Balloon guide catheter improves revascularization and clinical outcomes with the Solitaire device: analysis of the North American Solitaire Acute Stroke Registry

Usefulness of combination usage of balloon guide catheter with contact aspiration thrombectomy

BACKGROUND

Angiographic outcomes of contact aspiration thrombectomy (CAT), a frontline thrombectomy strategy, can vary depending on balloon guide catheter (BGC) usage, stroke etiology, and occlusion location. The purpose of this study was to analyze conditional outcomes of CAT to determine which result in maximum angiographic benefits.

METHODS

Patients who received CAT for anterior circulation occlusive stroke between January 2017 and December 2018 were included. Angiographic and clinical outcomes were compared relative to BGC use, stroke etiology, and occlusion location. Multivariable analyses for first-pass reperfusion (FPR) and favorable clinical outcome were performed.

RESULTS

Of 160 included patients, the rates of FPR, successful reperfusion after CAT, final successful reperfusion, and favorable clinical outcome were 43.1%, 58.1%, 81.9%, and 60.6%, respectively. BGC use was associated with a higher rate of FPR, successful reperfusion after CAT, a lower rate of distal embolization, and faster reperfusion. Based on subgroup analysis, BGC usage in ICA, MCA M1 occlusion, and cardioembolism were associated with higher FPR, successful reperfusion after CAT, and lower distal embolization. Faster reperfusion was achieved in ICA occlusions and cardioembolisms. BGC usage was an independent predictor of FPR. Favorable clinical outcome was associated with male gender, low initial NIHSS score, fast onset to reperfusion, and FPR.

CONCLUSIONS

In CAT, BGC usage was associated with better angiographic outcomes, including higher FPR, successful reperfusion after CAT, prevention of distal embolization, and faster reperfusion, especially in proximal occlusions and cardioembolisms. These conditions may play a role in maximizing the benefits of CAT.

Stent-retriever alone vs. aspiration and stent-retriever combination in large vessel occlusion stroke: A matched analysis

BACKGROUND

Three randomized clinical trials have reported similar safety and efficacy for contact aspiration and stent-retriever thrombectomy.

AIM

We aimed to determine whether the combined technique (stent-retriever + contact aspiration) was superior to stent-retriever alone as first-line thrombectomy strategy in a patient cohort where balloon guide catheter was universally used.

METHODS

A prospectively maintained mechanical thrombectomy database from January 2018 to December 2019 was reviewed. Patients were included if they had anterior circulation proximal occlusion ischemic stroke (intracranial ICA or MCA-M1/M2 segments) and underwent stent-retriever alone thrombectomy or stent-retriever + contact aspiration as first-line therapy. The primary outcome was the first-pass effect (mTICI2c-3). Secondary outcomes included modified first-pass effect (mTICI2b-3), successful reperfusion (mTICI2b-3) prior to and after any rescue strategy, and 90-day functional independence (mRS ≤ 2). Safety outcomes included rate of parenchymal hematoma type-2 and 90-day mortality. Sensitivity analyses were performed after dividing the overall cohort according to first-line modality into two matched groups.

RESULTS

A total of 420 patients were included in the analysis (mean age 64.4 years; median baseline NIHSS 16 (11-21)). As compared to first-line stent-retriever alone, first-line stent-retriever + contact aspiration resulted in similar rates of first-pass effect (53% vs. 51%, adjusted odds ratio (aOR) 1.122, 95%CI (0.745-1.691), p = 0.58), modified first-pass effect (63% vs. 60.4%, aOR1.250, 95%CI (0.782-2.00), p = 0.35), final successful reperfusion (97.6% vs. 98%, p = 0.75), and higher chances of successful reperfusion prior to any rescue strategy (81.8% vs. 72.5%, aOR 2.033, 95%CI (1.209-3.419), p = 0.007). Functional outcome and safety measures were comparable between both groups. Likewise, the matched analysis (148 patient-pairs) demonstrated comparable results for all clinical and angiographic outcomes except for significantly higher rates of successful reperfusion prior to any rescue strategies with the first-line stent-retriever + contact aspiration treatment (81.8% vs. 73.6%, aOR 1.881, 95%CI (1.039-3.405), p = 0.037).

