated with the longer time from puncture to extended Thrombolysis in Cerebral Infarction ≥2b reperfusion (β=23.19 [95% CI, 13.44-32.94]). Favorable outcome was similar between groups (46% versus 48%; P=0.87). Frequencies of any intracranial hemorrhage (54% versus 42%; adjusted odds ratio, 1.61 [95% CI, 1.02-2.53]) and parenchymal hematoma (11% versus 6%; adjusted odds ratio, 2.41 [95% CI, 1.04-5.58]) were higher in the tortuous group. In the tortuous group, the FPE rate was similar in patients who underwent combined stent retriever and contact aspiration thrombectomy and in those who underwent either procedure alone (22% versus 19%; P=0.80). However, in the nontortuous group, the FPE rate was significantly higher in patients who underwent combined stent retriever and contact aspiration (52% versus 35%; P=0.02). CONCLUSIONS: ICA tortuosity was independently associated with reduced likelihood of FPE and increased risk of postmechanical thrombectomy intracranial hemorrhage. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02251665.
• A multicenter prospective registry of Borden type I dural arteriovenous fistula: results of a 3-year follow-up study.

  Hidehisa Nishi; Hiroyuki Ikeda; Akira Ishii; Takayuki Kikuchi; Ichiro Nakahara; Tsuyoshi Ohta; Nobuyuki Sakai; Hirotoshi Imamura; Jun C Takahashi; Tetsu Satow; Tomohisa Okada; Susumu Miyamoto

  Neuroradiology 64 4 795 - 805 2022年04月 

  PURPOSE: Although intracranial dural arteriovenous fistula (DAVF) without retrograde leptomeningeal venous drainage (Borden type I) is reported to have a benign nature, no study has prospectively determined its clinical course. Here, we report a 3-year prospective observational study of Borden type I DAVF. METHODS: From April 2013 to March 2016, consecutive patients with DAVF were screened at 13 study institutions. We collected data on baseline characteristics, clinical symptoms, angiography, and neuroimaging. Patients with Borden type I DAVF received conservative care while palliative intervention was considered when the neurological symptoms were intolerable, and were followed at 6, 12, 24, and 36 months after inclusion. RESULTS: During the study period, 110 patients with intracranial DAVF were screened and 28 patients with Borden type I DAVF were prospectively followed. None of the patients had conversion to higher type of Borden classification or intracranial hemorrhage during follow-up. Five patients showed spontaneous improvement or disappearance of neurological symptoms (5/28, 17.9%), and 5 patients showed a spontaneous decrease or disappearance of shunt flow on imaging during follow-up (5/28, 17.9%). Stenosis or occlusion of the draining sinuses on initial angiography was significantly associated with shunt flow reduction during follow-up (80.0% vs 21.7%, p = 0.02). CONCLUSION: In this 3-year prospective study, patients with Borden type I DAVF showed benign clinical course; none of these patients experienced conversion to higher type of Borden classification or intracranial hemorrhage. The restrictive changes of the draining sinuses at initial diagnosis might be an imaging biomarker for future shunt flow reduction.
• Usefulness of Craniograms in Discriminating Coiled Intracranial Aneurysms Requiring Retreatment.

  Ryuta Yasuda; Tetsu Satow; Naoki Hashimura; Masaki Nishimura; Jun C Takahashi; Hiroharu Kataoka

  Neurologia medico-chirurgica 62 3 118 - 124 2022年03月 

  While endovascular coil embolization has become one of the major therapeutic modalities for intracranial aneurysms, long-term imaging follow-up is required because of the higher rate of retreatment compared with surgical clipping. The purpose of this study was to show the usefulness of craniograms to discriminate coiled intracranial aneurysms that required retreatment. Under the study protocol approved by institutional review board, a retrospective review of the medical record was done regarding coil embolization for intracranial aneurysms performed between January 2014 and December 2018. Coil embolization performed as the initial treatment and followed up for more than 1 year without additional treatment, and those performed as retreatment after the initial coil embolization performed at our institution were recruited. Craniograms obtained just after the initial treatment were compared with those obtained just before the additional treatment in the retreated cases and compared with the latest ones in the non-recurrence cases. Correlation between the morphological changes in the coil mass on the craniograms and retreatments was evaluated. During the study period, 288 coil embolization procedures for intracranial aneurysms were performed. From these, 191 treatments that were followed up for more than 1 year without any additional treatments and 30 retreatments were included. Morphological change of the coil mass was observed in 4 of the 191 non-recurrence treatments and 26 of the 30 retreatments, which was significantly correlated with retreatments (p <0.001). Craniogram was a useful modality in following up the coiled intracranial aneurysms to detect those required retreatments.
• A Pathologically Verified Case of Peripheral Intracranial Aneurysmal Formation With Massively Infiltrating Meningioma Cells.

  Tatsuki Kimura; Taichi Ikedo; Keiko Ohta-Ogo; Eika Hamano; Tsuyoshi Ohta; Hisae Mori; Tetsu Satow; Masatake Sumi; Naoki Hashimura; Takeshi Hara; Koji Shimonaga; Yuji Kushi; Yoshihiko Ikeda; Kinta Hatakeyama; Koji Iihara; Hiroharu Kataoka

  Journal of neuropathology and experimental neurology 81 3 242 - 245 2022年02月
• Mechanical Thrombectomy Beyond 2b Reperfusion: Should We Pursue a Higher Reperfusion Grade after Achievement of 2b?

  Junpei Koge; Kanta Tanaka; Takeshi Yoshimoto; Masayuki Shiozawa; Tsuyoshi Ohta; Tetsu Satow; Hiroharu Kataoka; Masafumi Ihara; Masatoshi Koga; Kazunori Toyoda

  Stroke: Vascular and Interventional Neurology 2022年01月 [査読有り]
  
• A Case of Direct Carotid-Cavernous Fistulae Successfully Treated by Bidirectional Double Catheter Technique: A Technical Note.

  Eika Hamano; Tetsu Satow; Takamitsu Hori; Jun C Takahashi; Hiroharu Kataoka

  Journal of neuroendovascular therapy 16 6 307 - 312 2022年 

  OBJECTIVE: Ruptured carotid-cavernous aneurysms (CCAs) are known to result in direct carotid-cavernous fistula (CCF). Although endovascular treatment is recognized as the first-line treatment for direct CCF, obliteration is sometimes difficult because of the high-flow shunt. In this report, we present a case of a direct CCF treated by the combination of transarterial and transvenous approaches. CASE PRESENTATION: A 57-year-old woman presented with conjunctival chemosis, exophthalmos, and tinnitus. Ophthalmological examination revealed increased intraocular pressure. DSA demonstrated a direct CCF due to a right ruptured CCA with retrograde shunted flow through the superior ophthalmic vein (SOV), superficial middle cerebral vein, basal vein of Rosenthal, and middle temporal vein. Two microcatheters were guided into the shunt segment from the internal carotid artery and SOV. In addition, a balloon catheter was placed at the neck of the aneurysm to assist coiling. Coil embolization for the CCF was performed using two microcatheters in the opposite direction, which enabled compact and tight packing of the shunt segment with only six coils. The CCF was eliminated. Two-year-follow-up MRA revealed no recurrence. CONCLUSION: The bidirectional double catheter technique is a useful approach to obliterate a shunt in a short segment with minimal coils.
• Impact on Clinical Outcomes of Changes in the Practice of Mechanical Thrombectomy due to the COVID-19 Pandemic.

  Tsuyoshi Ohta; Tetsu Satow; Manabu Inoue; Kanta Tanaka; Junpei Koge; Takeshi Yoshimoto; Eika Hamano; Taichi Ikedo; Masatake Sumi; Koji Shimonaga; Yuji Kushi; Hisae Mori; Koji Iihara; Masafumi Ihara; Masatoshi Koga; Kazunori Toyoda; Hiroharu Kataoka

  Journal of neuroendovascular therapy 16 10 498 - 502 2022年 

  OBJECTIVE: To evaluate whether changes in the practice of mechanical thrombectomy could affect the clinical outcomes during the coronavirus disease (COVID-19) pandemic. METHODS: Patients who underwent mechanical thrombectomy from April 2019 to March 2021 for anterior circulation proximal large artery occlusion in our institute were divided into two groups of pre- and post-COVID-19, with April 2020 assumed to be the start of the COVID-19 era with the first declaration of a state of emergency. We compared patient characteristics, proportions of patient selection depending on rapid processing of perfusion and diffusion (RAPID) CT perfusion, outcomes including treatment variables such as time and reperfusion status, and patient independence at 3 months. RESULTS: Data for 112 patients (median age, 79 years; 44 females) were included in the analysis. A total of 50 patients were assigned to the pre-COVID-19 group (45%). More patients were selected with RAPID CT perfusion in the post-COVID-19 compared with the pre-COVID-19 (69% vs. 16%; P <0.001). Treatment details and clinical outcomes did not differ between the groups, including the door-to-puncture time (median [interquartile range], 66 [54-90] min vs. 74 [61-89] min; P = 0.15), proportions of significant reperfusion (82% vs. 87%; P = 0.60), and modified Rankin scale score of ≤2 at 3 months (46% vs. 45%; P >0.99). Multivariate logistic regression analysis for the clinical outcome of modified Rankin scale score of ≤2 at 3 months was performed and included the following factors: age, sex, the onset-to-door time, significant reperfusion, and pre- and post-COVID-19. The treatment period did not influence the outcomes (post-COVID-19 group, odds ratio, 0.79; 95% confidence interval, 0.34-1.85, P = 0.59). CONCLUSION: In the setting of a limited access to emergency MRI during the COVID-19 pandemic, RAPID CT perfusion was performed significantly more often. Changes in the practice of mechanical thrombectomy with the protected code stroke did not bring the different level of treatment and clinical outcomes as before.
• Coiling for Ruptured Aneurysms in the Vasospasm Period: Safety and Efficacy Based on a Propensity Score Analysis.

  Takao Koiso; Tetsu Satow; Eika Hamano; Masaki Nishimura; Jun C Takahashi; Hiroharu Kataoka

  Journal of neuroendovascular therapy 16 3 141 - 146 2022年 

  OBJECTIVE: To evaluate the efficacy and safety of interventional radiology (IVR) for aneurysmal subarachnoid hemorrhage (SAH) later than 3 days after onset. METHODS: A total of 71 patients between 2012 and 2017 who underwent endovascular coiling were divided into two groups according to the timing of treatment: Group E (treated within 3 days after onset) and group D (treated between 4 and 14 days after onset), and the outcomes between two groups were compared. A case-matched study was conducted to minimize the selection bias lying in this cohort. RESULTS: There were 56 (78.9%) and 15 (21.1%) patients in groups E and D, respectively. In group D, all patients arrived at the hospital later than 3 days after onset. The rates of patients with WFNS grade 1, 2, 3 and the presence of vasospasm upon the access route to the targeted aneurysm at the time of IVR were significantly higher in group D than in group E (93.3% vs 60.7%; p = 0.027, 33.3% vs 3.6%; p = 0.0037, respectively). There were no significant differences in the rate of intraprocedural complications, symptomatic vasospasm, delayed cerebral infarction due to vasospasm, retreatment, or modified Rankin Scale (mRS) at discharge. After propensity score matching, there were no significant differences in the outcomes between two groups. CONCLUSION: Prompt coiling for patients with ruptured aneurysms who arrived later than 3 days after onset can be safely performed, even if they had vasospasm upon the access route.
• Mechanical Thrombectomy Up to 24 Hours in Large Vessel Occlusions and Infarct Velocity Assessment.

  Manabu Inoue; Takeshi Yoshimoto; Kanta Tanaka; Junpei Koge; Masayuki Shiozawa; Tatsuya Nishii; Yasutoshi Ohta; Tetsuya Fukuda; Tetsu Satow; Hiroharu Kataoka; Hiroshi Yamagami; Masafumi Ihara; Masatoshi Koga; Michael Mlynash; Gregory W Albers; Kazunori Toyoda

  Journal of the American Heart Association 10 24 e022880  2021年12月 

  Background We retrospectively compared early- (<6 hours) versus late- (6-24 hours) presenting patients using perfusion-weighted imaging selection and evaluated clinical/radiographic outcomes. Methods and Results Large vessel occlusion patients treated with mechanical thrombectomy from August 2017 to July 2020 within 24 hours of onset were retrieved from a single-center database. Perfusion-weighted imaging was analyzed by automated software and final infarct volume was measured semi-automatically within 14 days. The primary end point was good outcome (modified Rankin Scale 0-2 at 90 days). Secondary end points were excellent outcome (modified Rankin Scale 0-1 at 90 days), symptomatic intracranial hemorrhage, and death. Clinical characteristics/radiological values including hypoperfusion volume and infarct growth velocity (baseline volume/onset-to-image time) were compared between the groups. Of 1294 patients, 118 patients were included. The median age was 74 years, baseline National Institutes of Health Stroke Scale score was 14, and core volume was 13 mL. The late-presenting group had more female patients (67% versus 31%, respectively; P=0.001). No statistically significant differences were seen in good outcome (42% versus 53%, respectively; P=0.30), excellent outcome (26% versus 32%, respectively; P=0.51), symptomatic intracranial hemorrhage (6.5% versus 4.6%, respectively; P=0.74), and death (3.2% versus 5.7%, respectively; P=0.58) between the groups. The late-presenting group had more atherothrombotic cerebral infarction (19% versus 6%, respectively; P=0.03), smaller hypoperfusion volume (median: 77 versus 133 mL, respectively; P=0.04), and slower infarct growth velocity (median: 0.6 versus 5.1 mL/h, respectively; P=0.03). Conclusions Patients with early- and late-time windows treated with mechanical thrombectomy by automated perfusion-weighted imaging selection have similar outcomes, comparable with those in randomized trials, but different in infarct growth velocities. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02251665.
• Identifying large ischemic core volume ranges in acute stroke that can benefit from mechanical thrombectomy.

  Takeshi Yoshimoto; Manabu Inoue; Kanta Tanaka; Kodai Kanemaru; Junpei Koge; Masayuki Shiozawa; Naruhiko Kamogawa; Shunsuke Kimura; Tetsuya Chiba; Tetsu Satow; Jun C Takahashi; Kazunori Toyoda; Masatoshi Koga; Masafumi Ihara

  Journal of neurointerventional surgery 13 12 1081 - 1087 2021年12月 

  BACKGROUND: We aimed to identify the large ischemic core (LIC) volume ranges in acute ischemic stroke patients that can benefit from mechanical thrombectomy (MT). METHODS: Consecutive patients within 24 hours of onset of anterior circulation ischemic stroke with large vessel occlusion and ischemic core volumes of 70-300 mL were included from our single-center prospective database from March 2014 to December 2019. Subjects were divided into three groups by baseline ischemic core volume (A: 70-100 mL; B: 101-130 mL; C: >130 mL). We compared modified Rankin Scale (mRS) score 0-2 at 3 months and parenchymal hematoma between patients receiving MT and standard medical treatment (SMT), and determined clinically treatable core volume ranges for MT. RESULTS: Of 157 patients (86 women; median age, 81 years; median ischemic core volume, 123 mL), 49 patients underwent MT. In Group A (n=52), MT patients (n=31) showed a higher proportion of mRS 0-2 at 3 months (52% vs 5%, P<0.05) versus SMT, respectively. Group B (n=36) MT patients (n=14) also had a higher proportion of mRS 0-2 at 3 months (29% vs 9%, P=0.13) versus SMT, respectively. In Group C (n=69), only four patients received MT. The 95% confidence intervals for the probability of mRS 0-2 at 3 months in patients with MT (n=49) versus SMT (n=108) intersected at 120-130 mL. CONCLUSIONS: Ischemic core volumes between 70 and 100 mL may benefit from MT. The treatable upper core limit is approximately 120 mL in selected patients with LIC of 70-300 mL.
• Outcome of Endovascular Therapy Aiming for Single-session Obliteration of Intracranial Dural Arteriovenous Fistulas.

  Taichi Ishiguro; Tetsu Satow; Eika Hamano; Go Ikeda; Hidekazu Chikuie; Naoki Hashimura; Masaki Nishimura; Jun C Takahashi; Hiroharu Kataoka

  Neurologia medico-chirurgica 61 10 563 - 569 2021年10月 

  The goal of dural arteriovenous fistula (dAVF) treatment is obliteration of the arteriovenous shunt and/or retrograde leptomeningeal venous drainage (RLVD). Single-session obliteration could improve symptoms early and reduce risk of neurological sequelae. This study investigated the efficacy and adverse events of endovascular therapy (EVT) aiming for single-session obliteration in dAVF treatment. We retrospectively examined post-treatment arteriovenous shunt status, number of treatments per case, treatment-related complications, and long-term outcome in 92 dAVF patients who underwent initial EVT at our institution. Single-session obliteration was intended in all cases, but a second session was performed in cases of partial shunt occlusion or remaining RLVD. Complete occlusion was achieved in 85 cases (92.4%) after the single session; RLVD was obliterated in 66 of the 67 Borden type II and III cases combined (98.5%). A second session was necessary in seven cases (7.6%). Complete shunt obliteration was eventually achieved in all cases. The average number of treatments was 1.08 per case. dAVF-related stroke and mortality did not occur after the treatment. On the other hand, radiation-induced skin erythema and alopecia, although all symptoms were transient, occurred in 26 cases (28.3%). Over an average 60.2-month follow-up period, recurrence was observed in seven cases (7.6%). Single-session obliteration was successful in 92% of cases. Especially, single-session obliteration of RLVD may contribute to early prevent of future stroke events. However, reducing total radiation dose during each session is an issue of further study.
• [Cerebrovascular imaging to facilitate stroke reperfusion therapy in Japan].

  Masatoshi Koga; Manabu Inoue; Kanta Tanaka; Tetsu Satow; Tetsuya Fukuda; Masafumi Ihara; Ryo Itabashi; Kohsuke Kudo; Hiroshi Yamagami; Kazunori Toyoda

  Rinsho shinkeigaku = Clinical neurology 61 8 517 - 521 2021年08月 

  Imaging diagnosis is essential to perform appropriate reperfusion therapy for acute ischemic stroke. To equally perform reperfusion therapy all over in Japan, it is important to properly facilitate acute imaging evaluation for stroke suspected patients by medical staff not only in stroke-specialized hospitals but also in non-stroke-specialized hospitals. It is unique that CT and MRI are available in most of Japanese hospitals. Even in non-stroke-specialized hospitals, inpatients may suffer from in-hospital stroke. We review statements and recommendation items for a diagnostic imaging to appropriately perform reperfusion therapy based on major clinical trials, stroke guidelines and the current status of acute stroke imaging in Japan.
• Early recurrent ischemic events after mechanical thrombectomy: effect of post-treatment intracranial hemorrhage.

