• Journal of Korean Neurosurgical Society
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• v.58 no.5
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• pp.419-425
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• 2015

Objective : Acute vertebrobasilar artery occlusion (AVBAO) is a devastating disease with a high mortality rate. One of the most important factors affecting favorable clinical outcome is early recanalization. Mechanical thrombectomy is an emerging treatment strategy for achieving a high recanalization rates. However, thrombectomy alone can be insufficient to complete recanalization, especially for acute stroke involving large artery atheromatous disease. The purpose of this study is to investigate the safety and efficacy of mechanical thrombectomy in AVBAO. Methods : Fourteen consecutive patients with AVBAO were treated with mechanical thrombectomy. Additional multimodal treatments were intra-arterial (IA) thrombolysis, balloon angioplasty, or permanent stent placement. Recanalization by thrombectomy alone and multimodal treatments were assessed by the Thrombolysis in Cerebral Infarction (TICI) score. Clinical outcome was determined using the National Institutes of Health Stroke Scale (NIHSS) at 7 days and the modified Rankin Scale (mRS) at 3 months. Results : Thrombectomy alone and multimodal treatments were performed in 10 patients (71.4%) and 4 patients (28.6%), respectively. Successful recanalization (TICI 2b-3) was achieved in 11 (78.6%). Among these 11 patients, 3 (27.3%) underwent multimodal treatment due to underlying atherosclerotic stenosis. Ten (71.4%) of the 14 showed NIHSS score improvement of >10. Overall mortality was 3 (21.4%) of 14. Conclusion : We suggest that mechanical thrombectomy is safe and effective for improving recanalization rates in AVBAO, with low complication rates. Also, in carefully selected patients after the failure of recanalization by thrombectomy alone, additional multimodal treatment such as IA thrombolysis, balloons, or stents can be needed to achieve successful recanalization.

• Journal of Korean Neurosurgical Society
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• v.65 no.1
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• pp.22-29
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• 2022

Objective : Despite many advancements in endovascular treatment, the benefits of mechanical thrombectomy (MT) in patients with large infarctions remain uncertain due to hemorrhagic complications. Therefore, we aimed to investigate the efficacy and safety of recanalization via MT within 6 hours after stroke in patients with large cerebral infarction volumes (>70 mL). Methods : We retrospectively reviewed the medical data of 30 patients with large lesions on initial diffusion-weighted imaging (>70 mL) who underwent MT at our institution within 6 hours after stroke onset. Baseline data, recanalization rate, and 3-month clinical outcomes were analyzed. Successful recanalization was defined as a modified treatment in cerebral ischemia score of 2b or 3. Results : The recanalization rate was 63.3%, and symptomatic intracerebral hemorrhage occurred in six patients (20%). The proportion of patients with modified Rankin Scale (mRS) scores of 0-3 was significantly higher in the recanalization group than in the non-recanalization group (47.4% vs. 9.1%, p=0.049). The mortality rate was higher in the non-recanalization group, this difference was not significant (15.8% vs. 36.4%, p=0.372). In the analysis of 3-month clinical outcomes, only successful recanalization was significantly associated with mRS scores of 0-3 (90% vs. 50%, p=0.049). The odds ratio of recanalization for favorable outcomes (mRS 0-3) was 9.00 (95% confidence interval, 0.95-84.90; p=0.055). Conclusion : Despite the risk of symptomatic intracerebral hemorrhage, successful recanalization via MT 6 hours after stroke may improve clinical outcomes in patients with large vessel occlusion.

• Journal of Korean Neurosurgical Society
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• v.53 no.2
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• pp.77-82
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• 2013

Objective : Sudden major cerebral artery occlusion often resists recanalization with currently available techniques or can results in massive symptomatic intracranial hemorrhage (sICH) after thrombolytic therapy. The purpose of this study was to examine mechanical recanalization with a retrievable self-expanding stent and balloon in acute intracranial artery occlusions. Methods : Twenty-eight consecutive patients with acute intracranial artery occlusions were treated with a Solitaire retrievable stent. Balloon angioplasty was added if successful recanalization was not achieved after stent retrieval. The angiographic outcome was assessed by Thrombolysis in Cerebral Infarction (TICI) and the clinical outcomes were assessed by the National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin Scale (mRS). Results : At baseline, mean age was 69.4 years and mean initial NIHSS score was 12.5. A recanalization to TICI 2 or 3 was achieved in 24 patients (85%) after stent retrieval. Successful recanalization was achieved after additional balloon angioplasty in 4 patients. At 90-day follow-up, 24 patients (85%) had a NIHSS improvement of ${\geq}4$ and 17 patients (60%) had a good outcome (mRS ${\leq}2$). Although there was sICH, there was one death associated with the procedure. Conclusion : Mechanical thromboembolectomy with a retrievable stent followed by additional balloon angioplasty is a safe and effective first-line therapy for acute intracranial artery occlusions especially in case of unsuccessful recanalization after stent thrombectomy.