CONCLUSIONS

Our findings reinforce the findings of ASTER-2 trial in that the first-line thrombectomy with a combined technique did not result in increased rates of first-pass reperfusion or better clinical outcomes. However, the addition of contact aspiration after initial stent-retriever failure might be beneficial in achieving earlier reperfusion.

Walrus large bore guide catheter impact on recanalization first pass effect and outcomes: the WICkED study

BACKGROUND

The use of a balloon-guide catheter (BGC) in acute stroke treatment has been widely adopted after demonstrating optimized procedure metrics and outcomes. Initial technical constraints of previous devices included catheter stiffness and smaller inner diameters. We aim to evaluate the performance and safety of the Walrus BGC, a variable stiffness catheter with a large bore 0.087 inch inner diameter (ID), via the the WICkED study (Walrus Large Bore guide Catheter Impact on reCanalization first pass Effect anD outcomes).

METHODS

This is a retrospective, site adjudicated, multicenter study on consecutive patients with large vessel occlusion treated with the Walrus BGC. Baseline characteristics, procedural outcomes and functional outcomes were analyzed.

RESULTS

A total of 338 patients met the inclusion criteria. The Walrus was successfully tracked into distal vasculature and allowed therapeutic device delivery in all but 3 cases (0.9%). Large aspiration catheters ≥0.070 inch ID were used in 71.9% of cases. Stent retriever thrombectomy was used as the first-line modality in 59.2% and thromboaspiration in 40.8% of cases. The successful recanalization rate (modified treatment in cerebral ischemia (mTICI) 2b/3) was 94.4%, with 64.8% of the patients achieving mTICI 2b/3 after the first pass. The Walrus-related adverse event rate was 0.6%, corresponding to two vessel dissections. Functional independence was 50% (126/252) and mortality 25% (63/252). Unfavorable outcomes were more likely in older patients, who had unsuccessful reperfusion, longer procedure times, and a higher mean number of passes.

CONCLUSION

In acute ischemic stroke patients presenting with large vessel occlusion, the Walrus BGC demonstrated excellent navigability and safety profile, allowed the accommodation of leading large bore aspiration catheters, and demonstrated high vessel recanalization rates.

Impact of aspiration catheter size on first-pass effect in the combined use of contact aspiration and stent retriever technique

Background and purpose

The first-pass effect (FPE), defined as a first-pass Expanded Treatment in Cerebral Ischaemia (eTICI) 2c/3 reperfusion, has emerged as a key metric of efficacy in mechanical thrombectomy (MT) for acute ischaemic stroke. The proximal balloon occlusion together with direct thrombus aspiration during stent retriever thrombectomy (PROTECT)-PLUS technique consists in the use of a balloon guide catheter and a combined MT approach involving contact aspiration and a stent retriever. The aim of this study is to assess the effectiveness and safety of the PROTECT-PLUS technique using distal aspiration catheters (DACs) with different inner diameters by comparing the large-bore DAC Catalyst 7 versus the use of medium-bore DACs.

Methods

Retrospective analysis of a prospectively maintained database of patients treated with PROTECT-PLUS using Catalyst 7, Catalyst 6 or Catalyst 5 with an occlusion of either the terminal carotid artery or the M1 or M2 segments of the middle cerebral artery from 2018 to 2020 in two comprehensive stroke centres. Baseline characteristics and procedural, safety and clinical outcomes were compared between groups. Multivariable logistic regression analysis was performed in order to find independent predictors of FPE.

Results

We identified 238 consecutive patients treated with PROTECT-PLUS as front-line approach using Catalyst 7 (n=86), Catalyst 6 (n=78) and Catalyst 5 (n=76). The rate of FPE was higher with Catalyst 7 (54%) than Catalyst 6 (33%, p=0.009) and Catalyst 5 (32%, p=0.005), in addition to higher final eTICI 2c/3 reperfusion rates, shorter procedural times, lower need of rescue therapy and fewer procedure-related complications. After multivariable analysis the sole independent factor associated to FPE was the use of Catalyst 7 (OR 2.34; 95% CI 1.19 to 4.58; p=0.014).

Conclusion

Further development of combined MT by incorporating larger-bore aspiration catheters is associated with higher reperfusion rates, shorter procedure times, and lower need of rescue therapy while reducing the complication rates.