  Junpei Koge; Kanta Tanaka; Takeshi Yoshimoto; Masayuki Shiozawa; Hiroshi Yamagami; Tetsu Satow; Jun C Takahashi; Masafumi Ihara; Masatoshi Koga; Jun-Ichi Kira; Kazunori Toyoda

  Journal of neurology 268 8 2810 - 2820 2021年08月 

  OBJECTIVE: Patients with intracranial hemorrhages (ICH) after mechanical thrombectomy (MT) may have a higher risk of early recurrent embolism (ERE) because of delayed initiation of anticoagulants. We assessed the rate of ischemic events in the early period after MT and the association with post-MT ICH. METHODS: Patients who underwent MT in our institute were retrospectively reviewed. ERE was defined as recurrent ischemic stroke and systemic embolism within 14 days after MT. The association between ERE and parenchymal hematoma (PH) was assessed. Multivariable regression analysis and inverse probability of treatment weighting was used to adjust for differences in baseline characteristics between patients with and without PH. RESULTS: A total of 307 patients (median age, 78 years; female, 47%; median baseline National Institutes of Health Stroke Scale score, 19) were included. ERE was observed in 12 of 307 patients (8 strokes, 4 systemic embolisms; 3.9%). Median time from MT to ERE was 6.5 days (IQR, 3-8 days). PH occurred in 21 patients (6.8%). Median time from MT to initiating oral anticoagulants was longer in patients with PH (8 days) than in those without (3 days) (p < 0.01). In both unweighted and weighted multivariable analysis, PH was significantly associated with an increased risk of ERE (unweighted odds ratio, 10.60; 95% CI, 2.66-42.23; weighted odds ratio, 12.34; 95% CI, 2.49-61.07). CONCLUSIONS: ERE occurred in about 4% of patients after MT. PH after MT was associated with delayed initiation of oral anticoagulants and an increased risk of recurrent ischemic events. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02251665.
• Corrigendum to 'Clinical Trial of the New Stent Retriever Tron FX for both Proximal and Distal Intracranial Large Vessel Occlusions' [Journal of Stroke and Cerebrovascular Diseases, Vol. 30, No. 3 (March), 2021: 105585].

  Hirotoshi Imamura; Nobuyuki Sakai; Hiroshi Yamagami; Tetsu Satow; Yasushi Matsumoto; Keisuke Imai; Shinzo Ota; Nobutaka Horie; Rei Kondo; Yukiko Enomoto; Shinichi Yoshimura; Masaru Hirohata; Masunari Shibata; Yuji Matsumaru; Nobuyuki Ohara; Chiaki Sakai

  Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association 30 7 105689 - 105689 2021年07月
• Clinical Trial of the New Stent Retriever Tron FX for both Proximal and Distal Intracranial Large Vessel Occlusions.

  Hirotoshi Imamura; Nobuyuki Sakai; Hiroshi Yamagami; Tetsu Satow; Yasushi Matsumoto; Keisuke Imai; Shinzo Ota; Nobutaka Horie; Rei Kondo; Yukiko Enomoto; Shinichi Yoshimura; Masaru Hirohata; Masunari Shibata; Yuji Matsumaru; Nobuyuki Ohara; Chiaki Sakai

  Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association 30 3 105585 - 105585 2021年03月 

  BACKGROUND: In all of randomized controlled trials of mechanical thrombectomy, the target vessels were proximal. Herein we report a clinical trial of the Tron FX stent retriever, including the smallest size of 2/15 mm for distal intracranial large vessel occlusion (LVO). OBJECTIVE: Eligible patients presented within 8 h of onset with proximal or distal LVOs, and the Tron FX 4/20 mm or 2/15 mm were used as the first-line device. METHODS: The primary endpoints were rate of modified Thrombolysis in Cerebral Infarction (mTICI) grade 2a-3 immediately after using Tron FX only, and mortality rate 90 d. We compared the outcomes between sizes 4/20 and 2/15 mm. RESULTS: The clinical trial was conducted in 50 cases, of which 44% presented with distal LVO and 15 cases were treated using only Tron FX 2/15 mm. The overall rate of mTICI grade 2a-3 was 80.0% (75.8% with Tron FX 4/20 mm, and 86.7% with 2/15 mm), and a 90-day modified Rankin Scale ≤ 2 or improvement of National Institute of Health Stroke Scale after thrombectomy ≥ 10 was achieved in 66.7% of cases (61.3% with Tron FX 4/20 mm, and 80.0% with 2/15 mm). The overall 90-day mortality rate was 8.0%, and symptomatic intracranial hemorrhage within 24 h occurred in 2.0% of cases. CONCLUSION: In this clinical trial using the Tron FX, which included the size of 2/15 mm for distal LVO, its efficacy was similar and its safety was superior compared with previous studies.
• Blind Exchange With Mini-Pinning Technique Using the Tron Stent Retriever for Middle Cerebral Artery M2 Occlusion Thrombectomy in Acute Ischemic Stroke.

  Takeshi Yoshimoto; Kanta Tanaka; Junpei Koge; Masayuki Shiozawa; Hiroshi Yamagami; Manabu Inoue; Naruhiko Kamogawa; Tetsu Satow; Hiroharu Kataoka; Kazunori Toyoda; Masafumi Ihara; Masatoshi Koga

  Frontiers in neurology 12 667835 - 667835 2021年 

  Introduction: The usefulness of the blind exchange with mini-pinning (BEMP) technique has recently been reported for mechanical thrombectomy in patients with stroke owing to medium vessel occlusion (MeVO). The Tron stent retriever can be delivered and deployed through a 0.0165-inch microcatheter. This retriever has potential as an effective and safe treatment for acute ischemic stroke (AIS) due to occlusion of the M2 segment of the middle cerebral artery (MCA). Here, we report the outcomes of the BEMP technique using Tron stent retrievers for M2 occlusion thrombectomy. Methods: Consecutive patients with AIS owing to M2 occlusion who underwent the BEMP technique using 2 × 15-mm or 4 × 20-mm Tron stent retrievers were included. The technique involves deploying a Tron stent retriever through a 0.0165-inch microcatheter, followed by microcatheter removal and blind navigation of a 3MAX or 4MAX aspiration catheter over the bare Tron delivery wire until the aspiration catheter reaches the clot. A Tron stent retriever is inserted into the aspiration catheter like a cork and subsequently pulled as a unit. We assessed procedural outcomes [first-pass expanded thrombolysis in cerebral infarction (eTICI) score 2c/3 and 2b/2c/3], safety outcomes [symptomatic intracranial hemorrhage (sICH)], and clinical outcomes (good outcome rate defined as modified Rankin Scale score 0-2 at 90 days and mortality at 90 days). Results: Eighteen M2 vessels were treated in 15 patients (six female, median age: 80 years, and median National Institutes of Health Stroke Scale score: 18). The BEMP technique was performed successfully in all cases. Whether to use a 3MAX or 4MAX catheter was determined by considering one of the following target vessels: dominant, non-dominant, or co-dominant M2 (3MAX, n = 9; 4MAX, n = 9). The first-pass eTICI 2c/3 and 2b/2c/3 rates were 47 (7/15) and 60% (9/15), respectively; sICH was not observed. Seven patients (47%) achieved good outcomes, and one patient (7%) died within 90 days. Conclusions: The Tron stent retriever was safely and effectively used in the BEMP technique for acute MCA M2 occlusion and can be combined with a 0.0165-inch microcatheter, which may be useful for treating MeVO, in general.
• Hyperperfusion Syndrome Detected by 15O-Gas Positron Emission Tomography after Clipping of a Large Unruptured Internal Carotid Artery Aneurysm: A Case Report.

  Takao Koiso; Daisuke Maruyama; Eika Hamano; Hisae Mori; Tetsu Satow; Hiroharu Kataoka; Jyoji Nakagawara; Jun C Takahashi

  NMC case report journal 8 1 275 - 279 2021年 

  Cerebral hyperperfusion syndrome (CHS) after surgical clipping for cerebral aneurysm is a rare entity. The authors present a 76-year-old woman with a large left internal carotid-posterior communicating artery aneurysm. After successful clipping with temporary occlusion of the internal carotid artery, the patient exhibited motor aphasia. 15O-gas positron emission tomography (PET) showed extreme elevation of the regional cerebral blood flow (rCBF) along with a mildly decreased regional cerebral metabolic rate for oxygen (rCMRO2) and a remarkable decrease in the oxygen extraction fraction (OEF) in the territory of the ipsilateral superior trunk of the middle cerebral artery. These data indicated local hyperperfusion. She had fully recovered from the aphasia by postoperative day (POD) 18. PET showed normalization of CBF on POD 27. To our knowledge, this is the first case report to show hyperperfusion syndrome, clearly detected by 15O-gas PET, after aneurysmal neck clipping.
• Transvenous Coil-plugging Technique for a Symptomatic Giant Varix Associated with Arteriovenous Malformation.

  Yuji Kushi; Tetsu Satow; Taichi Ikedo; Tsuyoshi Ohta; Takeshi Hara; Jun C Takahashi; Koji Iihara; Hiroharu Kataoka

  NMC case report journal 8 1 479 - 483 2021年 

  In case of symptomatic varix associated with cerebral arteriovenous malformations (AVM), nidus is usually treated with transarterial embolization (TAE). However, TAE is not always possible due to inaccessible nidus. A man in his 40s presented with numbness and clumsiness in the right hand. Magnetic resonance imaging (MRI) and cerebral angiography revealed a giant varix associated with an AVM nidus in the left parietal lobe. The varix severely compressed the postcentral gyrus with edema. The main feeder was occluded, and tiny collateral vessels fed the nidus. After admission, his symptoms deteriorated rapidly due to the enlarging varix. To extirpate the varix, selective transvenous embolization (TVE) of a small compartment, the varix neck, between the varix and the main cortical drainer with coils was performed. After treatment, the thrombosed varix gradually shrank, and his symptoms improved. The transvenous coil-plugging technique is a potential strategy for symptomatic varix with a varix neck.
• Clinical Outcome of Elderly Patients with Subarachnoid Hemorrhage: Validation of Modality Assignment Based on Aneurysmal Morphology and Location.

  Takuma Maeda; Tetsu Satow; Go Ikeda; Eika Hamano; Naoki Hashimura; Takeshi Hara; Masatake Sumi; Masaki Nishimura; Jun C Takahashi

  World neurosurgery 143 e419-e429  2020年11月 

  BACKGROUND: The number of elderly patients with subarachnoid hemorrhage is increasing. Elderly patients have been postulated to benefit more from endovascular coiling, compared with neurosurgical clipping. However, we based our therapeutic modality on the morphology and location of the aneurysms, rather than patients' age or their World Federation of Neurological Surgeons grade. The aim of this study was to investigate the validity of our therapeutic modality over earlier approaches by assessing their clinical outcomes. METHODS: The study sample included 539 patients who underwent surgical procedures between January 2010 and May 2019. Baseline characteristics, aneurysmal morphology and location, surgical and clinical complications, and clinical outcomes were compared between elderly (defined as aged 75 years or older) and young patients. RESULTS: There were 124 elderly patients (23.0%) in the sample. Eighty-five elderly patients (68.5%) received neurosurgical clipping, whereas 67.0% of the young patients (P = 0.827) received neurosurgical clipping. Of the elderly patients who had a poor World Federation of Neurological Surgeons grade, 49.4% and 48.7% underwent neurosurgical clipping and endovascular coiling, respectively (P = 1.000). Elderly patients had fewer favorable outcomes (21.8%) relative to young patients (61.8%; P < 0.001). There were no significant differences in the rate of favorable outcomes between patients undergoing neurosurgical clipping relative to endovascular coiling (21.2% vs. 23.1%; P = 0.818). CONCLUSIONS: Neurosurgical clipping and endovascular coiling yield comparable clinical outcomes in elderly and young patients with subarachnoid hemorrhage. These findings indicate that using a therapeutic modality based on aneurysmal morphology and location may be an effective treatment approach.
• Intracranial arterial stenosis associated with Hashimoto's disease: angiographic features and clinical outcomes.

  Eika Hamano; Masaki Nishimura; Hisae Mori; Tetsu Satow; Jun C Takahashi

  BMC neurology 20 1 345 - 345 2020年09月 

  BACKGROUND: Hashimoto's disease has reportedly been associated with stroke; however, cerebrovascular morphology and clinical course remain poorly documented. The present study aimed to determine the angiographic features and clinical outcomes of intracranial arterial stenosis (IAS) associated with Hashimoto's disease in a retrospective cohort. METHODS: Overall, 107 adult patients with IAS were screened for anti-thyroid antibodies; of these, 26 patients tested positive. The 42 affected hemispheres were classified into subgroups according to the steno-occlusion site and the development of abnormal collateral (moyamoya) vessels. These subgroups were dichotomized into moyamoya vessels positive (MM type) and negative (non-MM type). The initial presentation, IAS progression, and vascular events during the follow-up period were compared. RESULTS: The following sites of stenosis were identified: the bifurcation of the internal carotid artery in 11 (26.2%), M1 or A1 in 29 (69.0%), and more distal (M2-M4/A2-A4) in 2 (4.8%) hemispheres. Further, 17 hemispheres were categorized into the MM type and 25 were classified into the non-MM type. During the follow-up period (mean 2.5 years), IAS progression was identified in 8 (32%) hemispheres of the non-MM type and 0 (0%) hemispheres of the MM type (p = 0.041). Ischemic attacks occurred in 5 (20.0%) hemispheres of the non-MM type (4.6%/year) and 0 hemispheres of the MM type (p = 0.08). Further, 4 (23.5%) hemispheres of the MM type experienced intracerebral hemorrhage, whereas none of the non-MM type hemorrhaged (p = 0.012). CONCLUSIONS: Hashimoto's disease-associated IAS exhibits various angiographic morphologies, resulting in different clinical presentations. Screening for anti-thyroid antibodies and careful management based on vascular morphology appears important in adults with IAS.
• Difference in periventricular anastomosis in child and adult moyamoya disease: a vascular morphology study.

  Jiwook Ryu; Eika Hamano; Masaki Nishimura; Tetsu Satow; Jun C Takahashi

  Acta neurochirurgica 162 6 1333 - 1339 2020年06月 

  BACKGROUNDS: Periventricular anastomosis (PA), which is a novel term for extended collateral vessels in moyamoya disease (MMD), is reportedly associated with a high risk of intracranial hemorrhage in adult patients. The present study aimed to clarify the similarities and the differences in the development of PA between three MMD groups, classified by age at the time of diagnosis and clinical phenotype. METHODS: This study included 232 hemispheres of 132 patients with MMD who underwent surgical revascularization. The subjects were classified into child ischemic (CI) group, adult ischemic (AI) group, and adult hemorrhagic (AH) group. We evaluated the lenticulostriate (LSA), thalamic (THA), choroidal (ChA), anterior choroidal (AChA), and posterior choroidal (PChA) anastomosis as well as the posterior cerebral artery (PCA) involvement. The PA scores and the sums of each grade of LSA, THA, and ChA anastomosis were also calculated in all of the cases. RESULTS: In a multiple comparison test, the PA scores (P < 0.01), LSA (P < 0.01), and ChA anastomosis (P = 0.013) were more prominent in the CI than in the AI group. The PA scores (P < 0.01) and LSA (P = 0.011), ChA (P < 0.01), AChA (P < 0.01), and PChA anastomosis (P = 0.016) were more prominent in the AH group than in the AI group. The CI and AH groups showed similar characteristics except for PCA involvement. After multivariate adjustments using the AI group as a reference group, the PA scores and the positive rates of LSA and ChA anastomosis remained significantly higher in the CI and AH groups. CONCLUSION: The patterns of PA development in the CI and AH groups were similar in that they were more prominent than in the AI group. These findings may contribute to a better understanding of the progression of ischemic and hemorrhagic MMD.
• Factors related to adverse events during endovascular coil embolization for ruptured cerebral aneurysms.

  Hirotoshi Imamura; Nobuyuki Sakai; Tetsu Satow; Koji Iihara

  Journal of neurointerventional surgery 12 6 605 - 609 2020年06月 

  Background and purpose The risk factors for adverse events for example, intraprocedural rupture (IPR), ischemic complication within 24 hours, and rebleeding after endovascular coil embolization for a ruptured cerebral aneurysm remain unclear. The aim of this study was to identify significant associated risk factors. Methods We retrospectively evaluated data from 5358 patients listed on the Japanese Registry of Neuroendovascular Therapy 3 during 2010–2014. Results IPR, ischemic complications, and rebleeding occurred during or after 221 (4.1%), 226 (4.2%), and 63 (1.2%) treatments, respectively. All of the adverse events were significantly associated with the patients’ poor outcomes at 30 days. Multivariate analysis revealed the factors independently related to these adverse events as follows: (1) for IPR: female sex, bifurcation type, <5 mm aneurysm, emergent surgery, local anesthesia, a balloon-assisted technique; (2) for an ischemic complication: poor World Federation World Federation of Neurological Societies (WFNS) grade, wide neck, and stent-assisted technique; (3) for rebleeding: poor WFNS grade, bifurcation type, wide neck, and body filling as the initial result. Conclusions Knowledge of the risk factors of endovascular coil embolization and paying attention to them are essential for patients’ safe treatment and good outcomes.
• Trends in Endovascular Reperfusion Therapy for Acute Stroke after Introduction of Mechanical Thrombectomy Devices: Japanese Registry of NeuroEndovascular Therapy (JR-NET)3.

  Mikito Hayakawa; Yuji Matsumaru; Hiroshi Yamagami; Tetsu Satow; Koji Iihara; Nobuyuki Sakai

  Neurologia medico-chirurgica 60 4 191 - 201 2020年04月 

  In Japan, the era of thrombectomy for acute stroke started when the Merci retriever was approved in 2010 and the Penumbra system in 2011. New-generation Penumbra catheters (MAX series) and stent retrievers were introduced in 2013 and 2014, respectively. The aim of this study was to clarify the general status and trends in endovascular reperfusion therapy for stroke in Japan from 2010 to 2014. We extracted a total of 3705 patients (72.1 ± 12.2 years, 1482 women) from a nationwide study of patients receiving any neuroendovascular treatment, the Japanese Registry of NeuroEndovascular Therapy 3. Reperfusion therapy resulted in a successful reperfusion rate of 59%, and 31% of patients achieved a favorable outcome at 30 days of onset. The frequency of Merci-including procedures increased to 52% in the first half of 2011, but conversely decreased to 1% in the second half of 2014. The frequency of Penumbra-including procedures increased from 18% in the second half of 2011 to 67% in the first half of 2014, decreasing to 38% in the second half of 2014. The reperfusion rate and 30-day clinical outcomes remained almost unchanged until June 2013, and started to improve thereafter, coincident with the introduction and spread of newer-generation devices. The rate of successful reperfusion reached 71-76%, and 36-38% of patients achieved a favorable outcome in 2014. After multivariate adjustment for preprocedure variables, the calendar period from 2013 to 2014 was significantly associated with improvement in reperfusion rates and clinical outcomes.
• Coil Embolization for Unruptured Intracranial Aneurysms at the Dawn of Stent Era: Results of the Japanese Registry of Neuroendovascular Therapy (JR-NET) 3.