• Journal of Korean Neurosurgical Society
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• v.58 no.3
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• pp.192-196
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• 2015

Objective : The aim of this study is to investigate good prognostic factors for an acute occlusion of a major cerebral artery using mechanical thrombectomy. Methods : Between January 2013 to December 2014, 37 consecutive patients with acute occlusion of a major cerebral artery treated by mechanical thrombectomy with stent retrievers were conducted. We analyzed clinical and angiographic factors retrospectively. The collateral flow and the result of recanalization were sorted by grading systems. Outcome was assessed by National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) at 90 days. We compared the various parameters between good and poor angiographic and clinical results. Results : Twenty seven patients demonstrated good recanalization [Thrombolysis in Cerebral Infarction (TICI) 2b or 3] after thrombectomy. At the 90-day follow up, 19 patients had good (mRS, 0-2), 14 had moderate (3-4) and four had poor outcomes (5-6). The mRS of older patients (${\geq}75years$) were poor than younger patients. Early recanalization, high Thrombolysis in Myocardial Infarction risk score, and low baseline NIHSS were closely related to 90-day mRS, whereas high TICI was related to both mRS and the decrease in the NIHSS. Conclusion : NIHSS decreased markedly only when recanalization was successful. A good mRS was related to low initial NIHSS, good collateral, and early successful recanalization.

• Journal of Korean Neurosurgical Society
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• v.45 no.6
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• pp.360-368
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• 2009

Objective : The objectives of this study were to analyze the recanalization rates and outcomes of multimodal therapy that consisted of sequential intravenous (IV)/intra-arterial (IA) thrombolysis, mechanical thrombolysis including mechanical clot disruption using microcatheters and microwires, balloon angioplasty, and stenting for acute ischemic stroke, and to evaluate the prognostic factors related to the outcome. Methods : Fifty patients who were admitted to the hospital within 8 hours from ischemic symptom onset were retrospectively analyzed. Initial IV thrombolysis and subsequent cerebral angiography were performed in all patients. If successful recanalization was not achieved by IV thrombolysis, additional IA thrombolysis with mechanical thrombolysis, including balloon angioplasty and stenting, were performed. The outcomes were assessed by the National Institute of Health Stroke Scale (NIHSS) change and modified Rankin scale (mRS) and prognostic factors were analyzed. Results : Successful recanalization was achieved in 42 (84%) of 50 patients, which consisted of 8 patients after IV thrombolysis, 19 patients after IA thrombolysis with mechanical clot disruption, and 15 patients after balloon angioplasty or stenting. Symptomatic hemorrhage occurred in 4 (8%) patients. Good outcomes were achieved in 76% and 70% of patients upon discharge, and 93% and 84% of patients after 3 months according to the NIHSS change and mRS. The initial clinical status, recanalization achievement, and presence of symptomatic hemorrhage were statistically related to the outcomes. Conclusion : Multimodal therapy may be an effective and safe treatment modality for acute ischemic stroke. Balloon angioplasty and stenting is effective for acute thrombolysis, and produce higher recanalization rates with better outcomes.

• Journal of Korean Neurosurgical Society
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• v.64 no.5
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• pp.732-739
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• 2021