Factors Contributing to an Efficacious Endovascular Treatment for Acute Ischemic Stroke in Asian Population

Although randomized control trials about endovascular treatment (EVT) of emergent large vessel occlusion (LVO) have demonstrated the success of mechanical thrombectomy as the choice of treatment, a wide range of caveats remain unaddressed. Asian patients were rarely included in the trials, thereby raising the question of whether the treatment could be generalized. In addition, there remains a concern on the feasibility of the method with respect to its application against intracranial atherosclerosis (ICAS)-related LVO, frequently observed in the Asian population. It is important to include evidence on ICAS LVO from Asian countries in the future for a comprehensive understanding of LVO etiology. Besides the issues with EVT, prognostic concerns in diabetes patients, acute kidney injury following EVT, neuroprotective management against reperfusion injury, and other peri-EVT issues should be considered in clinical practice. In the current article, we present an in-depth review of the literature that revises information pertaining to such concerns.

Maximizing the catheter-to-vessel size optimizes distal flow control resulting in improved revascularization in vitro for aspiration thrombectomy

Background

Balloon guide catheters (BGCs) achieve proximal flow control during thrombectomy but antegrade intracranial flow often persists via the Circle of Willis. Closely sizing an aspiration catheter to the target vessel might achieve greater flow control and improve technical performance. Our objective was to measure the impact of aspiration catheter size on distal flow control and flow reversal with and without the use of BGCs. Clot retrieval testing was performed to establish the impact of these parameters on revascularization.

Methods

An in vitro thrombectomy model replicated in vivo conditions. Flow was measured continuously using ultrasonic flow sensors placed 20 cm distal to the catheter tip in the middlel cerebral artery (MCA). Four aspiration catheters of increasing size were evaluated: ACE 60 and 64 (Penumbra), SOFIA Plus (MicroVention), and Millipede 088 (Perfuze). Two clot analog types (red blood cell-rich and fibrin/platelet-rich) were used for clot retrieval testing.

Results

The larger area of the ‘superbore’ Millipede 088 catheter resulted in a larger reduction in antegrade flow than standard aspiration catheters, even when the latter were combined with a BGC. During aspiration, 6Fr catheters were unable to cause flow reversal in the distal MCA while the Millipede 088 achieved significant distal flow reversal (−146 mL/min) (P<0.0001*) (*denotes significance). The solo use of Millipede 088 resulted in better recanalization outcomes and significantly reduced distal emboli for internal carotid artery (P=0.015*) and MCA (P=0.014*) occlusions compared with all other devices and combinations.

Conclusions

Maximizing the catheter-to-vessel size facilitates near flow-arrest on catheter insertion, potentially negating the need for a BGC. A 0.088 inch aspiration catheter enables significant flow reversal in the distal MCA during aspiration.

Thrombus Composition and Efficacy of Thrombolysis and Thrombectomy in Acute Ischemic Stroke

Thrombi retrieved from patients with acute ischemic stroke are highly heterogeneous. Recent data suggest that thrombus composition may impact on mechanical thrombectomy, the number of recanalization manoeuvres, resistance to retrieval, and on thrombolytic potential. Our aim was to summarize evidence describing the impact of thrombus composition on efficacy of mechanical thrombectomy and thrombolysis in patients with acute ischemic stroke. The scoping review methodology guided by the Joanna Briggs Institute, an adaption of the Arksey and O'Malley, was followed. Comprehensive searches were conducted in MEDLINE, EMBASE, SCOPUS, and Web of Science. Articles were classified into 4 key themes: (1) composition of stroke thrombi, (2) thrombus composition and mechanical thrombectomy, (3) thrombus composition and thrombolytic therapy, and (4) novel imaging and endovascular approaches. Our search identified 698 articles published from 1987 to June 2020. Additional articles were extracted from reference lists of the selected articles. Overall, 95 topic-specific articles identified for inclusion published in 40 different journals were included. Reports showed that thrombus composition in stroke was highly heterogeneous, containing fibrin, platelets, red blood cells, VWF (von Willebrand Factor), and neutrophil extracellular traps. Thrombi could roughly be divided into fibrin- and red blood cell-rich clots. Fibrin-rich clots were associated with increased recanalization manoeuvres, longer procedure time, and less favorable clinical outcomes compared with red blood cell-rich clots. Advances in detection or treatment of thrombi that take into account clot heterogeneity may be able to improve future endovascular and thrombolytic treatment of stroke.