  Tetsu Satow; Go Ikeda; Jun C Takahashi; Koji Iihara; Nobuyuki Sakai

  Neurologia medico-chirurgica 60 2 55 - 65 2020年02月 

  Endosaccular coiling is recognized as a feasible method for treating unruptured intracranial aneurysms (UIAs). We retrospectively reviewed cases of UIAs treated by coiling in the Japanese Registry of Neuroendovascular Therapy (JR-NET) 3, a nationwide survey of NET between 2010 and 2014, the beginning period of intracranial stents in Japan. Data were extracted for 6844 UIAs (6619 procedures) from 40,169 registered records of all NETs in the JR-NET 3 databases. The features of the aneurysms and procedures, immediate radiographic findings, procedure-related complications, and clinical outcomes at 30 days after the procedures were assessed. Of 6844 UIAs, 81.8% were located in the anterior circulation. The mean patient age was 61.3 years (72.4% females). Compared with the preceding JR-NET 1 and 2, there were significant increases (P <0.05) in the rates of the following in JR-NET 3: wide-necked and small UIAs measuring <10 mm (from 56.4% to 58.8%), adjunctive techniques (54.8% to 71.8%), and stent usage (1.1% to 22.1%). Both pre- (85.6% to 96.7%) and post-procedural (84.0% to 94.6%) antiplatelet therapy were more frequently administered in JR-NET 3. Although procedure-related complication rates did not differ between the two groups, ischemic complication rates increased from 4.6% to 5.9%, leading to an increase in the 30-day morbidity (modified Rankin Scale >2) from 2.1% to 2.8%. In conclusion, introduction of neck-bridge stent was associated with an increase in cases of wide-necked aneurysms. However, the ischemic complication rate increased despite the greater use of periprocedural antiplatelet therapy.
• The Current Status of Endovascular Treatment for Extracranial Steno-occlusive Diseases in Japan: Analysis Using the Japanese Registry of Neuroendovascular Therapy 3 (JR-NET3).

  Yukihiro Yamao; Akira Ishii; Tetsu Satow; Koji Iihara; Nobuyuki Sakai

  Neurologia medico-chirurgica 60 1 1 - 9 2020年01月 

  Endovascular treatment of extracranial steno-occlusive lesions is an alternative to direct surgery. There is no consensus regarding the natural course and standard treatment of these lesions. The aim of this study was to identify the current status of endovascular treatment for extracranial steno-occlusive lesions. A total of 1154 procedures for extracranial steno-occlusive lesions, except for internal carotid artery stenosis, were collected from the Japanese Registry of Neuroendovascular Therapy 3 (JR-NET3). Atherosclerotic lesions were most frequent (1021 patients, 88.5%). Endovascular treatment was performed for 456 (39.5%) patients with subclavian artery, 349 (30.2%) with extracranial vertebral artery, 172 (14.9%) with the origin of common carotid artery, and 38 (3.3%) with innominate artery stenosis; the overall technical success rate was 98.0%. Percutaneous transluminal angioplasty was performed in 307 patients (26.6%) and stenting in 838 (72.6%). An embolic protection device (EPD) was used in 571 patients (49.5%), and procedure under general anesthesia was performed in 168 (14.6%). Preoperative antiplatelet therapy was administered in 1091 procedures (94.5%). A good outcome was obtained for 962 patients (83.4%). Complications were observed in 89 patients (7.7%). The procedure under general anesthesia was statistically significant factors (P <0.01), and also after multivariable adjustment (odds ratio 2.29; 95% confidence interval 1.25-4.17; P <0.01). Comparisons between JR-NET3 and previous cohorts (JR-NET1&2), the utilization of EPD and complications increased significantly, and the type of antiplatelet therapy changed markedly. Based on the results of this study, endovascular treatment for extracranial steno-occlusive lesions is relatively safe. Further prospective studies are necessary to validate the beneficial effects.
• Nationwide questionnaire survey on neuroimaging strategy for acute ischemic stroke in Japan

  Takashi Okada; Manabu Inoue; Hiroshi Yamagami; Kanta Tanaka; Masayuki Shiozawa; Kazutaka Sonoda; Hajime Ikenouchi; Tetsuya Fukuda; Tetsu Satow; Masafumi Ihara; Kohsuke Kudo; Ryo Itabashi; Kazunori Toyoda; Masatoshi Koga

  Japanese Journal of Stroke 42 6 502 - 508 2020年 [査読有り]
  
• Acute cerebrovascular imaging for stroke management: a literature review

  Masatoshi Koga; Manabu Inoue; Kazutaka Sonoda; Kanta Tanaka; Masayuki Shiozawa; Takashi Okada; Hajime Ikenouchi; Tetsuya Fukuda; Tetsu Satow; Masafumi Ihara; Ryo Itabashi; Kohsuke Kudo; Hiroshi Yamagami; Kazunori Toyoda

  Japanese Journal of Stroke 42 6 495 - 501 2020年
• Endovascular Treatment of Cavernous Sinus Dural Arteriovenous Fistulae: Review of the Literature and Current Status.

  Tetsu Satow

  Journal of neuroendovascular therapy 14 12 572 - 582 2020年 

  Cavernous sinus dural arteriovenous fistulae (CSdAVFs) are characterized by the shunts between dural arteries and dural veins surrounding the cavernous sinus (CS), causing ocular symptoms in addition to intracranial hemorrhage and infarction. As surgical access is difficult, endovascular treatment (EVT) has been considered and performed as the first-line therapy for decades. Although there have been recent advances in techniques and devices, transvenous embolization (TVE) with platinum coils remains the most common procedure. There are multiple access routes to the CS, such as the inferior petrosal sinus, superior ophthalmic vein (SOV), and intercavernous sinus from the contralateral CS. To extirpate the shunt, packing the entire sinus with coils is adopted, occasionally resulting in persistent cranial nerve palsy (CNP) due to compression of the coil mass. To avoid this complication, selective shunt occlusion (SSO), in which the coils are placed in the shunted pouch (SP) defined by the small restricted space where the arterial flow converges, is an effective and safe method. Transarterial embolization (TAE) is another option and use of liquid embolic materials, such as Onyx may be promising; however, the potential risk of ischemic nerve injury due to undesirable ante/retrograde influx of the liquid materials is of concern. In conclusion, EVT, especially TVE, is a safe and effective method for managing CSdAVFs. Understanding the angioanatomy consisting of the feeding artery, shunt point, and the drainage route, including the latent vessels, is essential for a good outcome.
• A Case of Internal Carotid Artery Dissection with Ischemic Onset, Followed by Subarachnoid Hemorrhage during Diagnostic Angiography.

  Takuma Maeda; Tetsu Satow; Eika Hamano; Naoki Hashimura; Junpei Koge; Kanta Tanaka; Takeshi Yoshimoto; Manabu Inoue; Masatoshi Koga; Masaki Nishimura; Jun C Takahashi

  Journal of neuroendovascular therapy 14 10 420 - 427 2020年 

  OBJECTIVE: Internal carotid artery (ICA) dissection is known to cause binary types of stroke, cerebral infarction, and subarachnoid hemorrhage (SAH). However, it is rare that these two pathologies take place in a clinical scenario. We report a case of ICA dissection with ischemic onset, which was followed by SAH on the same day during diagnostic angiography. CASE PRESENTATION: A 60-year-old woman with chronic hypertension rapidly developed right hemiplegia. She had been suffering from slight headache and abnormal sensation in the right limbs 1 week before the ictus. MRI demonstrated small acute infarctions in the left middle cerebral artery (MCA) territory. The left ICA was not visualized on MRA. Diffusion-perfusion mismatch was indicated by the automated image postprocessing system. Endovascular recanalization was planned to prevent the progression of cerebral infarction. After advancing a 5MAX ACE, initial left ICA angiography was performed, resulting in extravasation of contrast medium from the C2 segment of the left ICA. 3D rotational angiography revealed left ICA dissection of the C2 segment. To secure hemostasis, the patient underwent internal trapping at the C1 and C2 segments of the left ICA. Collateral flow to the left MCA via an anterior communicating artery was observed. On day 28, the patient was transferred to a rehabilitation hospital with right hemiplegia and motor aphasia. CONCLUSION: In cases of tandem lesions with preceding neurological symptoms, ICA dissection should be considered as one of the causes. Careful injection of contrast medium may be necessary if ICA dissection is strongly suspected.
• Clinical Characteristics and Endovascular Treatment for Spinal Dural Arteriovenous Fistula in Japan: Japanese Registry of Neuroendovascular Therapy 2 and 3.

  Wataro Tsuruta; Yuji Matsumaru; Koji Iihara; Tetsu Satow; Nobuyuki Sakai; Masahiro Katsumata; Hisayuki Hosoo; Masayuki Sato; Yoshiro Ito; Aiki Marushima; Mikito Hayakawa; Eiichi Ishikawa; Akira Matsumura

  Neurologia medico-chirurgica 59 12 492 - 497 2019年12月 

  A subgroup analysis of spinal vascular lesions registered in the Japanese Registry of Neuroendovascular Therapy 2 (JR-NET2) and JR-NET3 was performed. About 172 analyzable cases of spinal dural arteriovenous fistula (SDAVF) were assessed, including the characteristics, treatment strategy, and treatment outcome. SDAVF was more common in middle-aged and older males. The most commonly affected area was the thoracolumbosacral region (83.7%), and most cases had a non-hemorrhagic onset (89.0%). Complete obliteration was achieved in 54.7%. Treatment-related complications occurred in three patients (7.0%). Post-treatment neurological improvement was achieved in 48.3%. The primary endpoint [modified Rankin Scale (mRS) score of 0-2 on postoperative day 30] was achieved in 60.5% of the cases. As a new discovery, the incidence of cervical SDAVF increased from 1.8% in JR-NET2 to 19.7% in JR-NET3. Compared with non-cervical SDAVF, cervical SDAVF was characterized by a higher proportion of hemorrhagic onset (P <0.01), incomplete obliteration of the shunt (P <0.01), and embolization-related complications (P = 0.01). Overall, a mRS of 0-2 on postoperative day 30 was correlated with a pre-treatment mRS of 0-2 (P <0.01) in a univariate analysis. Complete obliteration of the shunt was the only predictor of postoperative neurological improvement (P = 0.001) in a multivariate analysis. Endovascular treatment for SDAVF has been safely administered in Japan. The incidence of cervical SDAVF, which has more aggressive features, appears to be increasing. Early diagnosis and complete obliteration of the shunt are important for improving the treatment outcomes of patients with SDAVF.
• Safety and Feasibility of Neuroendovascular Therapy for Elderly Patients: Analysis of Japanese Registry of Neuroendovascular Therapy 3.

  Koichi Arimura; Koji Iihara; Tetsu Satow; Ataru Nishimura; So Tokunaga; Nobuyuki Sakai

  Neurologia medico-chirurgica 59 8 305 - 312 2019年08月 

  Japan has a rapidly aging population and the application of neuroendovascular therapy (NET) for cerebrovascular diseases among elderly patients has increased, but feasibility and safety of NET for elderly patients are still debated. Therefore, this study aimed to elucidate feasibility and safety of NET by analyzing the Japanese nationwide database, the Japanese Registry of Neuroendovascular Therapy 3 (JR-NET 3). In total, 35,972 patients in the JR-NET 3 were analyzed retrospectively. "Elderly patients" were defined as those aged ≥75 years. Approximately one-quarter of patients who received NET were elderly patients. The proportion of patients with modified Rankin Scale (mRS) 0-2 before treatment and 30 days after NET was significantly low across all diseases in the elderly patients. Technical success rates were generally high across all procedures, but complication rate was significantly higher among elderly patients; ischemic complications were significantly higher with NET for unruptured aneurysms (UA) and carotid artery stenosis (CAS). Multivariate analysis revealed that mRS 0-2 before treatment [odds ratio (OR): 0.56, 95% confidence interval (CI): 0.34-0.94, P = 0.03], middle cerebral artery aneurysm (OR: 0.33, 95% CI: 0.12-0.92, P = 0.04), and complete obliteration (OR: 0.66, 95% CI: 0.44-0.97, P = 0.03) were associated with ischemic complications with NET for UA. Moreover, mRS 0-2 before treatment (OR: 0.55, 95% CI: 0.36-0.86, P < 0.01), high intensity with time-of-flight magnetic resonance angiography (OR: 1.55, 95% CI: 1.03-2.32, P = 0.04), open-cell stent (OR: 2.20, 95% CI: 1.50-3.22, P <0.01) were associated with ischemic complications with NET for CAS. Taken together, our findings indicate that cautious and precise selection of patients suitable for NET is necessary.
• Case of Iatrogenic Vertebro-Vertebral Arteriovenous Fistula Treated by Combination of Double-Catheter and Balloon Anchoring Techniques.

  Isao Ono; Tetsu Satow; Yoshiro Ito; Eika Hamano; Hirofumi Matsubara; Hiroharu Kataoka; Jun C Takahashi

  World neurosurgery 128 98 - 101 2019年08月 

  BACKGROUND: A case of high-flow cervical vertebro-vertebral arteriovenous fistula (VVAVF), which was occluded with detachable coils by the transarterial/transvenous double-catheter technique and balloon anchoring technique, is reported. CASE DESCRIPTION: A 32-year-old male who had a history of dilated cardiomyopathy, heart failure, and arrhythmia under anticoagulation presented with a neck bruit after a right internal jugular vein puncture. A high-flow VVAVF between the right vertebral artery (VA) and vertebral vein (VV) was revealed by ultrasonography and angiography. To extirpate the shunt while preserving the right VA without using a stent to avoid antiplatelet therapy, the double-catheter technique was used to occlude the vein and shunt tightly, 1 catheter from the venous side and the other from the VA to the VV through the shunt. Finally, stabilization of the coil cage in the dilating VV was secured by placing a balloon distally as an anchor and successfully occluding the shunt with small amounts of coils only on the venous side. The shunt and cervical bruit disappeared immediately after the treatment, and no recurrence was observed. CONCLUSIONS: The double-catheter technique and balloon anchoring technique used in this case seem effective for transvenous embolization of VVAVF when preservation of the VA is desired.
• Spontaneous Persistent Primitive Trigeminal Artery-Cavernous Sinus Fistula Successfully Treated by Multipronged Coil Embolization: Case Report and Literature Review.

  Taichi Ishiguro; Tetsu Satow; Akihiro Okada; Eika Hamano; Go Ikeda; Hidekazu Chikuie; Takao Koiso; Naoki Hashimura; Masaki Nishimura; Jun C Takahashi

  World neurosurgery 128 122 - 126 2019年08月 

  BACKGROUND: A spontaneous persistent primitive trigeminal artery-cavernous sinus fistula (PCF) is extremely rare. Until recently, endovascular treatment for PCF involving transarterial and/or transvenous coil embolization of the cavernous sinus (with/without the persistent trigeminal artery) was commonly performed. However, it may result in remaining shunt flow or exacerbation of cranial nerve palsy. CASE DESCRIPTION: A 51-year-old woman presented with headache and left abducens palsy. Digital subtraction angiography demonstrated a direct fistula between the cavernous segment of the persistent primitive trigeminal artery (PPTA) and posterosuperior compartment of the left cavernous sinus (CS). Three microcatheters were guided into the fistula as follows: 1) through the PPTA to the CS from the left internal carotid artery, 2) through the PPTA to the CS from the basilar artery, and 3) through the CS to the PPTA from the internal jugular vein. Using the double-catheter technique in a multidirectional fashion, shunt occlusion was achieved with a small number of coils. No signs of recurrence were observed during the follow-up period. CONCLUSIONS: The multipronged approach is safe and effective for embolization of a small tortuous artery and shunt segment to avoid incomplete shunt occlusion.
• A comparison of the prevalence and risk factors of complications in intracranial tumor embolization between the Japanese Registry of NeuroEndovascular Therapy 2 (JR-NET2) and JR-NET3.

  Tomohito Hishikawa; Kenji Sugiu; Satoshi Murai; Yu Takahashi; Naoya Kidani; Shingo Nishihiro; Masafumi Hiramatsu; Isao Date; Tetsu Satow; Koji Iihara; Nobuyuki Sakai

  Acta neurochirurgica 161 8 1675 - 1682 2019年08月 

  BACKGROUND: The Japanese Registry of NeuroEndovascular Therapy 2 (JR-NET2) and 3 (JR-NET3) were nationwide surveys that evaluated clinical outcomes after neuroendovascular therapy in Japan. The aim of this study was to compare the prevalence and risk factors of complications of intracranial tumor embolization between JR-NET2 and JR-NET3. METHODS: A total of 1018 and 1545 consecutive patients with intracranial tumors treated with embolization were enrolled in JR-NET2 and JR-NET3, respectively. The prevalence of complications in intracranial tumor embolization and related risk factors were compared between JR-NET2 and JR-NET3. RESULTS: The prevalence of complications in JR-NET3 (3.69%) was significantly higher than that in JR-NET2 (1.48%) (p = 0.002). The multivariate analysis in JR-NET2 showed that embolization for tumors other than meningioma was the only significant risk factor for complication (odds ratio [OR], 3.88; 95% confidence interval [CI], 1.13-12.10; p = 0.032), and that in JR-NET3 revealed that embolization for feeders other than external carotid artery (ECA) (OR, 3.56; 95% CI, 2.03-6.25; p < 0.001) and use of liquid materials (OR, 2.65; 95% CI, 1.50-4.68; p < 0.001) were significant risks for complications. The frequency of embolization for feeders other than ECA in JR-NET3 (15.3%) was significantly higher than that in JR-NET2 (9.2%) (p < 0.001). Also, there was a significant difference in the frequency of use of liquid materials between JR-NET2 (21.2%) and JR-NET3 (41.2%) (p < 0.001). CONCLUSIONS: Embolization for feeders other than ECA and use of liquid materials could increase the complication rate in intracranial tumor embolization.
• Detrimental Effect of Chronic Hypertension on Leptomeningeal Collateral Flow in Acute Ischemic Stroke.