Objective : Early successful reperfusion is associated with favorable outcomes in acute ischemic stroke (AIS). The purpose of this study was to achieve successful recanalization by a combined mechanical thrombectomy technique, the Aspiration-Retriever Technique for Stroke (ARTS), which is composed of a flexible large lumen distal access catheter and a retrievable stent as the first-line strategy of mechanical thrombectomy. Methods : We retrospectively reviewed 62 patients with AIS who underwent mechanical thrombectomy from 2018 to 2019 at our institute by a senior neurointerventionalist. Among them, patients who were treated using the ARTS technique with the soft torqueable catheter optimized for intracranial access (SOFIA^®; MicroVention-Terumo, Tustin, CA, USA) as the first-line treatment were included. Patients who had tandem occlusions or underlying intracranial artery stenosis were excluded. The angiographic and clinical outcomes were evaluated. The angiographic outcome was analyzed by the rate of successful recanalization, defined as a Thrombolysis in Cerebral Infarction score of 2b or 3 at the end of all procedures and the rate of successfully achieving the first pass effect (FPE), defined as complete recanalization with a single pass of the device. The clinical outcomes included the National Institutes of Health Stroke Scale (NIHSS) score, modified Rankin Scale (mRS), and mortality. Results : A total of 27 patients (mean age, 59.3 years) fulfilled the inclusion criteria. The successful recanalization rate was 96% (n=26) while the FPE rate was 41% (n=11). The mean post-procedural NIHSS change was -3.0. Thirteen patients (48%) showed good clinical outcomes after thrombectomy with the ARTS technique (mRS at 90 days ≤2). Postoperative complications occurred in seven of 25 patients : hemorrhagic transformation in six patients (22%) and distal embolization in one patient (4%). Mortality was 15% (n=4). Conclusion : Although the clinical outcomes using the ARTS technique with a flexible large lumen distal access catheter performed as the frontline thrombectomy in patients with AIS were not significantly superior than those of other studies, this study showed a high rate of successful endovascular recanalization which was comparable to that of other studies. Therefore, ARTS using the SOFIA^® catheter can be considered as the first choice of treatment for AIS due to large vessel occlusion.

• Journal of Korean Neurosurgical Society
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• v.64 no.1
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• pp.60-68
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• 2021

Objective : Until recently, the transfemoral approach (TFA) was used as the primary method of arterial approach in acute ischemic stroke (AIS). However, TFA resulted in longer reperfusion times and worse outcomes in the mechanical thrombectomy (MT) of patients with complex aortic arches and significant carotid tortuosity. We found that the transradial approach (TRA) is a more favorable alternative approach for MT in such cases. Methods : We performed a retrospective review of our institutional database to identify 202 patients who underwent MT for AIS between February 2015 and December 2019. Patient characteristics, cause of TFA failure, procedure time, intra-procedural complications, and outcomes were recorded. Results : Eleven (5.4%) of 202 patients, who underwent MT for AIS, crossed over to TRA for recanalization, and eight (72%) of 11 achieved successful recanalization (≥modified Treatment in Cerebral Infarction 2b). The mean age (mean±standard deviation [median]) was 82.3±6.6 (76) years, and five of the 11 patients were male. The last seen normal to puncture time was 467.9±264.72 (264) minutes; baseline National Institutes of Health Stroke Scale score was 28.9±14.5 (16). Six (55%) of the 11 patients had right vertebrobasilar occlusions, and the remaining five (45%) had anterior circulation occlusive disease. The time from groin puncture to final recanalization time (overall procedural time) was 78.0±20.1 (62) minutes. The mean crossover time from TFA to TRA was 45.2±10.5 (41) minutes. The mean time from radial puncture to final recanalization was 33.8±10.5 (28) minutes. Distal thrombus migration events in previously unaffected territories occurred in 3/8 patients (37%). At 90 days, three patients (28%) had a favorable clinical outcome. Conclusion : Although rare, failure of TFA has been known to occur during MT for AIS. Our results demonstrate that TRA may be an alternative option for AIS intervention for select patients with subsequent timely revascularization. However, the incidence of distal thrombus migration was high, and the first puncture to reperfusion time was prolonged because of the time taken for the crossover to TRA after failure of TFA. This study provides some evidence that the TRA may be a viable alternative option to the TFA for MT of AIS.