Balloon guide catheter improvements in thrombectomy outcomes persist despite advances in intracranial aspiration technology

BACKGROUND

First-pass effect (FPE) has been established as a key metric for technical success and strongly correlates with better clinical outcomes. Most data supporting improved outcomes with the use of a balloon guide catheter (BGC) predate the advent of last-generation large-bore intracranial aspiration catheters. We aim to evaluate the impact of BGC in FPE and clinical outcomes in a large cohort of patients treated with contemporary technology.

METHODS

Patients were recruited from the prospectively ongoing ROSSETTI registry. This registry includes all consecutive patients with anterior circulation large-vessel occlusion (LVO) from 10 comprehensive stroke centers in Spain. Demographic, clinical, angiographic, and clinical outcome data were compared between BGC and non-BGC groups. FPE was defined as the achievement of mTICI2c-3 after a single device pass.

RESULTS

426 patients were included out of which 271 (63.62%) used BCG. BGC-treated patients had higher FPE rate (45.8% vs 27.7%; P<0.001), higher final mTICI ≥2 c recanalization rate (76.8% vs 50.3%, respectively; P<0.001), shorter procedural time [median (IQR), 30 (19-58) vs 43 (33-71) min; P<0.001], higher NIHSS difference from admission to 24 hours [median (IQR), 8 (2-12) vs 3 (0-10); P=0.001], and lower mortality rate (17.6% vs 29.8%, P=0.026) compared with non-BGC patients. BGC use was an independent predictor of FPE (OR 2.197, 95% CI 1.436 to 3.361; P<0.001), and excellent clinical outcome at 3 months (OR 0.34, 95% CI 0.17 to 0.68; P=0.002).

CONCLUSIONS

Our results support the benefit of BGC use on angiographic and clinical outcomes in anterior circulation LVO ischemic stroke remain significant even when considering recent improvements in intracranial aspiration technology.

Clot Meniscus Sign: An Angiographic Clue for Choosing between Stent Retriever and Contact Aspiration in Acute Basilar Artery Occlusion

BACKGROUND AND PURPOSE

The efficacy of mechanical thrombectomy methods may differ depending on the characteristics of the occlusion. The purpose of this study was to compare the recanalization efficacy and treatment outcome of a stent retriever versus contact aspiration in patients with acute basilar artery occlusion according to the angiographic characteristics of the occlusion.

MATERIALS AND METHODS

One hundred sixty-one patients with acute basilar artery occlusion who underwent mechanical thrombectomy were retrospectively analyzed. A stent retriever was compared with contact aspiration thrombectomy according to the clot meniscus sign, defined as a meniscoid/tram-track-like sidewall contrast opacification of the thrombus. A propensity score matching analysis was performed. Clinical/angiographic characteristics and treatment and clinical outcomes were compared.

RESULTS

Overall, a stent retriever (n = 118) and contact aspiration (n = 43) did not show significant differences in the successful recanalization (82.2% versus 86.0%) and good clinical outcome rates (32.2% versus 39.5%). In patients with the positive meniscus sign, contact aspiration was associated with shorter procedural time (44 versus 26 minutes, P = .018), a lower number of passes (2 versus 1, P = .041), a higher complete recanalization rate (58.8% versus 85.7%, P = .021), and a higher rate of first-pass effect (27.9% versus 53.6%, P = .031) compared with a stent retriever. After propensity score matching, contact aspiration was associated with higher complete recanalization rates (59.3% versus 85.7%, P = .033). No significant differences in the outcomes were noted between a stent retriever and contact aspiration in patients negative for the meniscus sign.

CONCLUSIONS

The efficacy of the mechanical thrombectomy techniques may differ according to the angiographic characteristics of occlusion in patients with basilar artery occlusion. Contact aspiration may be more effective in terms of recanalization compared with a stent retriever in patients with the clot meniscus sign.