  Kyohei Fujita; Kanta Tanaka; Hiroshi Yamagami; Toshihiro Ide; Hiroyuki Ishiyama; Kazutaka Sonoda; Tetsu Satow; Jun C Takahashi; Masafumi Ihara; Masatoshi Koga; Takanori Yokota; Kazunori Toyoda

  Stroke 50 7 1751 - 1757 2019年07月 

  Background and Purpose- We aimed to evaluate the effect of chronic hypertension on acute leptomeningeal collateral flow in patients with large-vessel ischemic stroke using digital subtraction angiography, which is the gold standard for the assessment of collateral circulation. Methods- Of the consecutive ischemic stroke patients from October 2011 to December 2017 seen in our institution, patients with acute occlusion of the M1 segment of the middle cerebral artery confirmed on initial digital subtraction angiography were enrolled. Chronic hypertension was defined as its documentation before the index stroke or as the administration of antihypertensive medications before onset. Angiographic leptomeningeal collateral flow was evaluated according to the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology Collateral Flow Grading System and dichotomized the findings into excellent (grade 3-4) or poor (grade 0-2) collateral status for analysis. Results- Of the 3759 consecutive ischemic stroke patients, 100 patients were analyzed. Thirty-nine patients (39%) had poor collateral status. Patients with poor collateral status were older, more frequently male, and had chronic hypertension more frequently, shorter time from onset to angiography, and higher admission systolic blood pressure than those with excellent collateral status. Multivariable logistic analysis with prespecified covariates showed a significantly positive association between chronic hypertension and poor collateral status (odds ratio, 2.80; 95% CI, 1.08-7.70; P=0.034). This association was independent of admission systolic blood pressure. The proportion of patients with poor collateral status increased in a stepwise manner in patients without chronic hypertension, hypertensive patients with premorbid antihypertensive medications, and hypertensive patients without antihypertensive medications ( P for trend <0.001). Conclusions- Our data suggest that chronic hypertension has a detrimental effect on acute leptomeningeal collateral flow in patients with cerebral large-vessel occlusion. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT02251665.
• Results of 1940 embolizations for dural arteriovenous fistulas: Japanese Registry of Neuroendovascular Therapy (JR-NET3).

  Masafumi Hiramatsu; Kenji Sugiu; Tomohito Hishikawa; Shingo Nishihiro; Naoya Kidani; Yu Takahashi; Satoshi Murai; Isao Date; Naoya Kuwayama; Tetsu Satow; Koji Iihara; Nobuyuki Sakai

  Journal of neurosurgery 1 - 8 2019年06月 

  OBJECTIVE: Embolization is the most common treatment for dural arteriovenous fistulas (dAVFs). A retrospective, multicenter observational study was conducted in Japan to clarify the nature, frequency, and risk factors for complications of dAVF embolization. METHODS: Patient data were derived from the Japanese Registry of Neuroendovascular Therapy 3 (JR-NET3). A total of 40,169 procedures were registered in JR-NET3, including 2121 procedures (5.28%) in which dAVFs were treated with embolization. After data extraction, the authors analyzed complication details and risk factors in 1940 procedures performed in 1458 patients with cranial dAVFs treated with successful or attempted embolization. RESULTS: Transarterial embolization (TAE) alone was performed in 858 cases (44%), and transvenous embolization (TVE) alone was performed in 910 cases (47%). Both TAE and TVE were performed in one session in 172 cases (9%). Complications occurred in 149 cases (7.7%). Thirty-day morbidity and mortality occurred in 55 cases (2.8%) and 16 cases (0.8%), respectively. Non-sinus-type locations, radical embolization as the strategy, procedure done at a hospital that performed dAVF embolization in fewer than 10 cases during the study period, and emergency procedures were independent risk factors for overall complications. CONCLUSIONS: Complication rates of dAVF embolization in Japan were acceptable. For better results, the risk factors identified in this study should be considered in treatment decisions.
• Evaluating the safety and technical effectiveness of a newly developed intravascular 'flow isolator' stent for the treatment of intracranial aneurysms: study protocol for a first-in-human single-arm multiple-site clinical trial in Japan.

  Haruko Yamamoto; Toshimitsu Hamasaki; Kaori Onda; Yasuhide Nakayama; Akira Ishii; Hidenori Oishi; Nobuyuki Sakai; Tetsu Satow

  BMJ open 9 5 e020966  2019年05月 

  INTRODUCTION: Wide-neck or large intracranial aneurysms are difficult to cure by conventional surgical or endovascular procedures. A flow diverter (FD) is an implantable, stent-like, fine-mesh medical device for the treatment of intracranial aneurysms. Although endovascular treatment with FDs is becoming a routine first-line option, a systematic review noted the heterogeneity and publication biases of the clinical studies for FDs. We have developed a new honeycomb microporous covered stent (NCVC-CS1) as a 'flow isolator' for the endovascular treatment of intracranial aneurysms. METHODS AND ANALYSIS: We planned the NCVC-CS1_UAN as a first-in-human study to evaluate the safety and technical effectiveness of the NCVC-CS1, a newly developed honeycomb microporous covered stent, for the treatment of intracranial aneurysms that are difficult to cure by conventional surgical or endovascular procedures. The study is a multicentre, open-label, uncontrolled, exploratory, medical device, investigator-initiated clinical study. The primary safety endpoint of this study is any stroke or death related to the procedure within 180 days, while for efficacy, the endpoint is complete obliteration of the target aneurysm and patency of the target vessel (less than 50% stenosis) confirmed by angiography at 180 days after the procedure. ETHICS AND DISSEMINATION: Full ethics approval of institutional review boards was obtained at all participating sites. A clinical trial notification as a new medical device was accepted by the Japanese regulatory agency before it started. The study should be followed by a pivotal study to obtain satisfactory data for an application for marketing approval. The main results of this study will be submitted for publication in a peer-reviewed journal. The planned subject number for this study is 12. TRIAL REGISTRATION NUMBER: NCT02907229.
• Real-world Experience of Carotid Artery Stenting in Japan: Analysis of 8458 Cases from the JR-NET3 Nationwide Retrospective Multi-center Registries.

  Ryo Tokuda; Shinichi Yoshimura; Kazutaka Uchida; Kiyofumi Yamada; Tetsu Satow; Koji Iihara; Nobuyuki Sakai

  Neurologia medico-chirurgica 59 4 117 - 125 2019年04月 

  We aimed to clarify the outcomes of carotid artery stenting (CAS) in the Japanese population. For this purpose, we reviewed data from the Japanese Registry of NeuroEndovascular Therapy 3 (JR-NET3), a retrospective, nation-wide, multi-center, observational study of neuroendovascular treatments in Japan. Of the 9207 patients who underwent CAS between January 2010 and December 2014, 8458 satisfied the inclusion criteria for our analysis. The outcome statistics of this JR-NET3 cohort were compared to those of JR-NET1 and 2 cohorts fitting the same inclusion criteria. Of the 8458 JR-NET3 patients analyzed, 8042 (95.1%) were treated by surgeons with board certification from the Japanese Society for NeuroEndovascular Therapy. Technical success was achieved in 8417 patients (99.5%), whereas 198 patients (2.3%) had clinically significant complications (CSCs). These findings mirrored those obtained for the JR-NET1 and 2 cohorts. On multivariate analysis, risk factors for CAS-associated CSC included symptomatic lesion [odds ratio (OR), 1.91; 95% confidence interval (CI), 1.23-3.00; P = 0.003] and hypoechoic lesion on carotid artery ultrasound (OR, 1.85; 95% CI, 1.21-2.84; P = 0.005), whereas use of closed-cell stents was a predictor of better outcome (OR, 0.53; 95% CI, 0.35-0.79; P = 0.002). The findings of JR-NET3 reflect good outcomes of CAS, but non-modifiable risk factors reflecting lesion characteristics remain of concern. Using closed-cell stents is advisable. Technological advances such as the introduction of new materials may help further improve CAS outcomes in Japanese patients.
• Japanese Surveillance of Neuroendovascular Therapy in JR-NET - Part II. Japanese Registry of NeuroEndovascular Treatment 3. Main Report.

  Nobuyuki Sakai; Kazutaka Uchida; Koji Iihara; Tetsu Satow; Masayuki Ezura; Akio Hyodo; Shigeru Miyachi; Susumu Miyamoto; Yoji Nagai; Kunihiro Nishimura; Kazunori Toyoda; Shinichi Yoshimura; Hirotoshi Imamura; Chiaki Sakai; Yuji Matsumaru

  Neurologia medico-chirurgica 59 3 106 - 115 2019年03月 

  This study, following Japanese Registry of NeuroEndovascular Treatment 1 and 2 (JR-NET 1 & 2), shows an annual trend of cases including adverse events and clinical outcomes at 30 days after NET. JR-NET3 was registered by 749 cumulative total number of physicians, certified by the Japanese Society of Neuroendovascular Therapy in 166 centers, between 2010 and 2014. Medical information about the patients was anonymized and retrospectively registered through a website. A total of 40,177 patients were recruited, 632 patients were excluded because data of preprocedural status were not available. So we analyzed 39,545 patients retrospectively. The proportion of octogenarians is increasing year-by-year and 14.7% in 2014 compared with 10.4% in 2010. Most frequent target disease is intracranial aneurysm. For the proportion of the treatment of intracranial aneurysm, 50.0% in 2010, but that has decreased to 44.8% in 2014. However, number of procedures were increased from 3150 in 2010 to 3419 in 2014. Although before the positive clinical evidence of mechanical thrombectomy for acute ischemic stroke (AIS) was established, the proportion of endovascular treatment for AIS increased 13.8% in 2014 compared with 6.3% in 2010. The number of patients requiring neuroendovascular treatment in Japan is increasing since 2010-2013, but that declined a little in 2014 caused by study operation suspended at the end of 2013. The outcomes of such therapy are clinically acceptable. Details of each type of treatment will be investigated in sub-analyses of the database.
• Vascular wall components in thrombi obtained by acute stroke thrombectomy: clinical significance and related factors.

  Naoko Funatsu; Mikito Hayakawa; Tetsuya Hashimoto; Hiroshi Yamagami; Tetsu Satow; Jun C Takahashi; Masatoshi Koga; Kazuyuki Nagatsuka; Hatsue Ishibashi-Ueda; Toru Iwama; Kazunori Toyoda

  Journal of neurointerventional surgery 11 3 232 - 236 2019年03月 

  BACKGROUND AND PURPOSE: Vascular wall components (VWCs) are sometimes identified as collagen fibers in specimens retrieved by thrombectomy from acute stroke patients. However, their clinical significance and associated factors remain unclear. The purpose of this study was to clarify the factors associated with VWCs in retrieved thrombi. METHODS: Consecutive acute stroke patients treated endovascularly using the Penumbra aspiration catheter or stent retrievers (SRs) at our institute from November 2013 to April 2016 were retrospectively reviewed, and the retrieved thrombi were evaluated histopathologically. VWCs were defined as banded collagen fibers with a distinct boundary observed at the rim or outside of the retrieved thrombi. Factors associated with the presence of VWCs were studied. RESULTS: A total of 150 specimens (76 specimens retrieved by the Penumbra, 74 by SRs) from 101 patients (47 women, age 74.9±11.1 years) were investigated. Applied thrombectomy devices were aspiration catheters in 42 patients, SRs in 21 patients, and both in 38 patients. VWCs were observed in 24 specimens (16%) from 22 patients. A low proportion of erythrocyte components (41.7±24.8% vs 55.0±26.3%, P=0.01), a high frequency of the devices reaching the M2/P2 (75% vs 50%, P=0.02), and a high number of device passages (P for trend=0.02) were associated with VWC positive thrombi. Successful recanalization (Treatment in Cerebral Ischemia ≥2b) tended to be less frequent in patients with VWC positive thrombi than in those without (73% vs 89%, P=0.06). CONCLUSIONS: The histopathology of occlusive thrombi, arterial sites where devices reached, and number of device passages, might affect the presence of VWCs in retrieved thrombi.
• Treatment Outcome of Intracranial Tumor Embolization in Japan: Japanese Registry of NeuroEndovascular Therapy 3 (JR-NET3).

  Kenji Sugiu; Tomohito Hishikawa; Satoshi Murai; Yu Takahashi; Naoya Kidani; Shingo Nishihiro; Masafumi Hiramatsu; Isao Date; Tetsu Satow; Koji Iihara; Nobuyuki Sakai

  Neurologia medico-chirurgica 59 2 41 - 47 2019年02月 

  Embolization for intracranial tumor is performed as a standard endovascular treatment. A retrospective, multicenter, observational study was conducted to clarify the nature, frequency, and risk factors of complications in intracranial tumor embolization. Patients were derived from the Japanese Registry of NeuroEndovascular Therapy (JR-NET3) using data taken from January 2010 through December 2014 in Japan. A total of 40,169 patients were enrolled in JR-NET3, of which, 1,545 patients (3.85%) with intracranial tumors underwent embolization. The primary end point was the proportion of patients with a modified Rankin scale (mRS) score of 0-2 (independency) at 30 days after embolization. The secondary end point was the occurrence of complications related to the procedures. The risk factors of the development of complications were analyzed. The proportion of patients with mRS scores ≤2 at 30 days after procedure was 89.5%. Complications occurred in 57 of the 1544 patients (3.7%). Multivariate analysis showed that target vessels other than external carotid artery (ECA) (OR, 3.56; 95% CI, 2.03-6.25; P <0.001) and use of liquid material (OR, 2.65; 95% CI, 1.50-4.68; P <0.001) were significantly associated with the development of complications. In JR-NET3, the primary end point was 89.5%, and the procedure-related complication rate was 3.7%. Embolization from other than ECA was significant risk factor of the complications. In addition, increasing usage of liquid embolic material worsened the risk of complications.
• Selective Shunt Occlusion of Direct Carotid-Cavernous Fistula with Vascular Ehlers-Danlos Syndrome by Multidevice Technique: A Case Report and Technical Note.

  Yoshiro Ito; Tetsu Satow; Hirofumi Matsubara; Hiroharu Kataoka; Jun C Takahashi

  World neurosurgery 122 123 - 128 2019年02月 

  BACKGROUND: Vascular Ehlers-Danlos syndrome (vEDS) is a vascular disease associated with a genetic collagen abnormality. It is characterized by vessel fragility, vessel rupture, and massive hemorrhage. Carotid-cavernous fistula (CCF) is the most frequent neurovascular complication of vEDS. However, CCF treatment using conventional diagnostic angiography and neuroendovascular therapy can result in a high rate of major complications. CASE DESCRIPTION: We report a case of a right CCF in a 48-year-old man with vEDS. The carotid artery and jugular vein were exposed by direct neck dissection. To avoid systemic vascular complications, multiple catheters were inserted into the shunt segment via the carotid artery and jugular vein. This transarterial and transvenous multidevice technique enabled compact placement of coils in the shunt segment. The CCF was eliminated via selective shunt occlusion. Postoperative magnetic resonance imaging revealed occlusion of the right CCF. CONCLUSIONS: Selective shunt occlusion via a transarterial and transvenous multidevice technique is a useful and safe approach for treating vEDS-associated CCF.
• Parent Artery Occlusion for Unruptured Cerebral Aneurysms: Results of the Japanese Registry of Neuroendovascular Therapy 3.

  Hidehisa Nishi; Akira Ishii; Tetsu Satow; Koji Iihara; Nobuyuki Sakai

  Neurologia medico-chirurgica 59 1 1 - 9 2019年01月 

  Although the current standard treatment for unruptured aneurysms comprises surgical clipping or endovascular coiling, these techniques are not suitable for some cases, such as large, giant, and fusiform aneurysms. Endovascular parent artery occlusion (PAO), which includes internal trapping and proximal occlusion, is a well-established alternative treatment for such cases. Here, we retrospectively reviewed PAO cases from the Japanese Registry of Neuroendovascular Therapy 3, a nation-wide survey of all neuroendovascular therapy cases between 2010 and 2014. This dataset included 274 procedures with a mean patient age of 57.1 years and 55.4% female patients. For the treatment strategy, internal trapping was selected in 213 aneurysm cases (77.7%) and proximal occlusion in 61 aneurysm cases (22.2%). Most of the procedures were successfully completed (272/274: 99.2%). Immediately after treatment, angiographical complete occlusion was achieved in 248 cases (90.5%). Although the feasibility of this technique was excellent, there were 60 periprocedural complications (21.8%), including 48 ischemic complications (17.5%), seven hemorrhagic complications (2.5%). Overall, morbidity and mortality at 30 days postoperative were 5.8% and 0.7%, respectively. Among the pretreatment variables, a patient age of 70 and older was associated with ischemic complications [odds ratio (OR); 2.34, 95% confidence interval (CI); 1.02-5.25; P = 0.04] and a small aneurysm size (<5 mm) was associated with hemorrhagic complications (OR; 9.85, 95% CI; 1.07-221.0; P = 0.04) by multivariate analysis. In conclusion, PAO for unruptured cerebral aneurysms is feasible, but is associated with a complication rate of approximately 20%. Various alternative treatment options should be carefully considered with deconstructive strategies.
• Endovascular Treatment for Vasospasm after Aneurysmal Subarachnoid Hemorrhage Based on Data of JR-NET3.

  Hirotoshi Imamura; Nobuyuki Sakai; Tetsu Satow; Koji Iihara

  Neurologia medico-chirurgica 58 12 495 - 502 2018年12月 

  Endovascular treatments for vasospasm after subarachnoid hemorrhage are typically performed for patients who are refractory to recommended medical therapies. We analyzed the current status of endovascular treatments based on the data of Japanese Registry of Neuroendovascular Therapy (JR-NET)3, and evaluated factors related to improvement of imaging findings and neurological condition, and to mechanical hemorrhage complications. We collected data of 1211 treatments performed from 2010 to 2014. Target vessels for treatments were anterior circulation (n = 1079), posterior circulation (n = 91), and both (n = 32); the distribution of vasospasm was the proximal vessel (n = 754) to the Circle of Willis, distal vessel (n = 329), and both (n = 119). Of the treatments, 948 cases (78.3%) were intra-arterial administration of vasodilators and 259 (21.4%) were percutaneous transluminal angioplasty (PTA); 879 cases were the first intervention. The treatment time from onset was within 3 h in 378 (31.2%) cases, between 3 and 6 h in 349 (28.8%) cases, and over 6 h in 245 (20.2%) cases. The statistically significant factors associated with improvement on imaging findings was the first treatment, and treatment within 3 h from onset compared with that after 6 h. Additionally, the first and early treatments after the symptoms were associated with significantly improved neurological condition. All complications of mechanical hemorrhage occurred along with PTA. The findings show that endovascular treatment for vasospasm was effective, especially for cases who suffered from symptomatic vasospasm with a short interval after onset.
• Long-term outcomes of coil embolization of unruptured intracranial aneurysms.

  Masaomi Koyanagi; Akira Ishii; Hirotoshi Imamura; Tetsu Satow; Kazumichi Yoshida; Hitoshi Hasegawa; Takayuki Kikuchi; Yohei Takenobu; Mitsushige Ando; Jun C Takahashi; Ichiro Nakahara; Nobuyuki Sakai; Susumu Miyamoto

  Journal of neurosurgery 129 6 1492 - 1498 2018年12月 

  OBJECTIVE Long-term follow-up results of the treatment of unruptured intracranial aneurysms (UIAs) by means of coil embolization remain unclear. The aim of this study was to analyze the frequency of rupture, retreatment, stroke, and death in patients with coiled UIAs who were followed for up to 20 years at multiple stroke centers. METHODS The authors retrospectively analyzed data from cases in which patients underwent coil embolization between 1995 and 2004 at 4 stroke centers. In collecting the late (≥ 1 year) follow-up data, postal questionnaires were used to assess whether patients had experienced rupture or retreatment of a coiled aneurysm or any stroke or had died. RESULTS Overall, 184 patients with 188 UIAs were included. The median follow-up period was 12 years (interquartile range 11–13 years, maximum 20 years). A total of 152 UIAs (81%) were followed for more than 10 years. The incidence of rupture was 2 in 2122 aneurysm-years (annual rupture rate 0.09%). Nine of the 188 patients with coiled UIAs (4.8%) underwent additional treatment. In 5 of these 9 cases, the first retreatment was performed more than 5 years after the initial treatment. Large aneurysms were significantly more likely to require retreatment. Nine strokes occurred over the 2122 aneurysm-years. Seventeen patients died in this cohort. CONCLUSIONS This study demonstrates a low risk of rupture of coiled UIAs with long-term follow-up periods of up to 20 years. This suggests that coiling of UIAs could prevent rupture for a long period of time. However, large aneurysms might need to be followed for a longer time.
• Neurosurgical Management and Outcomes of Cerebrovascular Disease in Pediatric Patients with Heart Disease.