• Journal of Korean Neurosurgical Society
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• v.62 no.4
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• pp.389-397
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• 2019

Objective : Mechanical thrombectomies with balloon-guide catheters (BGC) are thought to improve successful recanalization rates and to decrease the incidence of distal emboli compared to thrombectomies without BGC. We aimed to assess the effects of BGC on the outcomes of mechanical thrombectomy in acute ischemic strokes. Methods : Studies from PubMed, EMBASE, and the Cochrane library database from January 2010 to February 2018 were reviewed. Random effect model for meta-analysis was used. Analyses such as meta-regression and the "trim-and-fill" method were additionally carried out. Results : A total of seven articles involving 2223 patients were analyzed. Mechanical thrombectomy with BGC was associated with higher rates of successful recanalization (odds ratio [OR], 1.632; 95% confidence interval [CI], 1.293-2.059). BGC did not significantly decrease distal emboli, both before (OR, 0.404; 95% CI, 0.108-1.505) and after correcting for bias (adjusted OR, 1.165; 95% CI, 0.310-4.382). Good outcomes were observed more frequently in the BGC group (OR, 1.886; 95% CI, 1.564-2.273). Symptomatic intracranial hemorrhage and mortality did not differ significantly with BGC use. Conclusion : Our meta-analysis demonstrates that BGC enhance recanalization rates. However, BGC use did not decrease distal emboli after mechanical thrombectomies. This should be interpreted with caution due to possible publication bias and heterogeneity. Additional meta-analyses based on individual patient data are needed to clarify the role of BGC in mechanical thrombectomies.

• Journal of Korean Neurosurgical Society
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• v.50 no.4
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• pp.311-316
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• 2011

Objective : Stroke is the third leading cause of death in the Republic of Korea. Time is the most important factor in hyperacute stroke. Yet, there had been no protocol for mechanical thrombolysis. We have treated patients with hyperacute stroke by mechanical thrombolysis for 3 years. In current study, we analyzed the outcome of mechanical thrombolysis. Methods : From March 2008 to February 2011, 36 patients were treated with mechanical thrombolysis. Initially we treated the patients by aggressive mechanical clot disruption (AMCD) who were admitted within 6 hours after the symptom onset. If revascularization was not achieved, balloon angioplasty was performed, followed by stenting or temporary endovascular bypass was performed. The result in 15 cases was not so successful. Since then, we started using the thromboaspiration method as the first line treatment of the mechanical thrombolysis. Results : After using the thromboaspiration, we had better results in recanalization rate, modified Rankin Score (mRS) and reperfusion injury compared to AMCD. The recanalization rate was 80.85%, mRS is 2.85, and there was only 0.09% hemorrhagic formation. Conclusion : Even though thromboaspiration is not statistically significant due to the limited numbers of patients enrolled in this study, we think it is a good way in mechanical thronbolysis for hyperacute stroke.

• Korean Journal of Radiology
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• v.24 no.2
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• pp.145-154
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• 2023

Objective: We aimed to evaluate the efficacy of EmboTrap II in terms of first-pass recanalization and to determine whether it could yield favorable outcomes. Materials and Methods: In this multicenter, prospective study, we consecutively enrolled patients who underwent mechanical thrombectomy using EmboTrap II as a front-line device. The primary outcome was the first pass effect (FPE) rate defined by modified Thrombolysis In Cerebral Infarction (mTICI) grade 2c or 3 by the first pass of EmboTrap II. In addition, modified FPE (mFPE; mTICI grade 2b-3 by the first pass of EmboTrap II), successful recanalization (final mTICI grade 2b-3), and clinical outcomes were assessed. We also analyzed the effect of FPE on a modified Rankin Scale (mRS) score of 0-2 at 3 months. Results: Two hundred-ten patients (mean age ± standard deviation, 73.3 ± 11.4 years; male, 55.7%) were included. Ninety-nine patients (47.1%) had FPE, and mFPE was achieved in 150 (71.4%) patients. Successful recanalization was achieved in 191 (91.0%) patients. Among them, 164 (85.9%) patients underwent successful recanalization by exclusively using EmboTrap II. The time from groin puncture to FPE was 25.0 minutes (interquartile range, 17.0-35.0 minutes). Procedure-related complications were observed in seven (3.3%) patients. Symptomatic intracranial hemorrhage developed in 14 (6.7%) patients. One hundred twenty-three (58.9% of 209 completely followed) patients had an mRS score of 0-2. Sixteen (7.7% of 209) patients died during the follow-up period. Patients who had successful recanalization with FPE were four times more likely to have an mRS score of 0-2 than those who had successful recanalization without FPE (adjusted odds ratio, 4.13; 95% confidence interval, 1.59-10.8; p = 0.004). Conclusion: Mechanical thrombectomy using the front-line EmboTrap II is effective and safe. In particular, FPE rates were high. Achieving FPE was important for an mRS score of 0-2, even in patients with successful recanalization.