Duration of symptomatic stroke and successful reperfusion with endovascular thrombectomy for anterior circulation large vessel occlusive stroke

BACKGROUND

It has been reported that longer time intervals from stroke onset to endovascular therapy are associated with lower rates of successful reperfusion in acute ischemic stroke patients with large vessel occlusion. However, procedural variables and potential mechanisms of this association have not been fully elucidated.

METHODS

We performed a secondary analysis of individual patient data from the North American Solitaire Stent Retriever Acute Stroke (NASA) and Trevo Stent-Retriever Acute Stroke (TRACK) registries. We included patients with occlusion of the internal carotid artery or middle cerebral artery (M1 and M2 segments) who were treated by mechanical thrombectomy within 24 hours of last known normal. The primary outcome was reperfusion, defined as a Thrombolysis In Cerebral Infarction (TICI) score ≥2b. The secondary outcome was reperfusion on the first pass. The primary predictor was duration of symptomatic stroke, defined as time from last known normal to time of final pass. Adjusted logistic regression models were utilized to determine associations between variables and outcome.

RESULTS

We included 506 patients, of which 401 (79.3%) achieved successful reperfusion (TICI 2b/3). The mean (SD) duration of symptomatic stroke was 6.8 (3.5) hours and in the adjusted logistic regression model the duration of symptomatic stroke was associated with reperfusion (OR 0.90, 95% CI 0.84 to 0.96) and reperfusion on the first pass (OR 0.89, 95% CI 0.83 to 0.95). In that model, the predicted probability of reperfusion was 88% (95% CI 0.83 to 0.92) at 1 hour, 81% (95% CI 0.78 to 0.84) at 6 hours, 70% (95% CI 0.63 to 0.77) at 12 hours, and 42% (95% CI 0.17 to 0.67) at 24 hours (p_trend=0.001). Reperfused patients were significantly younger, more likely to be male, and to have had a balloon guide catheter used during the procedure.

CONCLUSION

In a real-world cohort of acute ischemic stroke patients with anterior circulation occlusion treated with endovascular therapy, longer duration of symptomatic stroke is associated with lower rates of successful reperfusion and reperfusion on the first pass.

Similarities and Differences Between Primary Percutaneous Coronary Intervention and Mechanical Thrombectomy

Acute ischemic stroke is among the leading causes of mortality and disability worldwide. Since 2015, as was the case for primary percutaneous coronary intervention for acute myocardial infarction, catheter-based reperfusion via mechanical thrombectomy (MT) has become the gold-standard treatment for acute ischemic stroke caused by large-vessel occlusion. Despite that, only a fraction of the world's population currently would be able to undergo MT in time, mostly because of the scarcity of 24/7 coverage by neurointerventionalists to deal with this enormous burden. Interventional cardiologists have thus been considered a logical option to aid in combating this vast demand to diminish the burden of acute ischemic stroke. However, despite some seemingly evident similarities between primary percutaneous coronary intervention and MT, for interventional cardiologists to enter this new field, they must be well trained and fully aware of all the clinical, technical, and environmental differences between these two scenarios. The main objective of this state-of-the-art paper is to serve as an introductory and comprehensive guide to familiarize the interventional cardiology community with the most critical technical aspects of MT.

Biomechanics and hemodynamics of stent-retrievers

In 2015, multiple randomized clinical trials showed an unparalleled treatment benefit of stent-retriever thrombectomy as compared to standard medical therapy for the treatment of a large artery occlusion causing acute ischemic stroke. A short time later, the HERMES collaborators presented the patient-level pooled analysis of five randomized clinical trials, establishing class 1, level of evidence A for stent-retriever thrombectomy, in combination with intravenous thrombolysis when indicated to treat ischemic stroke. In the years following, evidence continues to mount for expanded use of this therapy for a broader category of patients. The enabling technology that changed the tide to support endovascular treatment of acute ischemic stroke is the stent-retriever. This review summarizes the history of intra-arterial treatment of stroke, introduces the biomechanics of embolus extraction with stent-retrievers, describes technical aspects of the intervention, provides a description of hemodynamic implications of stent-retriever embolectomy, and proposes future directions for a more comprehensive, multi-modal endovascular approach for the treatment of acute ischemic stroke.