  Daisuke Maruyama; Hiroharu Kataoka; Tetsu Satow; Hisae Mori; Yoshiro Ito; Eika Hamano; Shunichi Tanaka; Taichi Ishiguro; Hidekazu Chikuie; Jun C Takahashi

  Neurologia medico-chirurgica 58 8 334 - 340 2018年08月 

  Antithrombotic treatment has substantial risks, even in pediatric patients. We retrospectively evaluated the management and outcomes of consecutive pediatric patients who underwent neurosurgical treatment for cerebrovascular disease with cardiovascular disease between 1998 and 2017. Patients were divided into patients with comorbid cardiovascular disease (group I); and patients with cardiovascular disease as a primary disease of intracranial complication, without (group IIa) or with (group IIb) extracorporeal circulations. Postoperative resumption of antithrombotic agents was generally initiated within 48 h. Our study included 26 patients; five were categorized as group I, 15 as group IIa, and six as group IIb. All intracranial diseases in groups IIa and IIb were exclusively hemorrhagic. Preoperative anticoagulation therapy was used in one patient (20%) in group I, 13 patients (86.7%) in group IIa, and six patients (100%) in group IIb. Postoperative intracranial hemorrhagic events were observed in one patient (20%) in group I, three patients (20%) in group IIa, and four patients (66.7%) in group IIb. Re-operations were conducted in two (13.3%) and three patients (50%) in groups IIa and IIb, respectively. Death occurred in five (33.3%) and four patients (66.7%) in groups IIa and IIb, respectively. The remaining two patients in group IIb returned to candidate status for implantation. Emergent surgery for patients with intracranial hemorrhage associated with cardiovascular disease has a high risk of postoperative hemorrhagic events and high rate of re-operations with poor vital outcomes, especially in patients with extracorporeal circulations. We should consider maximum neurosurgical treatment achievable with optimal management of antithrombotic treatment.
• Response to "Letter on 'Management of pregnancy complicated with intracranial arteriovenous malformation'".

  Shinji Katsuragi; Jun Yoshimatsu; Hiroaki Tanaka; Kayo Tanaka; Masafumi Nii; Takekazu Miyoshi; Reiko Neki; Kazunori Toyoda; Kazuyuki Nagatsuka; Jun C Takahashi; Kenji Fukuda; Eika Hamano; Tetsu Satow; Susumu Miyamoto; Koji Iihara; Tomoaki Ikeda

  The journal of obstetrics and gynaecology research 44 7 1335 - 1335 2018年07月
• Efficacy and Safety of REVIVE SE Thrombectomy Device for Acute Ischemic Stroke: River JAPAN (Reperfuse Ischemic Vessels with Endovascular Recanalization Device in Japan).

  Nobuyuki Sakai; Shinzo Ota; Yasushi Matsumoto; Rei Kondo; Tetsu Satow; Michiya Kubo; Tomoyuki Tsumoto; Yukiko Enomoto; Taketo Kataoka; Hirotoshi Imamura; Kenichi Todo; Mikito Hayakawa; Hiroshi Yamagami; Kazunori Toyoda; Yasushi Ito; Kenji Sugiu; Yuji Matsumaru; Shinichi Yoshimura

  Neurologia medico-chirurgica 58 4 164 - 172 2018年04月 

  REVIVE SE (REVIVE) is a closed-ended, self-expanding stent retriever used in the RIVER JAPAN study. We present our early experience with REVIVE for revascularization of acute ischemic stroke (AIS) in patients who have failed or are ineligible for intravenous recombinant tissue plasminogen activator treatment. This prospective, single-arm, non-randomized, multicenter registry study followed up patients undergoing mechanical thrombectomy with REVIVE for 90 days. The primary endpoint was a post-procedure Thrombolysis in Cerebral Infarction (TICI) score ≥2a. Secondary endpoints were clot migration/embolization; recanalization without symptomatic intracranial hemorrhage (ICH) at 24 h; symptomatic ICH; good neurological outcome (modified Rankin Scale score ≤2 National Institute of Health Stroke Scale (NIHSS) score decrease ≥10) at day 90; device- or procedure-related serious adverse events (SAEs) and mortality at day 90. To confirm non-inferiority of REVIVE, results were compared with historical data of the Merci Retriever. About 49 patients were enrolled (median age 73 years; males 46.9%; middle cerebral artery (MCA) occlusion 83.7%; median NIHSS score 17). A post-procedure TICI score ≥2a was observed in 73.5% (36/49, 95% confidence interval [CI] 58.9-85.1) of patients. No post-procedural clot migration/embolization events occurred. Successful recanalization without symptomatic ICH was observed in 62.5% (30/48, 95% CI 47.4-76.0). The good neurological outcome was achieved in 66.7% (32/48) patients. Symptomatic ICH and device- or procedure-related SAEs were reported in 6.3% and 12.2% of patients, respectively. Two deaths were reported. REVIVE demonstrated equivalent efficacy and safety as the Merci Retriever. Results suggest that REVIVE is effective and safe in recanalizing occluded intracranial arteries in AIS.
• Management of pregnancy complicated with intracranial arteriovenous malformation.

  Shinji Katsuragi; Jun Yoshimatsu; Hiroaki Tanaka; Kayo Tanaka; Masafumi Nii; Takekazu Miyoshi; Reiko Neki; Kazunori Toyoda; Kazuyuki Nagatsuka; Jun C Takahashi; Kenji Fukuda; Eika Hamano; Tetsu Satow; Susumu Miyamoto; Koji Iihara; Tomoaki Ikeda

  The journal of obstetrics and gynaecology research 44 4 673 - 680 2018年04月 

  AIM: To clarify the perinatal outcomes in pregnancy complicated with intracranial arteriovenous malformation (i-AVM). METHODS: A retrospective study was performed in 36 pregnancies complicated by i-AVM from 1981 to 2013 at one institution. RESULTS: In total, 6 women miscarried, and 30 had live births. The median (range) gestational age at delivery was 38 (24-40) weeks; 11 cases experienced initial i-AVM rupture during pregnancy (first, second and third trimester: 18%, 64% and 18%, respectively). At onset, 4 cases had a Glasgow Coma Scale ≤10, 10 cases needed emergency maternal transport, 4 underwent neurosurgery with the fetus in utero and 4 had termination of pregnancy in the second trimester for emergent treatment for i-AVM. Two cases delivered vaginally. Another 25 cases had already been diagnosed as i-AVM at conception. Of these, as an indication for epidural birth, 18 cases had either residual lesion of i-AVM or neurological symptoms, although 18 cases had received treatments of i-AVM before conception. Without rupture of i-AVM and worsening of symptoms, 15 cases succeeded in epidural birth. One case was delivered by cesarean section for residual i-AVM with indication of treatment. Another case who had refused treatment of i-AVM experienced rupture of i-AVM 1 year after delivery. CONCLUSION: Most of the cases with residual i-AVM lesion and neurological symptoms could deliver vaginally without worsening of symptoms. However, pregnancy with i-AVM can be complicated by rupture of i-AVM. In cases with a residual lesion with indication of treatment and rupture of i-AVM during pregnancy, meticulous care is required during pregnancy and after delivery.
• Natural history of unruptured intracranial aneurysms

  Jun C. Takahashi; Hiroharu Kataoka; Tetsu Satow; Hisae Mori

  Japanese Journal of Neurosurgery 27 3 184 - 191 2018年 [査読有り]
   

  Since 2003, five prospective studies on unruptured intracranial aneurysms have demonstrated their natural course (i.e. annual rupture rates) in detail. Recently, in addition, several meta-analyses, pooled analyses, risk scoring studies have been reported. Because there are many quotations of clinical data between these kinds of analyses, one must understand precisely where the pooled data come from. The risk factors for aneurysmal rupture proposed in the five prospective studies differ greatly from each other, and one must also understand these differences as well. UCAS, which is the prospective multicenter study across Japan published in 2012, has marked the milestone in the field of intracranial aneurysm research especially in the Japanese cohort. To make reasonable judgements in daily clinical activities, physicians should read the UCAS manuscript and its supplementary appendix carefully and understand the true natural course of unruptured intracranial aneurysms in Japan.
• Multimodal Interventional Treatment and Outcomes for Unruptured Arteriovenous Malformations.

  Daisuke Maruyama; Tetsu Satow; Hiroharu Kataoka; Hisae Mori; Eika Hamano; Yoji Orita; Seiichiro Eguchi; Jun C Takahashi

  Acta neurochirurgica. Supplement 129 115 - 120 2018年 

  BACKGROUND: This study aimed to evaluate the selection and outcomes of multimodal interventional treatment for unruptured brain arteriovenous malformations (uAVMs) in ARUBA-eligible patients in a single institution. METHODS: We retrospectively reviewed the data of 94 patients with uAVMs treated between 2002 and 2014. They were divided into an intervention group and a conservative group. The primary outcome was defined as the composite of death or symptomatic stroke. Functional outcome was assessed using the modified Rankin Scale (mRS). RESULTS: The intervention and conservative groups included 75 and 19 patients, respectively, with mean follow-up periods of 59.2 ± 41.6 and 72.8 ± 39.2 months (P = 0.20), among whom the primary outcome occurred in 9 (12.3%) and 3 (17.6%) patients, respectively (P = 0.91). The proportion of patients with an mRS score ≥ 2 at last follow-up was not significantly different between the two groups (6.9% vs. 11.7%). In the intervention group, the incidence of death or stroke was lower and functional outcomes were better among patients with grade I/II AVMs than among patients with grade III AVMs. CONCLUSION: For patients with uAVMs, interventional treatment is not inferior to medical treatment alone, and careful selection should be made for patients with grade III AVMs.
• Effectiveness of Preradiosurgical Embolization with NBCA for Arteriovenous Malformations - Retrospective Outcome Analysis in a Japanese Registry of 73 Patients (J-REAL study).

  Shigeru Miyachi; Takashi Izumi; Tetsu Satow; Kittipong Srivatanakul; Yasushi Matsumoto; Tomoaki Terada; Yuji Matsumaru; Hiro Kiyosue

  Neurointervention 12 2 100 - 109 2017年09月 

  PURPOSE: Recent reports have posed doubts about the effect of preradiosurgical embolization in brain arteriovenous malformation (AVM) because it makes the planning of stereotactic radiosurgery (SRS) difficult and has the risk of recanalization out of the target. We investigated whether the performance and quality of embolization may influence the success of SRS based on a retrospective case cohort study. MATERIALS AND METHODS: Seventy-three patients who underwent embolization followed by SRS between 2003 and 2012 in eight institutes with neurointerventionists were considered. They were divided into the following two groups at 3 years of follow up after the final SRS: "successful occlusion group" (S group), with radiologically complete occlusion of AVM; and "non-successful occlusion group" (N group) with persistent remnant nidus or abnormal vascular networks. Patient background, AVM profile, embolization performance grade and complications were compared in each group. The quality of embolization was evaluated with the new grading system: embolization performance grade (E grade), specializing the achievement of nidus embolization. E grade A was defined as sufficient nidus embolization with more than half of the total number of feeders achieving nidus penetration. E grade B was defined as less than half achievement of nidus embolization, and E grade C was defines as failure to perform nidus embolization. RESULTS: Forty-three patients were included in the S group, and 29 patients were included in the N group. The size and Spetzler-Martin grade of AVM and the rate of diffuse type was higher in the N group without statistical significance. The embolization performance level according to E grade indicated a significantly higher rate of successful embolization with more than 50% of nidus penetration in the S group (P<0.001). This difference was also confirmed in the subanalysis for limited cases, excluding smaller AVMs with complete occlusion with SRS alone (P=0.001). CONCLUSION: The cause of the unsuccessful result of post-embolization SRS might be the large, diffuse angioarchitecture, but proper embolization with a high rate of nidus penetration to avoid recanalization is more important. Effective embolization is essential to contribute to and promote the effect of radiosurgery.
• Clinical implications of the cortical hyperintensity belt sign in fluid-attenuated inversion recovery images after bypass surgery for moyamoya disease.

  Eika Hamano; Hiroharu Kataoka; Naomi Morita; Daisuke Maruyama; Tetsu Satow; Koji Iihara; Jun C Takahashi

  Journal of neurosurgery 126 1 1 - 7 2017年01月 

  OBJECTIVE Transient neurological symptoms are frequently observed during the early postoperative period after direct bypass surgery for moyamoya disease. Abnormal signal changes in the cerebral cortex can be seen in postoperative MR images. The purpose of this study was to reveal the radiological features of the "cortical hyperintensity belt (CHB) sign" in postoperative FLAIR images and to verify its relationship to transient neurological events (TNEs) and regional cerebral blood flow (rCBF). METHODS A total of 141 hemispheres in 107 consecutive patients with moyamoya disease who had undergone direct bypass surgery were analyzed. In all cases, FLAIR images were obtained during postoperative days (PODs) 1-3 and during the chronic period (3.2 ± 1.13 months after surgery). The CHB sign was defined as an intraparenchymal high-intensity signal within the cortex of the surgically treated hemisphere with no infarction or hemorrhage present. The territory of the middle cerebral artery was divided into anterior and posterior parts, with the extent of the CHB sign in each part scored as 0 for none; 1 for presence in less than half of the part; and 2 for presence in more than half of the part. The sum of these scores provided the CHB score (0-4). TNEs were defined as reversible neurological deficits detected both objectively and subjectively. The rCBF was measured with SPECT using N-isopropyl-p-[123I]iodoamphetamine before surgery and during PODs 1-3. The rCBF increase ratio was calculated by comparing the pre- and postoperative count activity. RESULTS Cortical hyperintensity belt signs were detected in 112 cases (79.4%) and all disappeared during the chronic period. Although all bypass grafts were anastomosed to the anterior part of the middle cerebral artery territory, CHB signs were much more pronounced in the posterior part (p < 0.0001). TNEs were observed in 86 cases (61.0%). Patients with TNEs showed significantly higher CHB scores than those without (2.31 ± 0.13 vs 1.24 ± 0.16, p < 0.0001). The CHB score, on the other hand, showed no relationship with the rCBF increase ratio (p = 0.775). In addition, the rCBF increase ratio did not differ between those patients with TNEs and those without (1.15 ± 0.033 vs 1.16 ± 0.037, p = 0.978). CONCLUSIONS The findings strongly suggest that the presence of the CHB sign during PODs 1-3 can be a predictor of TNEs after bypass surgery for moyamoya disease. On the other hand, presence of this sign appears to have no direct relationship with the postoperative local hyperperfusion phenomenon. Vasogenic edema can be hypothesized as the pathophysiology of the CHB sign, because the sign was transient and never accompanied by infarction in the present series.
• Histopathologic Analysis of Retrieved Thrombi Associated With Successful Reperfusion After Acute Stroke Thrombectomy.

  Tetsuya Hashimoto; Mikito Hayakawa; Naoko Funatsu; Hiroshi Yamagami; Tetsu Satow; Jun C Takahashi; Kazuyuki Nagatsuka; Hatsue Ishibashi-Ueda; Jun-Ichi Kira; Kazunori Toyoda

  Stroke 47 12 3035 - 3037 2016年12月 

  BACKGROUND AND PURPOSE: Histopathologic evaluation of occlusive thrombi retrieved from cerebral arteries using endovascular therapy is possible. We investigated the relationship between successful reperfusion after thrombectomy and histopathologic characteristics of retrieved thrombi. METHODS: Among consecutive patients with acute ischemic stroke treated with endovascular therapy at our institute from December 2010 to July 2015, we retrospectively reviewed those with acute major arterial occlusion from which retrieved thrombi were evaluated histopathologically. Obtained thrombi were assessed for the existence of atheromatous gruel, organization, and the ratios of erythrocyte and fibrin/platelet components. Successful reperfusion was defined as the modified Treatment in Cerebral Ischemia grade of 2b to 3. RESULTS: Of 83 patients studied, 58 (70%) underwent successful reperfusion. Atheromatous gruel was less frequently identified (3% versus 20%; P=0.024), and the proportion of erythrocyte components was higher (57±23% versus 47±24%; P=0.042) in thrombi retrieved from the reperfused than the unreperfused group. On multivariate logistic regression analysis, atheromatous gruel was inversely related (odds ratio, 0.062; 95% confidence interval, 0.002-0.864), and >64% erythrocyte components (cutoff obtained from receiver operating characteristic curve) were positively related (odds ratio, 4.352; 95% confidence interval, 1.185-19.363) to successful reperfusion. CONCLUSIONS: Successful reperfusion could be associated with the histopathology of occlusive thrombi, including the existence of atheromatous gruel and proportion of erythrocyte components. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02251665.
• Development of in vivo tissue-engineered microvascular grafts with an ultra small diameter of 0.6 mm (MicroBiotubes): acute phase evaluation by optical coherence tomography and magnetic resonance angiography.

  Daizo Ishii; Jun-Ichiro Enmi; Takeshi Moriwaki; Hastue Ishibashi-Ueda; Mari Kobayashi; Shinichi Iwana; Hidehiro Iida; Tetsu Satow; Jun C Takahashi; Kaoru Kurisu; Yasuhide Nakayama

  Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs 19 3 262 - 9 2016年09月 

  Biotubes, i.e., in vivo tissue-engineered connective tubular tissues, are known to be effective as vascular replacement grafts with a diameter greater than several millimeters. However, the performance of biotubes with smaller diameters is less clear. In this study, MicroBiotubes with diameters <1 mm were prepared, and their patency was evaluated noninvasively by optical coherence tomography (OCT) and magnetic resonance angiography (MRA). MicroBiotube molds, containing seven stainless wires (diameter 0.5 mm) covered with silicone tubes (outer diameter 0.6 mm) per mold, were embedded into the dorsal subcutaneous pouches of rats. After 2 months, the molds were harvested with the surrounding capsular tissues to obtain seven MicroBiotubes (internal diameter 0.59 ± 0.015 mm, burst pressure 4190 ± 1117 mmHg). Ten-mm-long MicroBiotubes were allogenically implanted into the femoral arteries of rats by end-to-end anastomosis. Cross-sectional OCT imaging demonstrated the patency of the MicroBiotubes immediately after implantation. In a 1-month follow-up MRA, high patency (83.3 %, n = 6) was observed without stenosis, aneurysmal dilation, or elongation. Native-like vascular structure was reconstructed with completely endothelialized luminal surfaces, mesh-like elastin fiber networks, regular circumferential orientation of collagen fibers, and α-SMA-positive cells. Although the long-term patency of MicroBiotubes still needs to be confirmed, they may be useful as an alternative ultra-small-caliber vascular substitute.
• Superselective Provocative Test with Propofol Using Motor-Evoked Potential Monitoring for Managing Cerebral Arteriovenous Malformations Fed by the Anterior Choroidal Artery.