Endovascular treatment of acute ischemic stroke

Endovascular treatment of acute ischemic stroke has become the first choice of treatment in large cerebral vessel occlusions, with a very high efficacy in terms of revascularization and reducing disability of affected patients. Revolutionizing acute therapy, it induced important paradigm shifts in the concepts of time and salvageable brain. In this review we focus on the current concepts of patient selection, imaging, techniques and perspectives of endovascular stroke treatment.

Endovascular stroke treatment using balloon guide catheters may reduce penumbral tissue damage and improve long-term outcome

Objectives

During mechanical recanalization of large vessel occlusions (LVO), the use of proximal flow arrest with balloon guide catheters (BGC) was shown to be associated with better angiographic and even clinical outcome. The aim of the study was to analyze the impact of BGC use on microstructural alterations in the salvaged penumbra.

Methods

All patients who underwent mechanical recanalization of LVO of the anterior circulation were reviewed within a prospective stroke registry of a single comprehensive stroke center. Fifty-two patients received an admission CT perfusion together with post-interventional diffusion tensor imaging. Technical details such as BGC usage were correlated with microstructural integrity changes of the salvaged gray matter through the mean diffusivity (MD) index. Moderation analysis was performed to test the interaction of BGC on the correlation between angiographic and clinical outcomes.

Results

For all patients with complete reperfusion, microstructural integrity changes with lowered MD index were found within the salvaged penumbra for cases of non-BGC usage (mean − 0.02) compared to cases with BGC usage (0.01, p = 0.04). The importance of complete reperfusion for good clinical outcome is predominantly based on patients treated with BGC (effect 2.78, p = 0.01 vs. for non-BGC: 0.3, p = 0.71).

Conclusions

The lowered MD index early after mechanical recanalization without BGC usage can be interpreted as microstructural ischemic damage of the salvaged penumbra. It was shown that achieving complete reperfusion in a setting of BGC usage with proximal flow arrest minimizes penumbral damage and improves long-term outcomes.

Key Points

• Microstructural ischemic damage can be reduced by using proximal flow arrest during endovascular treatment with balloon guide catheter.

• Complete reperfusion in a setting of balloon guide catheter minimizes penumbral damage and improves long-term outcome.

Electronic supplementary material

The online version of this article (10.1007/s00330-020-07260-3) contains supplementary material, which is available to authorized users.

The Therapeutic Effects of Endovascular Therapy with mTICI2b and 3 Recanalization for Acute Anterior Circulation Stroke Patients

BACKGROUND AND PURPOSE

Modified Thrombolysis in Cerebral Infarction (mTICI)2b/3 has been considered the criterion for successful reperfusion in endovascular treatment. This study aimed to compare the therapeutic safety and efficacy of mTICI2b and mTICI3 recanalization, and to analyze the factors related to outcomes in everyday clinical practice.

MATERIALS AND METHODS

This is a single-center retrospective analysis of 224 patients who underwent successful thrombectomy (achieving a mTICI score ≥2b). The primary outcomes included a modified Rankin score (mRS) of 0-2 at 90-day, mortality, and symptomatic intracranial hemorrhage.

RESULTS

A total of 111 patients achieved mTICI2b status (49.6%), and 113 achieved mTICI3 status (50.4%). The comparison between mTICI2b and 3 reperfusions showed no differences in short-term outcomes, 90-day mRS, complications, and mortality. There was a trend toward more passes in mTICI2b patients, although the difference was not significant. The univariate analysis showed that poor outcomes after endovascular treatment were associated with older age, previous history of coronary heart disease, atrial fibrillation, diabetes, tandem occlusions, high National Institutes of Health Stroke Scale (NIHSS) score on admission, and general anesthesia. A previous history of coronary heart disease, a high NIHSS score on admission, and the use of general anesthesia were independent factors that affected the therapeutic effects.

CONCLUSION

The superiority (efficacy and safety) of mTICI3 reperfusion was not significant compared with that of mTICI2b reperfusion. Prolonged efforts to achieve mTICI3 after achieving mTICI2b should be considered prudently for those with difficulty achieving 100% reperfusion.

Mechanical Thrombectomy for Large Vessel Occlusion via the Transbrachial Approach: Case Series

Mechanical thrombectomy has become a standard treatment for acute ischemic stroke with large vessel occlusion. In aged patients, it is difficult to guide the catheter via the transfemoral approach due to vessel tortuosity and aortic elongation. We report our preliminary clinical experience using the transbrachial approach. Among the 119 patients who underwent thrombectomy from April 2018 to December 2019, a total of 5 patients were treated via the transbrachial approach. Clinical outcomes were retrospectively analyzed. Successful reperfusion was achieved in 4 out of 5 cases. There was 1 death due to symptomatic intracranial hemorrhage. One patient had a good outcome at discharge. There were no access-site complications associated with any of these cases. Transbrachial access for mechanical thrombectomy is feasible and can provide an alternative to the transfemoral approach.

Mechanical thrombectomy for occlusion near a ruptured intracranial aneurysm: A case report

Background:

While recent randomized clinical trials have shown the efficacy of mechanical thrombectomy for acute large vessel anterior cerebral occlusion, cases in patients with a subarachnoid hemorrhage (SAH) were excluded from the study.

Case Description:

A 58-year-old man presented with a SAH as a result of a ruptured middle cerebral artery aneurysm. Coil embolization was performed, and a right intracranial angiography showed remnants of an aneurysmal neck. However, the following angiography also revealed a thromboembolic complication that occurred in the same territory as the ruptured aneurysm. The patient underwent a rescue mechanical thrombectomy under the working projection. We deployed a retrieval stent without covering the aneurysmal neck. The occluded vessel was recanalized without any hemorrhagic complication. Due to minimal intracerebral infarction, the patient had good outcomes.

Conclusion:

Mechanical thrombectomy is a useful option to retrieve a clot from an occluded intracranial vessel located near a ruptured aneurysm. Approaching the clot at the working projection is important to ensure safety in the setting of a ruptured aneurysm.

Predictors of Successful First-Pass Thrombectomy with a Balloon Guide Catheter: Results of a Decision Tree Analysis

Complete recanalization after a single retrieval maneuver is an interventional goal in acute ischemic stroke and an independent factor for good clinical outcome. Anatomical biomarkers for predicting clot removal difficulties have not been comprehensively analyzed and await unused. We retrospectively evaluated 200 consecutive patients who suffered acute stroke and occlusion of the anterior circulation and were treated with mechanical thrombectomy through a balloon guide catheter (BGC). The primary objective was to evaluate the influence of carotid tortuosity and BGC positioning on the one-pass Modified Thrombolysis in Cerebral Infarction Scale (mTICI) 3 rate, and secondarily, the influence of communicating arteries on the angiographic results. After the first-pass mTICI 3, recanalization fell from 51 to 13%. The regression models and decision tree (supervised machine learning) results concurred: carotid tortuosity was the main constraint on efficacy, reducing the likelihood of mTICI 3 after one pass to 30%. BGC positioning was relevant only in carotid arteries without elongation: BGCs located in the distal internal carotid artery (ICA) had a 70% probability of complete recanalization after one pass, dropping to 43% if located in the proximal ICA. These findings demonstrate that first-pass mTICI 3 is influenced by anatomical and interventional factors capable of being anticipated, enabling the BGC technique to be adapted to patient’s anatomy to enhance effectivity.

Comparison of FlowGate2 and Merci as balloon guide catheters used in mechanical thrombectomies for stroke intervention