  Makoto Isozaki; Tetsu Satow; Toshinori Matsushige; Hisae Mori; Koji Iihara

  Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association 25 9 e153-7  2016年09月 

  When feeder artery obliteration is performed via an endovascular procedure to treat cerebral arteriovenous malformation (AVM), it is important to prevent the ischemic complications that are associated with feeder occlusion. A provocative test may be beneficial in some cases to protect against ischemic complications. We report the case of a 57-year-old man who developed an intracerebral hematoma in the left internal temporal lobe and who had an AVM with a varix in the ambient cistern, which was primarily fed by a branch of the left anterior choroidal artery (AChA) and the posterior lateral choroidal artery, and drained into the basal vein. Therefore, we planned endovascular obliteration of the AChA, followed by gamma knife radiosurgery for the residual posterior component. The patient underwent a superselective provocative test with a 3 mg of propofol under general anesthesia using motor-evoked potential monitoring. The feeder embolization was performed as planned after the provocative test, and the patient exhibited no neurological deficits, such as hemiparesis, during the procedure.
• Construction of 3 animal experimental models in the development of honeycomb microporous covered stents for the treatment of large wide-necked cerebral aneurysms.

  Yasuhide Nakayama; Tetsu Satow; Marina Funayama; Takeshi Moriwaki; Tsutomu Tajikawa; Maya Furukoshi; Eika Hamano; Daizo Ishi; Masataka Hayashi; Sei Sugata; Hatsue Ishibashi-Ueda; Jun C Takahashi

  Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs 19 2 179 - 87 2016年06月 

  The treatment of large or wide-necked cerebral aneurysms is extremely difficult, and carries a high risk of rupture, even when surgical or endovascular methods are available. We are developing novel honeycomb microporous covered stents for treating such aneurysms. In this study, 3 experimental animal models were designed and evaluated quantitatively before preclinical study. The stents were prepared using specially designed balloon-expandable stents (diameter 3.5-5.0 mm, length 16-28 mm) by dip-coating to completely cover their struts with polyurethane film (thickness 20 µm) and microprocessing to form the honeycomb pattern after expansion. (1) In an internal carotid artery canine model (n = 4), all stents mounted on the delivery catheter passed smoothly through the tortuous vessel with minimal arterial damage. (2) In an the large, wide-necked, outer-sidewall aneurysm canine model, almost all parts of the aneurysms had embolized immediately after stenting (n = 4), and histological examination at 2 months revealed neointimal formation with complete endothelialization at all stented segments and entirely organized aneurysms. (3) In a perforating artery rabbit model, all lumbar arteries remained patent (n = 3), with minimal change in the vascular flow pattern for over 1 year, even after placement of a second, overlapping stent (n = 3). At 2 months after stenting, the luminal surface was covered with complete thin neointimal formation. Excellent embolization performance of the honeycomb microporous covered stents without disturbing branching flow was confirmed at the aneurysms in this proof-of-concept study.
• Training guidelines for endovascular stroke intervention: an international multi-society consensus document

  S. D. Lavine; K. Cockroft; B. Hoh; N. Bambakidis; A. A. Khalessi; H. Woo; H. Riina; A. Siddiqui; J. A. Hirsch; W. Chong; H. Rice; J. Wenderoth; P. Mitchell; A. Coulthard; T. J. Signh; C. Phatorous; M. Khangure; P. Klurfan; K. ter Brugge; D Iancu; T. Gunnarsson; O. Jansen; M. Muto; I. Szikora; L. Pierot; P. Brouwer; J. Gralla; S. Renowden; T. Andersson; J. Fiehler; F. Turjman; P. White; A. C. Januel; L. Spelle; Z. Kulcsar; R. Chapot; A. Biondi; S. Dima; C. Taschner; M. Szajner; A. Krajina; N. Sakai; Y. Matsumaru; S. Yoshimura; M. Ezura; T. Fujinaka; K. Iihara; A. Ishii; T. Higashi; M. Hirohata; A. Hyodo; Y. Ito; M. Kawanishi; H. Kiyosue; E. Kobayashi; S. Kobayashi; N. Kuwayama; Y. Matsumoto; S. Miyachi; Y. Murayama; I. Nagata; I. Nakahara; S. Nemoto; Y. Niimi; H. Oishi; J. Satomi; T. Satow; K. Sugiu; M. Tanaka; T. Terada; H. Yamagami; O. Diaz; P. Lylyk; M. V. Jayaraman; A. Patsalides; C. D. Gandhi; S. K. Lee; T. Abruzzo; B. Albani; S. A. Ansari; A. S. Arthur; B. W. Baxter; K. R. Bulsara; M. Chen; J. E. Delgado Almandoz; J. F. Fraser; D. V. Heck; S. W. Hetts; M. S. Hussain; R. P. Klucznik; T. M. Leslie-Mawzi; W. J. Mack; R. A. McTaggart; P. M. Meyers; J. Mocco; C. J. Prestigiacomo; G. L. Pride; P. A. Rasmussen; R. M. Starke; P. J. Sunenshine; R. W. Tarr; D. F. Frei; M. Ribo; R. G. Nogueira; O. O. Zaidat; T. Jovin; I. Linfante; D. Yavagal; D. Liebeskind; R. Novakovic; S. Pongpech; G. Rodesch; M. Soderman; A. Taylor; T. Krings; D. Orbach; L. Picard; D. C. Suh; H. Q. Zhang

  Neuroradiology 58 6 537 - 541 2016年04月
• Judgment and action in surgery for unruptured intracranial aneurysms

  Jun C. Takahashi; Hiroharu Kataoka; Tetsu Satow; Hisae Mori

  Japanese Journal of Neurosurgery 25 1 4 - 14 2016年01月 [査読有り]
   

  Recent multicenter-prospective studies on unruptured intracranial aneurysms have demonstrated their annual and cumulative rupture rates in detail. These data have been mainly presented according to the location, size, and shape of the aneurysms. It is especially notable that the rupture rates in the Japanese population are significantly higher than those in the West. In the clinical field especially, the therapeutic decision for unruptured aneurysms should be based on these up-to-date data to prevent their rupture. In addition, every neurosurgeon should consider the specific problems of each patient including their life expectancy, possible systemic diseases and health-related quality of life. On the macroscopic point of view, a radical reduction in the number of domestic subarachnoid hemorrhage seems to be quite difficult to achieve when it is solely based on the conventional “Find and Treat” strategy. A simple simulation can show that this strategy requires an extremely large population to be screened to find medium-to large sized aneurysms which are prone to rupture. Only a novel paradigm of the therapeutic management of intracranial aneurysms will solve this problem in the future.
• Relationship between histologic features and outcomes of carotid revascularization for radiation-induced stenosis.

  Noritaka Sano; Tetsu Satow; Daisuke Maruyama; Hiroharu Kataoka; Ken-ichi Morita; Hatsue Ishibashi-Ueda; Koji Iihara

  Journal of vascular surgery 62 2 370 - 7 2015年08月 

  OBJECTIVE: This study aimed to elucidate the relationships between preoperative carotid imaging results, histologic characteristics, and surgical treatment outcomes of radiation-induced carotid stenosis (RICS), using control subjects without RICS for comparison. METHODS: We retrospectively reviewed records of 17 patients who underwent carotid revascularization for 22 instances of RICS, including 10 cases of carotid artery stenting (CAS), 11 cases of carotid endarterectomy (CEA), and 1 case of CEA with retrograde CAS, between July 2004 and April 2013. The controls were 475 patients with no history of radiation therapy who underwent carotid revascularization in a similar period. Preoperative magnetic resonance imaging (MRI), ultrasonography (US), and computed tomography angiography results were correlated with outcomes of histologic analysis of CEA specimens. End points included ipsilateral and contralateral stroke, myocardial infarction, restenosis, in-stent thrombosis, and target lesion revascularization. RESULTS: Vulnerable plaques on carotid MRI (86% vs 64.2%; P = .010) and mobile (27% vs 8.0%; P = .008) and ulcerative (50% vs 15.8%; P < .001) plaques on US were more frequent in the RICS group. All revascularization procedures were successful, and no occlusion occurred. Adverse events in the CAS group, including one minor stroke and one transient ischemic attack within 30 days as well as five ipsilateral neurologic events after 30 days, including three minor strokes and two transient ischemic attacks, were significantly more frequent than in the CEA group. All three cases of late ipsilateral stroke displayed vulnerable plaque on preoperative MRI and late in-stent thrombosis or restenosis on US. CONCLUSIONS: Our radiologic and histologic analyses revealed that advanced RICS is often accompanied by formation of vulnerable plaque. CEA can prevent undesirable late outcomes in such cases.
• Efficacy of FLOW 800 with indocyanine green videoangiography for the quantitative assessment of flow dynamics in cerebral arteriovenous malformation surgery.

  Kenji Fukuda; Hiroharu Kataoka; Norio Nakajima; Jun Masuoka; Tetsu Satow; Koji Iihara

  World neurosurgery 83 2 203 - 10 2015年02月 

  OBJECTIVE: To evaluate the quantitative assessment of flow dynamics during surgery for arteriovenous malformations (AVMs) with FLOW 800 with indocyanine green videoangiography. METHODS: Changes in flow dynamics in the superficial AVM components (feeder, nidus, and drainer), the adjacent cortical artery, and the cortical vein surrounding AVM were evaluated. Analysis was performed at predissection, postclipping of the feeders, and postresection of the nidus with the use of quantitative values of the maximum fluorescence intensity, time to half-maximum fluorescence intensity (T1/2 FI), and the fluorescence intensity rate at T1/2 FI semiautomatically obtained with the use of FLOW 800 software. RESULTS: FLOW 800 assessments were performed in 7 cases. The time difference between the T1/2 FI, defined as transit time, in the cortical artery and the drainer was prolonged from 0.08 ± 0.65 seconds to 2.63 ± 1.79 seconds (P < 0.0001) at postfeeder clipping phase. The transit time between the cortical artery and the cortical vein was reduced to 3.76 ± 1.37 seconds at post feeder clipping phase (P = 0.024) and 2.63 ± 0.80 seconds at final phase (P = 0.005) compared with 4.56 ± 1.47 seconds at predissection phase. The maximum intensity and the fluorescence intensity rate at T1/2 FI were not significantly different at these phases, excluding the maximum intensity of the drainer decreasing from 533 ± 271 to 399 ± 217 (P = 0.006) at post feeder clipping phase. CONCLUSION: FLOW 800 analysis with indocyanine green videoangiography provides the real-time hemodynamic status of the AVMs and adjacent brain at various stages of resection. This technique is feasible to resect AVMs more safely and convincingly.
• Efficacy of cilostazol in prevention of bradycardia during carotid artery stenting.

  Daizo Ishii; Tetsu Satow; Kenichi Murao; Kunihiro Nishimura; Koji Iihara

  Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association 23 4 662 - 6 2014年04月 

  BACKGROUND: Hypotension and bradycardia are known to occur frequently in carotid artery stenting (CAS), which may lead to postprocedural complications. The purpose of this retrospective study was to assess the efficacy of cilostazol, a phosphodiesterase 3 inhibitor, for preventing bradycardia and hypotension in the periprocedural period. METHODS: The study population comprised 53 patients (54 lesions) with carotid artery stenosis who underwent CAS at our institution between 2004 and 2008. The patients were categorized by the use (group C, n = 26) or nonuse of cilostazol (group N, n = 28). The incidences of intraprocedural and postprocedural hypotension and bradycardia in each group were statistically assessed. RESULTS: Intraprocedural hypotension and bradycardia occurred in 9 cases (34.6%) and 4 cases (15.3%) in group C and in 5 cases (17.9%) and 15 cases (53.6%) in group N, respectively. Postprocedural hypotension and bradycardia occurred in 4 cases (15.4%) and 0 cases in group C and in 1 case (3.6%) and 3 cases (10.7%) in group N, respectively. The incidence of intraprocedural bradycardia (IBc) was significantly lower in group C (P = .0035). Logistic regression analysis revealed that the use of cilostazol decreased the risk of IBc 99.5% (odds ratio [OR] = .01, 95% confidence interval [CI]: 5.46 × 10(-6) to .04, P = .001) and distance from carotid bifurcation to maximum stenotic lesion was independently associated with IBc (OR = .46, 95% CI: .29-.74, P = .001). CONCLUSION: Use of cilostazol was associated with a lower incidence of IBc. Cilostazol may be a useful drug for the prevention of this complication.
• Fatal multiple systemic emboli after intravenous thrombolysis for cardioembolic stroke.

  Koji Tanaka; Tomoyuki Ohara; Akiko Ishigami; Yoshihiko Ikeda; Toshinori Matsushige; Tetsu Satow; Hatsue Ishibashi-Ueda; Koji Iihara; Kazunori Toyoda

  Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association 23 2 395 - 7 2014年02月 

  Our objective is to present a case of fatal multiple systemic emboli after intravenous thrombolysis for cardioembolic stroke. A 64-year-old woman with atrial fibrillation was admitted for evaluation of sudden consciousness disturbance, right hemiplegia, and aphasia. Diffusion-weighted imaging showed no early ischemic changes of the brain, and magnetic resonance angiography (MRA) showed occlusion of the left middle cerebral artery (MCA). One hour after initiation of 0.6 mg/kg of intravenous alteplase, the MCA was partially recanalized. Her symptoms disappeared the following day. We began intravenous heparin for secondary prevention of cardioembolic stroke. However, on the third day (52 hours after thrombolysis), she suddenly developed a coma and left hemiplegia. MRA showed acute occlusion of the right internal carotid artery (ICA). She developed acute kidney injury and sudden shock and then died of fatal cardiorespiratory arrest on the fourth day. Autopsy revealed occlusion of the mitral valve orifice by a spherical fresh red thrombus that led from the left atrial appendage. Acute embolic infarcts were identified in the spleen and right kidney, the latter secondary to occlusion of the right renal artery with fresh red thrombus. Intravenous thrombolysis and subsequent anticoagulation therapy may destabilize pre-existing intracardiac thrombus, potentially leading to recurrent stroke, multiple systemic embolisms, and the fatal "hole-in-one" effect.
• Endovascular Treatment for Ruptured Vertebral Artery Dissecting Aneurysms: Results from Japanese Registry of Neuroendovascular Therapy (JR-NET) 1 and 2.

  Tetsu Satow; Daizo Ishii; Koji Iihara; Nobuyuki Sakai

  Neurologia medico-chirurgica 54 Suppl 2 2 98 - 106 2014年 

  In treating ruptured vertebral artery dissecting aneurysms (VADAs), neuroendovascular therapy (NET) represented by coil obliteration is considered to be a reliable intervention. However, there has been no multi-center based study in this setting so far. In this article, results of NET for ruptured VADA obtained from Japanese Registry of Neuroendovascular Therapy (JR-NET) 1 and 2 were assessed to elucidate the factors associated with favorable outcome. A total of 213 in JR-NET1 and 381 patients in JR-NET2 with ruptured VADA were included, and they were separately analyzed because several important datasets such as vasospasm and site of dissecting aneurysms in relation to the posterior inferior cerebellar artery (PICA) were collected only in JR-NET1. The ratio of poor World Federation of Neurosurgical Societies (WFNS) grade (4 and 5) was 48.8% and 53.9%, and the ratio of favorable outcome (modified Rankin scale, mRS 0 to 2) at 30 days after onset was 61.1 % and 49.1% in JR-NET1 and 2, respectively. In both studies, poor WFNS grade and procedural complication were independently correlated as negative factors for favorable outcome. In JR-NET1, PICA-involved lesion was also designated as a negative factor while elderly age and absence of postprocedural antithrombotic therapy was detected as other negative factors in JR-NET2. The ratios of favorable outcome in poor grade patients were 25.4% in JR-NET1 and 31.3% in JR-NET2, which seemed compatible with the previous studies. These results may provide a baseline data for the NET in this disease and could be useful for validating the benefits of novel devices.
• Recent trends in neuroendovascular therapy in Japan: analysis of a nationwide survey--Japanese Registry of Neuroendovascular Therapy (JR-NET) 1 and 2.

  Nobuyuki Sakai; Shinichi Yoshimura; Waro Taki; Akio Hyodo; Shigeru Miyachi; Yoji Nagai; Chiaki Sakai; Tetsu Satow; Tomoaki Terada; Masayuki Ezura; Toshio Hyogo; Shunji Matsubara; Kentaro Hayashi; Toshiyuki Fujinaka; Yasushi Ito; Shigeki Kobayashi; Masaki Komiyama; Naoya Kuwayama; Yuji Matsumaru; Yasushi Matsumoto; Yuichi Murayama; Ichiro Nakahara; Shigeru Nemoto; Koichi Satoh; Kenji Sugiu; Akira Ishii; Hirotoshi Imamura

  Neurologia medico-chirurgica 54 Suppl 2 1 1 - 8 2014年 

  The present study retrospectively analyzed the database of the Japanese Registry of Neuroendovascular Therapy 1 and 2 (JR-NET1&2) to determine annual trends, including adverse events and clinical outcomes at 30 days after undergoing neuroendovascular therapy. JR-NET1&2 are surveys that targeted all patients in Japan who underwent neuroendovascular therapy delivered by physicians certified by the Japanese Society of Neuroendovascular Therapy (JSNET) between 2005 and 2009. Medical information about the patients was anonymized and retrospectively registered via a website. Data from 32,608 patients were analyzed. The number of treated patients constantly increased from 5,040 in 2005 to 7,406 in 2009 and the rate of octogenarians increased from 7.0% in 2005 to 10.4% in 2009. The proportion of procedures remained relatively constant, but ratios of angioplasty slightly increased from 32.8% in 2005 to 33.7% in 2009. Procedural complications were associated more frequently with acute stroke (9.6%), ruptured aneurysms (7.4%), intracranial artery disease (ICAD) (5.4%), and arteriovenous malformation (AVM, 5.2%). The number of patients requiring neuroendovascular treatment in Japan is increasing and the outcomes of such therapy are clinically acceptable. Details of each type of treatment will be investigated in sub-analyses of the database.
• Successful flow reduction surgery for a ruptured true posterior communicating artery aneurysm caused by the common carotid artery ligation for epistaxis.

  Yukihiro Yamao; Jun C Takahashi; Tetsu Satow; Koji Iihara; Susumu Miyamoto

  Surgical neurology international 5 Suppl 14 S501-5  2014年 

  BACKGROUND: Carotid artery occlusion can lead to the development of rare true posterior communicating artery (PCoA) aneurysms because of hemodynamic stress on the PCoA. Surgical treatment of these lesions is challenging. CASE DESCRIPTION: The authors report a case of a true PCoA aneurysm that developed and ruptured 37 years after ligation of the ipsilateral common carotid artery for epistaxis. The lesion was successfully treated with clipping of the distal M1 segment of the middle cerebral artery (MCA) after the occipital artery-radial artery free graft-MCA bypass, which led to extreme reduction in collateral flow through the PCoA. A cortical branch, located just proximal to the obliteration site, functioned as a sufficient flow outlet. The aneurysm shrank, and the patient has been doing well without any symptoms for 5 years after surgery. CONCLUSIONS: M1 obliteration combined with high-flow extra-intracranial bypass might be a promising option for a true PCoA aneurysm, and therapeutic design that leaves a sufficient flow outlet on the M1 is mandatory to avoid unexpected occlusion of the M1 and its perforators.
• Hybrid operating room for the treatment of complex neurovascular and brachiocephalic lesions.

  Koji Iihara; Tetsu Satow; Toshinori Matsushige; Hiroharu Kataoka; Norio Nakajima; Kenji Fukuda; Makoto Isozaki; Daisuke Maruyama; Takuro Nakae; Nobuo Hashimoto

  Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association 22 8 e277-85  2013年11月 

  BACKGROUND: We examine the impact of the installation of integrated hybrid operating rooms (ORs) that allow both surgical and endovascular procedures and are designed for less invasive and 1-stage treatment of complex neurovascular lesions. METHODS: We retrospectively analyzed our experience in the treatment of complex neurovascular lesions in a hybrid OR. RESULTS: Three patients with distal middle cerebral artery (MCA) aneurysms underwent a proximal clip occlusion or endovascular trapping with a superficial temporal artery-MCA bypass after correct localization of the recipient branch distal to the aneurysm using superselective intra-arterial infusion of indocyanine green under an operating microscope. Two patients with innominate artery stenosis were treated with retrograde stenting from the common carotid artery (CCA) with distal protection of the internal carotid artery (ICA) alone, and with antegrade stenting with dual protection of the ipsilateral ICA and the vertebral artery. Two patients with tandem stenosis of the proximal CCA and carotid bifurcation underwent 1-stage retrograde stenting combined with a carotid endarterectomy. A patient with the innominate artery and the proximal CCA stenosis underwent staged percutaneous antegrade angioplasty of the innominate artery followed by retrograde stenting of both lesions. A patient with tandem stenosis of the subclavian and innominate arteries underwent 1-stage retrograde stenting. In 2 patients with carotid stenosis that was difficult to access via the endovascular route, carotid stenting was performed by direct puncture of the proximal CCA. No patients suffered from new postoperative neurologic deficits. CONCLUSIONS: The integration of a high-end hybrid OR enables combined endovascular and surgical procedures for complex neurovascular and brachiocephalic lesions in a 1-stage treatment.
• Incidence and risk factors of chronic subdural hematoma after aneurysmal clipping.

  Takayuki Ohno; Koji Iihara; Jun C Takahashi; Norio Nakajima; Tetsu Satow; Tomohito Hishikawa; Izumi Nagata; Kazuo Yamada; Susumu Miyamoto

  World neurosurgery 80 5 534 - 7 2013年11月 

  OBJECTIVE: Chronic subdural hematoma (CSDH) after aneurysmal clipping is a rare complication, but its incidence and risk factors are not known in detail. We retrospectively reviewed our cases requiring surgery for CSDH after clipping. METHODS: In our hospital, between January 2000 and December 2006, 794 patients (unruptured, 58.0%) underwent clipping surgery for aneurysm of the anterior circulation. We reviewed incidence and risk factors of CSDH after clipping. For the past 2 years, we reviewed all computed tomography scans for 163 unruptured aneurysms, and examined the relationship between an increase of subdural fluid collection (SFC) and development of CSDH. RESULTS: Fifteen patients (1.9%) developed CSDH after clipping, which required evacuation. Among those, 13 had unruptured aneurysms (2.8%), a much higher percentage than for ruptured aneurysms (0.9%). On univariate statistical analysis, risk factors of CSDH were associated with advanced age (P = 0.0005), male gender (P = 0.04), and unruptured aneurysms (P = 0.02). Aneurysmal location was not related to the development of postoperative CSDH. Contralateral CSDH occurred in 3 patients, but no middle cerebral artery aneurysm developed contralateral CSDH. An increase in postoperative SFC during 1 week was a significant risk factor for CSDH (P = 0.001). CONCLUSIONS: In addition to the classic risk factors, this study showed that clipping for unruptured aneurysms carries a higher risk for CSDH compared to ruptured aneurysms. We suggest that an increase of SFC during 1 week postoperatively can be a factor in predicting CSDH after clipping.
• Superselective shunt occlusion for the treatment of cavernous sinus dural arteriovenous fistulae.

  Tetsu Satow; Kenichi Murao; Toshinori Matsushige; Kenji Fukuda; Susumu Miyamoto; Koji Iihara

  Neurosurgery 73 1 Suppl Operative ons100-5  2013年09月 

  BACKGROUND: In treating cavernous sinus dural arteriovenous fistulae (CSdAVFs), transvenous embolization of the whole affected sinus is usually performed, which may result in the disturbance of normal venous drainage or permanent cranial nerve palsy. OBJECTIVE: To describe superselective shunt occlusion of CSdAVFs. METHODS: Between July 2005 and August 2011, we had 20 consecutive cases of CSdAVFs. In 14 cases (70%), we could detect the restricted locus of arteriovenous shunts by 3-dimensional rotational angiography and/or superselective arteriography. After navigating the microcatheter to the shunt segment, consecutive superselective arteriovenography was performed to confirm the location of the microcatheter at the proper position. RESULTS: In 12 of 14 cases (85.7%) in which the shunt was restricted, coiling only in the small venous pouch or compartment, which was just downstream of the shunt point, led to complete disappearance of the shunt without obliterating the entire sinus. No recurrence or permanent cranial nerve palsy was observed during the follow-up period with a mean of 46 months (range, 3-69 months) in 12 cases treated by superselective shunt occlusion. CONCLUSION: This technique, which enables complete extirpation of shunts by small amounts of coils, is a feasible way to treat CSdAVFs with excellent mid- to long-term results. Understanding of the angioarchitecture by 3-dimensional rotational angiography and consecutive superselective arteriovenography was useful. This method should be considered before sinus packing or mere obliteration of dangerous venous outlets.
• Efficacy and safety of single versus dual antiplatelet therapy for coiling of unruptured aneurysms.

  Yusuke Nishikawa; Tetsu Satow; Toshinori Takagi; Kenichi Murao; Susumu Miyamoto; Koji Iihara

  Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association 22 5 650 - 5 2013年07月 

  BACKGROUND: Although the efficacy of antiplatelet therapy for coiling of unruptured cerebral aneurysms has been reported, regimens for this therapy are not yet well established. The aim of this retrospective study was to analyze correlations among the modes of antiplatelet use, aneurysmal configuration, coiling methods, and complications to elucidate the optimal antiplatelet therapy for coiling. METHODS: The study population comprised 154 patients with unruptured aneurysms who underwent coiling with antiplatelet therapy at our institution between 2001 and 2009. The patients were categorized by mode of antiplatelet therapy (single [n = 64] or dual [n = 90]), neck size (wide [n = 80] or narrow [n = 74]), and technique used (simple [n = 42] or adjunctive [n = 112]). The incidences of hemorrhagic/ischemic complications and abnormalities on postprocedural diffusion-weighted magnetic resonance imaging (DWI) in each group were statistically assessed. RESULTS: Hemorrhagic complications occurred in 1 case (1.5%) with single antiplatelet therapy and in 2 cases (2.2%) with dual antiplatelet therapy. Symptomatic ischemic complications occurred in 5 cases (7.8%) with single therapy and in 4 cases (4.4%) with dual therapy. Abnormalities were detected by DWI in 27 cases (42%) with single therapy and in 31 cases (34%) with dual therapy. No significant difference was found between modes of antiplatelet therapy even when the technique used was taken into account. In cases of wide neck, however, there were significant differences in the rate of symptomatic ischemic complications (single, 21.7%; dual, 3.5%; P = .014) and DWI abnormalities (single, 37.8%; dual, 20.9%; P = .048). CONCLUSION: Our data suggest that dual antiplatelet therapy may better prevent ischemic complications from coiling for wide-necked aneurysms compared with single antiplatelet therapy.
• Haptoglobin phenotype predicts cerebral vasospasm and clinical deterioration after aneurysmal subarachnoid hemorrhage.

  Hiroyuki Ohnishi; Koji Iihara; Yasuyuki Kaku; Keita Yamauchi; Kenji Fukuda; Kunihiro Nishimura; Michikazu Nakai; Tetsu Satow; Norio Nakajima; Masaya Ikegawa

  Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association 22 4 520 - 6 2013年05月 

  Vasospasm (VS) and delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) are thought to greatly affect prognosis. Haptoglobin (Hp) is a hemoglobin-binding protein expressed by a genetic polymorphism (1-1, 2-1, and 2-2). Our objects were to investigate whether the Hp phenotype could predict the incidence of cerebral infarction, favorable outcome, clinical deterioration by DCI, and angiographical VS after aneurysmal SAH. Ninety-five consecutive patients who underwent clipping or coil embolization were studied. Favorable functional outcome was defined as a modified Rankin Scale score of 0-2 at 3 months. Angiographical VS was diagnosed based on cerebral angiography findings performed between days 7 and 10 after SAH. The Hp 2-2 group had a significantly greater risk of angiographical VS than that of Hp 2-1 and 1-1 groups combined on univariate (odds ratio [OR]: 3.60, confidence interval [CI]: 1.49-8.67, P = .003) and multivariate logistic regression analyses after being adjusted for age, sex, Fisher groups, and other risk factors (OR: 3.75, CI: 1.54-9.16, P = .004). The Hp 2-2 group also showed the tendency of a greater risk of clinical deterioration by DCI with marginal significance on univariate and age- and sex-adjusted analyses (univariate OR: 2.46, CI: .90-6.74, P = .080; age- and sex-adjusted OR: 2.46, CI: .89-6.82, P = .080) but not after being adjusted for other multiple risk factors. The Hp 2-2 group was not associated with the favorable 3-month outcome and cerebral infarction (univariate: P = .867, P = .209; multivariate: P = .905, P = .292). The Hp phenotype seems to be associated with a higher rate of angiographical VS and clinical deterioration by DCI but does not affect the incidence of cerebral infarction and favorable outcome.
• Radiation-induced carotid stenosis successfully treated with carotid endarterectomy

  Noritaka Sano; Kenji Fukuda; Tetsu Satow; Morio Takasaki; Kenichi Morita; Hiroharu Kataoka; Koji Iihara

  Japanese Journal of Neurosurgery 22 4 314 - 318 2013年04月 [査読有り]
   

  A 78-year-old man with a history of cervical radiation therapy for malignant lymphoma presented with disseminated cerebral infarctions in the left cerebral hemisphere. Five years before this episode, he had suffered from a right cerebral infarction due to right carotid artery stenosis with mobile plaque, and had undergone carotid artery stenting (CAS). Thereafter, despite the reinforcement of antiplatelet and anticoagulant therapy, he had experienced recurrent in- stent thrombosis and ipsilateral cerebral infarctions for more than three years. This time, we chose carotid endarterectomy (CEA) for the left stenotic lesion to remove the embolic source including mobile plaque at the carotid bifurcation. His postoperative course was uneventful, with no new neurological deficits. Radiation-induced carotid stenosis (RI-CS) used to be considered high risk for CEA, but recent reports suggest that the long- term clinical results of CAS for these lesions are inferior to those of CEA. CEA may be a promising alternative for the treatment of RI-CSs, depending on the plaque characteristics and previous surgical history involving the cervical region.
• [Research of postoperative complications after coil protrusions in embolization of unruptured cerebral aneurysms].

  Yukihiro Yamao; Tetsu Satow; Kenichi Murao; Susumu Miyamoto; Koji Iihara

  No shinkei geka. Neurological surgery 40 1 23 - 9 2012年01月 

  OBJECTIVES: Postoperative courses in "coil-protruded" cases in embolization of unruptured cerebral aneurysms remain unknown. The purpose of this study is to investigate postoperative complications after coil protrusions. METHODS: From May 2003 to December 2007, 90 consecutive cases with unruptured cerebral aneurysm treated by coil embolization were examined at National Cerebral and Cardiovascular Center. All patients received antiplatelet therapy prior to the procedure. The patterns of protrusions were classified into three; tail (T), loop (L), unraveled (U). RESULTS: Coil protrusions were observed in 17 cases (18.9%). Symptomatic ischemic complications occurred in 7 cases (7.8%). One case occurred in coil protrusions (group P) and 6 cases occurred in no coil protrusions (group N). Infarctions on MR diffusion-weighted image within 7 days after embolization were found in 10 cases (58.8%) in group P and in 28 cases (38.4%) in group N. Infarction on MR fluid attenuated inversion recovery 7 days or later were found in 0 in group P, and in 4 (5.5%) in group N. There were no significant differences. The number of each protrusion pattern was as follows: T was 12 cases, L was 3 cases and U was 2 cases. Symptomatic ischemia was observed in one case (8.3%) in T. Infarctions on MR diffusion-weighted image within 7 days after embolization were found in 7 (58.3%), 1 (33.3%) and 2 (100%), respectively. There were no significant differences between the three morphological patterns. CONCLUSION: In this retrospective study, coil protrusion after embolization of unruptured cerebral aneurysms on antiplatelet therapy, did not increase the incidence of ischemic complications.
• [Carotid artery stenting for radiation-induced carotid stenosis].

  Yusuke Egashira; Tetsu Satow; Kosuke Masuda; Masakazu Okawa; Hiroyuki Ohnishi; Takahito Okazaki; Jun C Takahashi; Ken-Ichi Murao; Koji Iihara; Susumu Miyamoto

  No shinkei geka. Neurological surgery 38 10 913 - 20 2010年10月 

  PURPOSE AND METHODS: To evaluate the outcome and lesion characteristics in patients with radiation induced carotid stenoses (RI-CS) treated by carotid artery stenting (CAS), a total of five patients with RI-CS (six lesions) were retrospectively analyzed. RESULTS: Four lesions had their most stenotic site at the common carotid artery (CCA). All cases had contralateral carotid or vertebral artery stenosis (>50%). All patients had risk factors of atherosclerosis and all lesions contained unstable plaques at the stenotic site. A total of seven procedures were carried out and procedural success was obtained in all cases. Asymptomatic embolic infarctions associated with procedure were observed in four cases by diffusion-weighted MR imaging. In-stent thrombi were observed in two cases, one of which developed a neurological symptom three days after the procedure. CONCLUSION: CAS is a technically successful intervention for RI-CS. Care should be taken according to the characteristics of the plaque, which usually is vulnerable and long. Appropriate choice of a protection method could help in the reduction of unfavorable embolic complications and close postoperative follow up is mandatory.
• Treatment strategy for ruptured aneurysms originating from the anterior wall of the internal carotid artery

  Takayuki Oono; Koji Iihara; Jun C. Takahashi; Norio Nakajima; Tetsu Satow; Hidekazu Takada; Tomohito Hishikawa; Takeshi Funaki; Masakazu Okawa; Yusuke Egashira; Kosuke Masuda; Izumi Nagata; Susumu Miyamoto

  Japanese Journal of Neurosurgery 18 6 450 - 457 2009年 [査読有り]
   

  The authors retrospectively reviewed their experience treating ruptured aneurysms originating from the anterior wall of the internal carotid artery in the acute stage after subarachnoid hemorrhage. Since 2002, there were 8 cases (mean age : 52 years old, three males) treated at our institution. Early in the study period, clipping was attempted in two cases, which were associated with intra- and post-operative rebleeding. Later, their strategy changed such that trapping of the aneurysms was the first choice of treatment, combined with STA-MCA bypass (4 cases) or high flow bypass using a radial artery graft (3 cases). Recently, the authors prefer to use high flow bypass more frequently, considering the possible occurrence of vasospasm on the collateral route shown at the initial angiograms. Specifically, vasospasm of the radial artery graft is another important issue to consider, even if pressure distension techniques are applied. If such vasospasm causes ischemic symptoms, percutaneous transluminal angioplasty should be performed in a timely fashion. Technical issues of surgical treatment of the anterior wall of the Internal carotid artery were discussed.
• Growth potential and response to multimodality treatment of partially thrombosed large or giant aneurysms in the posterior circulation.

  Koji Iihara; Kenichi Murao; Naoaki Yamada; Jun C Takahashi; Norio Nakajima; Tetsu Satow; Tomohito Hishikawa; Izumi Nagata; Susumu Miyamoto

  Neurosurgery 63 5 832 - 42 2008年11月 

  OBJECTIVE: This study examined the growth potential and response to multimodality treatment of partially thrombosed large or giant aneurysms in the posterior circulation. METHODS: The 17 aneurysms arose from nonbranching sites of the vertebral artery (VA) in 6 patients and from branching sites in 11 patients (the VA-posteroinferior cerebellar artery [PICA], 3 cases; basilar artery [BA] fenestration, 1 case; BA-superior cerebellar artery [SCA], 5 cases; and BA tip, 2 cases). RESULTS: Endovascular trapping was performed in 5 VA aneurysms at nonbranching sites, 2 VA-PICA cases with or without revascularization of the PICA, and 1 BA fenestration case. Endosaccular embolization was performed in 2 BA-SCA aneurysms as the sole treatment or after superficial temporal artery-SCA bypass for a broad-necked lesion. Surgical proximal occlusion (PO) with or without revascularization of the PICA was performed in 2 VA cases. Endovascular treatment failed to prevent growth in 1 VA-PICA case and the broad-necked BA-SCA case. Simple flow alteration by PO of 3 BA aneurysms, with gadolinium enhancement on T1-weighted images, did not prevent growth. Maximum flow reduction by various combinations of bypass (superficial temporal artery-posterior cerebral artery or superficial temporal artery-SCA) and BA PO, aimed at reducing hemodynamic stress on the neck, was tailored to 5 cases, including those refractory to PO; it achieved marked shrinkage in 2 cases and stabilization of the aneurysms in 3 cases. The aneurysms harboring neither gadolinium enhancement nor hyperintensity on fluid-attenuated inversion recovery images showed significantly lower growth potential before treatment and a lesser degree of shrinkage after tailored treatment than the remaining cases (P = 0.03 and P = 0.01, respectively). Overall, marked shrinkage was achieved in 27%, moderate shrinkage in 20%, stabilization in 47%, enlargement in 7%, and favorable outcome in 71%. Maximum flow reduction strategy for BA aneurysms tended to show higher shrinking efficacy than endovascular trapping for VA and BA aneurysms (P = 0.08). CONCLUSION: For aneurysms at nonbranching sites, endovascular trapping may be effective, although its shrinking efficacy may be moderate. For the most formidable BA aneurysms at branching sites, maximum flow reduction may cause marked shrinkage, even of aggressive lesions.
• [Therapeutic strategy for isolated dissecting aneurysms of the posterior inferior cerebellar artery: report of three cases and review of literature].

  Hidenori Seyama; Takeo Nishida; Munetaka Yamamoto; Hisae Mori; Tetsu Satow; Jun Yamada; Norio Nakajima; Jun C Takahashi; Koji Iihara; Kenichi Murao; Susumu Miyamoto

  No shinkei geka. Neurological surgery 34 10 1001 - 6 2006年10月 

  Dissecting aneurysm of the posterior inferior cerebellar artery (PICA) is a relatively rare disease and its treatment has not been well established. The authors analyzed the clinical and anatomical features of 38 reported lesions and three of our cases to clarify the "best therapeutic modality". The average age was 45.0 years old and 27 patients were male. Left-sided predominance (26 cases) was noted. As to the mode of onset, 23 cases were subarachnoid hemorrhage, 16 were ischemia, and 6 were Wallenberg's syndrome. Anatomically, the sites of dissection were located in the proximal segment of PICA in 31 lesions (75.6%). Review of the cases show that 30 (75%) patients underwent surgical therapy, and 7 (17.5%) patients underwent endovascular treatment. Twenty six patients who took surgical therapy and 5 patients who took endovascular treatment had excellent or good outcome. The critical point in therapeutic procedure is the preservation of perforating branches arising from PICA, therefore surgical trapping with the revascularization of PICA (usually extracranial-PICA anastomosis), in which these tiny branches are secured under microscopic manipulation, has the advantage in principle.
• Large paraclinoid aneurysm with a calcified neck treated by tailored multimodality procedures.

  Ken-ichiro Kikuta; Susumu Miyamoto; Tetsu Satow; Hiroharu Kataoka; Nobuo Hashimoto

  Neurologia medico-chirurgica 45 4 196 - 200 2005年04月 

  A 68-year-old woman presented with a large paraclinoid aneurysm with a calcified neck causing visual symptoms. Direct clipping was hazardous because of severe calcification of the neck. Endovascular internal trapping was difficult because of the short distance between the neck and the origin of the posterior communicating artery. Proximal occlusion was likely to be less effective because of large collateral back flow to the aneurysm via the ophthalmic artery (OphA). The aneurysm was successfully treated by a combination of a high-flow bypass, intraoperative coil embolization of the parent artery including the origin of the OphA, and clipping of the internal carotid artery distal to the aneurysm. Paraclinoid aneurysms may be difficult to treat by the simple application of direct clipping, endovascular coiling, or trapping. Multimodality procedures can be tailored to treat such aneurysms.
• Unilateral agenesis of internal carotid artery with ophthalmic artery arising from posterior communicating artery.

  Ramin M Naeini; Jitakshi De; Tetsu Satow; Goetz Benndorf

  AJR. American journal of roentgenology 184 2 571 - 3 2005年02月
• Techniques for passing the PercuSurge Guardwire system through severe and tortuous stenotic lesions.

  Tetsu Satow; Kazutomo Nakazawa; Tsuyoshi Ohta; Nobuo Hashimoto

  Neurologia medico-chirurgica 45 2 116 - 21 2005年02月 

  Distal embolism is one of the major causes of morbidity and mortality associated with treating stenotic lesions by endovascular procedures, such as percutaneous angioplasty and stenting. Many devices have been designed and used to prevent this complication. The PercuSurge Guardwire system is recognized as the best system available to prevent distal embolism during stenting. However, this system is sometimes hard to pass through severe stenotic, tortuous lesions because of the poor selectivity and support. The PercuSurge device was safely introduced into two cases of severe stenotic and tortuous lesions with a triple coaxial system and the buddy wire technique, and stenting was performed successfully. These techniques are very helpful for introducing and maintaining this system in the correct position across stenoses with unfavorable configurations.
• Endovascular recanalization of subclavian artery occlusions.

  Akiyo Sadato; Tetsu Satow; Akira Ishii; Tsuyoshi Ohta; Nobuo Hashimoto

  Neurologia medico-chirurgica 44 9 447 - 53 2004年09月 

  Percutaneous balloon angioplasty for subclavian stenosis achieves satisfactory procedural success rates except for total occlusion. Seven lesions in six consecutive patients who underwent stenting for subclavian total occlusion were reviewed to evaluate the feasibility and efficacy of endovascular stenting. Six lesions were treated using Palmaz stents, and one with the combination of a Palmaz and a SMART stent. Procedural success (residual stenosis < 30%) was achieved for all lesions. The only neurological complication was an embolism in a branch of the posterior cerebral artery, which resulted in homonymous hemianopsia. Follow-up angiography over 6 months after the stenting for five lesions found one in-stent re-occlusion and one ostial restenosis due to elastic recoil. No patient had any new or recurrent symptoms except for recurrent upper limb ischemia due to the case of in-stent re-occlusion during the clinical follow-up period of 1 to 52 months (mean 16.6 months). This complication was resolved by a second treatment. Our limited experience suggests that stenting can redilate even cases of angiographical total occlusion of the proximal segment of the subclavian artery.
• Use of a large angioplasty balloon for predilation is a risk factor for embolic complications in protected carotid stenting.

  Akiyo Sadato; Tetsu Satow; Akira Ishii; Takeshi Ohta; Nobuo Hashimoto

  Neurologia medico-chirurgica 44 7 337 - 42 2004年07月 

  Periprocedural neurological complications (PNCs) after carotid stenting were retrospectively analyzed to determine the risk factors with the use of various protective devices. Forty-three lesions in 40 patients were treated by carotid stenting with distal balloon protection for nearly all postdilation procedures and some predilation procedures. The following variables were statistically analyzed for association with PNCs: diameter of the angioplasty balloon used for predilation, use of a distal protection balloon during predilation, use of a protection balloon during postdilation, lesion-bifurcation distance, length of the lesion, age, clinical presentation of the lesion (symptomatic or asymptomatic), and hypercholesterolemia. PNCs occurred in five patients, four with minor deficits and one with major deficits. Univariate analysis showed large diameter of the predilation angioplasty balloon (p = 0.0026), use of a protection balloon during predilation (p = 0.0075), lesion length (p = 0.0003), and lesion-bifurcation distance (p = 0.0006) were significantly associated with PNCs. Multivariate analysis of these four variables showed that use of a large angioplasty balloon for predilation was the only independent predictor (p = 0.004, odds ratio 34.00) for the occurrence of PNCs. Use of a large angioplasty balloon for predilation carries the risk of periprocedural embolic complications. Therefore, even when a protection device is used, predilation should be performed with a small balloon.
• Diagnosis and Treatment of Spinal Arteriovenous Malformation

  Susumu MIYAMOTO; Hiroharu KATAOKA; Tetsu SATOW

  Surgery for Cerebral Stroke 32 1 1 - 6 Japanese Society on Surgery for Cerebral Stroke 2004年 [査読有り]
   

  Spinal arteriovenous malformation (spinal AVM) is a rare but clinically important disease in that it presents with progressive, somewhat stepwise worsening myelopathy, and its outcome of natural course is very poor. Classification of spinal AVM based on angiographical features has been very difficult to understand, and we propose here a comprehensive one based upon the sites of A-V shunts. For diagnostic purposes, MRI gives us not only the location of AVM but also the existence of venous congestion in the spinal cord itself. But selective spinal angiography still remains the gold standard for confirming the shunt points and planning the strategy of treatment. Both surgical and endovascular interventions are available for its treatment, and we detail all the surgical treatment procedures. The lateral oblique position reduces the risk of venous hypertension during surgery and is also comfortable for the operator. Using microdoppler monitoring with meticulous temporary clipping is somewhat laborious but the best method for understanding the complex vasculature as well as accurately implementing treatment. What is most essential is that the total extirpation of abnormal A-V shunts be realized for this disease to achieve total cure. The treatment strategy should be based on this point, and palliative therapy, which would produce a more complicated condition afterwards, should be avoided.
• 無症候性頸部・脳主幹動脈狭窄病変

  Tetsu Satow; Nobuo Hashimoto

  脳と神経 56 1 21 - 8 2004年01月
• Strategy for the proper and safe treatment of cerebral aneurysm

  Susumu Miyamoto; Keisuke Yamada; Ken-Ichiro Kikuta; Hiroharu Kataoka; Tetsu Satow; Nobuo Hashimoto

  Japanese Journal of Neurosurgery 12 6 412 - 418 2003年06月 [査読有り]
   

  There are 3 therapeutic methods for cerebral aneurysms: clipping, endovascular coil embolization, and parent artery occlusion with or without bypass procedures. For lesions such as giant or partially thrombosed aneurysms, which are difficult to treat by a single therapeutic method, the combined use of the 3 methods is required. The therapeutic design for cerebral aneurysms should be decided by the features of the lesion, not by the concept or speciality of the surgeons. In order to devise proper strategy for treating cerebral aneurysms, we should include the clipping technique, the endovascular intervention technique, and the microsurgical anastomosis technique. To perform aneurysmal clipping properly and safely during the operation, surgeons should know the mechanics of the aneurysmal clips. Since the moment of a force is calculated as force by the length of arm, closing force of aneurysmal clips varies by the distance from the blade tips. Width of the opened blade tips are also different between clip brands. Finally, configurations of the clip blade are also different between clip brands. Surgeons should select a proper aneurysmal clip which is suitable for the lesion. Proper therapeutic strategy and knowledge of equipment are key to success in the treatment of cerebral aneurysms.
• Large vertebral arteriovenous fistula treated with stent-grafts--case report.

  Akiyo Sadato; Tetsu Satow; Akira Ishii; Motohiro Takayama; Nobuo Hashimoto

  Neurologia medico-chirurgica 43 5 250 - 4 2003年05月 

  A 24-year-old woman presented with neck bruit and thrill. Neurological examination revealed no focal abnormality. Angiography and magnetic resonance imaging showed an arteriovenous fistula (AVF) at the C4-5 levels of the right vertebral artery (VA). The fistula had a single orifice that drained into the epidural veins via the C4-5 intervertebral foramen. A stent-graft was made of a 3.9 cm balloon-expandable stent and an expandable polytetrafluoroethylene graft sutured outside the stent. The stent-graft was advanced through the femoral artery up to the VA but did not pass far enough distally to seal the entire fistula because of the high friction between the bulky device and the small vessel. Another 2 cm stent-graft was delivered and successfully positioned across the fistula. The AVF completely disappeared and the right VA was well preserved. Follow-up angiography at 3 weeks and 5 months after the treatment showed no fistula and no stenosis inside the stent-grafts. Stent-grafts are useful to treat AVF with a large orifice. The stent-graft is a promising technology to treat neurovascular diseases, although improvement is required for use in smaller vessels.
• The Basic Helix-Loop-Helix Genehesr2Promotes Gliogenesis in Mouse Retina

  Tetsu Satow; Soo-Kyung Bae; Tomoyuki Inoue; Chihiro Inoue; Goichi Miyoshi; Koichi Tomita; Yasumasa Bessho; Nobuo Hashimoto; Ryoichiro Kageyama

  The Journal of Neuroscience 21 4 1265 - 1273 2001年02月 

  Members of a subclass ofhairy/Enhancer of split[E(spl)] homologs, calledhesrgenes, are structurally related to another subclass ofhairy/E(spl)homologs,Hesgenes, which play an important role in neural development. To characterize the roles ofhesrgenes in neural development, we used the retina as a model system.In situhybridization analysis indicated that allhesrgenes are expressed in the developing retina, but onlyhesr2expression is associated spatially with gliogenesis. Each member was then misexpressed with retrovirus in the retinal explant cultures prepared from mouse embryos or neonates, which well mimicin vivoretinal development. Interestingly,hesr2but nothesr1orhesr3promoted gliogenesis while inhibiting rod genesis without affecting cell proliferation or death, suggesting that the cells that normally differentiate into rods adopted the glial fate by misexpression ofhesr2. The gliogenic activity ofhesr2was more profound when it was misexpressed postnatally than prenatally. In addition, double mutation of the neuronal determination genesMash1andMath3, which increases Müller glia at the expense of bipolar cells, upregulatedhesr2expression. These results indicate that, among structurally relatedhesrgenes, onlyhesr2promotes glial versus neuronal cell fate specification in the retina and that antagonistic regulation betweenhesr2andMash1–Math3may determine the ratios of neurons and glia.

書籍

• くも膜下出血のすべて : 再開通療法の新時代

  佐藤 徹 (担当:分担執筆範囲:VA disssectionにおけるshort segmentでのtight packingのコツ)診断と治療社 2019年07月 ISBN: 9784787823786 xi, 189p
• アクセスのすべて : 脳血管内治療成功の鍵

  佐藤 徹 (担当:分担執筆範囲:内頚静脈直接穿刺による頭蓋内静脈病変へのアプローチ)診断と治療社 2018年03月 ISBN: 9784787823236 xiv, 221p

講演・口頭発表等

• Safety and efficacy of a novel, microporous covered stent system for treating intracranial aneurysms  [招待講演]

  Tetsu Satow

  22nd Oriental Conference of Interventional Neuroradiology (OCIN 2022) 2022年12月 シンポジウム・ワークショップパネル（指名）
• 脳動脈瘤治療用多孔化カバードステントの有用性と安全性、今後の展望  [通常講演]

  佐藤 徹; 坂井信幸; 大石英則; 石井 暁; 髙橋 淳; 片岡大治

  第38回NPO法人日本脳神経血管内治療学会総会 2022年11月 シンポジウム・ワークショップパネル（公募）
• CAS as the first-line therapy for ICS -what to learn from experiences in Japan-  [招待講演]

  Tetsu Satow

  16th congress of World Federation of Therapeutic Interventional Neuroradiology (WFITN) 2022年08月 シンポジウム・ワークショップパネル（指名）
• 脳動脈瘤治療用多孔化カバードステント;医師主導治験結果からみる有用性と安全性  [招待講演]

  佐藤 徹; 坂井信幸; 大石英則; 石井 暁; 髙橋 淳; 片岡大治

  第28回日本血管内治療学会 2022年06月 シンポジウム・ワークショップパネル（指名）
• 「知識、技術、責任」を軸とした脳血管内治療医の教育  [招待講演]

  佐藤 徹

  第42回日本脳神経外科コングレス総会 2022年05月 公開講演，セミナー，チュートリアル，講習，講義等
• 椎骨動脈部分血栓化動脈瘤に対する血管内治療：母血管閉塞か温存か  [通常講演]

  佐藤 徹; 角真佐武; 西脇崇裕貴; 濱野栄佳; 下永皓司; 櫛 裕史; 永野祐志; 池堂太一; 太田剛史; 飯原弘二; 髙橋 淳; 片岡大治

  第31回脳神経外科手術と機器学会総会 2022年04月 シンポジウム・ワークショップパネル（公募）
• AVM 術前塞栓術でのpartial nidal penetration の有用性と安全性  [通常講演]

  佐藤 徹; 濱野栄佳; 角真佐武; 池堂太一; 下永皓司; 櫛 裕史; 太田剛史; 高橋 淳; 飯原弘二; 片岡大治

  第37回NPO法人日本脳神経血管内治療学会総会 2021年11月 シンポジウム・ワークショップパネル（公募）
• 「知識・技術・責任」を軸とした脳血管内治療医教育システムの有用性  [通常講演]

  佐藤 徹; 濱野栄佳; 角真佐武; 下永皓司; 池堂太一; 櫛 裕史; 永野祐志; 西脇崇裕貴; 手賀丈太; 太田剛史; 飯原弘二; 片岡大治

  第37回NPO法人日本脳神経血管内治療学会総会 2021年11月 シンポジウム・ワークショップパネル（公募）
• 横-S状静脈洞部硬膜動静脈瘻におけるTAE/TVE併用の有用性と安全性  [通常講演]

  佐藤 徹; 原 健司; 太田剛史; 濱野栄佳; 橋村直樹; 角真佐武; 池堂太一; 櫛 裕史; 内田 充; 西脇崇裕貴; 飯原弘二; 片岡大治

  第36回NPO法人日本脳神経血管内治療学会総会 2020年11月 シンポジウム・ワークショップパネル（公募）
• 若手脳血管内治療医に伝承すべきprinciple: 知識、技術、そして責任  [通常講演]

  佐藤 徹; 原 健司; 太田剛史; 濱野栄佳; 橋村直樹; 角真佐武; 池堂太一; 櫛 裕史; 内田 充; 西脇崇裕貴; 飯原弘二; 片岡大治

  第36回NPO法人日本脳神経血管内治療学会総会 2020年11月 シンポジウム・ワークショップパネル（公募）

MISC

• High Systolic Blood Pressure Variability After Successful Reperfusion Therapy in Acute Ischemic Stroke Predicts Unfavorable Outcomes

  Satoshi Hosoki; Kaori Miwa; Takeshi Yoshimoto; Kanta Tanaka; Hajime Ikenouchi; Tadataka Mizoguchi; Shunsuke Kimura; Tetsuya Chiba; Tetsu Satow; Jun C. Takahashi; Kazunori Toyoda; Masafumi Ihara; Masatoshi Koga STROKE 51 2020年02月
• Correlation Between Collateral Circulations, Cerebral Metabolisms and Posterior Cerebral Artery Stenoses or Occlusions in Moyamoya Disease.

  Seiichiro Eguchi; Jyoji Nakagawara; Sei Sugata; Daisuke Maruyama; Eika Hamano; Yoji Orita; Tetsu Satow; Hiroharu Kataoka; Jun Takahashi STROKE 47 2016年02月
• Selection and Outcomes of Multimodality Interventional Treatment for Unruptured Arteriovenous Malformations in a Single Institution

  Daisuke Maruyama; Hisae Mori; Tetsu Satow; Hiroharu Kataoka; Sei Sugata; Eika Hamano; Yoji Orita; Seiichiro Eguchi; Jun Takahashi STROKE 47 2016年02月
• Periprocedural Elevation of Von Willebrand Factor is Associated With Thromboembolic Events in Coil Embolization of Unruptured Intracranial Aneurysms Under Dual Antiplatelet Therapy

  Minoru Ideguchi; Tetsu Satow; Shigeki Takada; Sei Sugata; Daizo Ishii; Daisuke Maruyama; Eika Hamano; Masataka Hayashi; Hideki Kanamaru; Hiroharu Kataoka; Koji Iihara; Jun Takahashi STROKE 46 2015年02月
• Hemorrhagic Risk of Cerebral Arteriovenous Malformations after Gamma Knife Surgery

  Hisae Mori; Koji Iihara; Hiroharu Kataoka; Tetsu Satow; Ken-ichi Morita CEREBROVASCULAR DISEASES 34 37 -37 2012年

その他のリンク

researchmap

https://researchmap.jp/tedsatow1970