The present study reports on the usefulness of FlowGate² (FG2) as a novel balloon guide catheter (BGC) for mechanical thrombectomy (MT) treatment. MT using a BGC device was performed on 255 patients at the authors' institution (St. Vincent's hospital, Suwon, Korea and Hangang Sacred Heart Hospital, Seoul, Korea) between January 2014 and September 2018. A total of 235 patients underwent successful application of BGCs and were divided into two groups; an FG2 and a Merci group, and a comparative analysis was performed. The failure rate in the FG2 group (2.5%) was significantly lower than that in the Merci group (10.8%; P=0.016). Occurrence of distal emboli was significantly lower in the FG2 group (4.7%) than in the Merci group (7.3%; P=0.012). According to subgroup analysis of the BGC and the intermediate catheter, the incidence rate of the distal emboli in the FG2 with an intermediate catheter (2.3%) was significantly lower than that of the Merci with an intermediate catheter (6.6%; P=0.038). The ratio of thrombolysis in cerebral infarction (TICI) 3 recanalization in the first pass was higher in the FG2 group than in the Merci group, in both total (44.7 vs. 34.7%; P=0.033) and subgroup patients (46.5 vs. 34.4%; P=0.029). In the multivariate analysis, use of an intermediate catheter [odds ratio (OR), 0.75; 95% confidence interval (CI), 0.66-0.94; P=0.029] and FG2 application (OR, 0.59; 95% CI, 0.25-0.93; P=0.020) were the predictive factors for fewer distal emboli. In summary, FG2 BGC enables an effective MT with less application failures and occurrence of distal emboli, and higher TICI 3 recanalization at the first stent passage, compared with Merci BGC.

Evolution of Stroke Thrombectomy Techniques to Optimize First-Pass Complete Reperfusion

Since 2015, endovascular therapy (EVT) has become the standard of care for acute ischemic stroke (AIS) due to large vessel occlusion. It is a safe and highly effective treatment, and its number needed to treat of 2.6 is one of the highest throughout medicine. The ultimate goal when performing EVT is to maximize chances of good outcome through achievement of fast first-pass complete reperfusion, as incomplete and delayed reperfusion increases complication rates and negatively affects outcome. Since EVT has been established as standard of care, new devices have been developed and treatment techniques have been refined. This review provides a brief overview about the rationale for and history of EVT, followed by a detailed step-by-step description of how to perform EVT using the BADDASS (BAlloon guide with large bore Distal access catheter with Dual Aspiration with Stent-retriever as Standard approach), a combined technique, which is in our opinion the safest and most effective way to achieve fast first-pass complete reperfusion. We also discuss treatment strategies for patients with simultaneous high-grade carotid stenosis/pseudoocclusion/occlusion and gaining carotid access in challenging arch anatomy, as these are commonly encountered situations in AIS, and conclude with an outlook on new technologies and future directions of EVT.

Transcirculation Approach for Mechanical Thrombectomy in Acute Ischemic Stroke: A Multicenter Study and Review of the Literature

Background: Transcirculation approaches, which consist of primary catheterization of a target artery from the contralateral side or opposite cerebral circulation, provide alternate endovascular routes when anterograde interventions are not feasible. We aimed to assess the safety and efficacy of mechanical thrombectomy (MT) through a transcirculation route.

Methods: Six centers provided retrospective data on acute ischemic stroke (AIS) patients who underwent MT via transcirculation approaches. Demographics and technical details of the endovascular intervention were collected. Recanalization rates, peri-procedural complications and clinical/angiographic outcomes immediately after the procedure and at last available follow-up were assessed. A review of the literature reporting on AIS patients whom underwent transcirculation MT was also performed.

Results: Our multicenter study included 14 AIS patients treated through transcirculation routes. Mean age was 57.8 ± 11.9 years, and 10 (71.4%) were men. Mean NIHSS at admission was 18.4 (range 8–27). TICI 2b-3 recanalization was achieved in 10/14 (71.4%) patients. Three patients died after intervention: one due to late recanalization, one due to acute in-stent thrombosis, and one due to a procedure-related thromboembolic brainstem infarct. Of 11 surviving patients with follow-up available (mean 9.7 months), mRS 0–2 was achieved in 6 (54.5%) cases. Our review of the literature pooled a total of 37 transcirculation MT cases. Most common occlusions were tandem lesions (ICA + MCA = 64.9%) and BA + bilateral VA (18.9%). ACOM and PCOM were crossed in 18 (48.6%) cases each; one patient required a combined ACOM-PCOM approach. Primary recanalization technique included intra-arterial (IA) thrombolytics alone in 10 (27%), angioplasty ± stenting in 6 (16.2%), stent-retriever in 8 (21.6%), contact aspiration in 6, and combined (MT ± IA-thrombolytics) in 6 cases. Twenty-eight (75.7%) AIS patients achieved successful TIMI 2-3/TICI 2b-3 recanalization. After a mean follow-up of 6.7 months, 23/31 (74.2%) patients achieved a favorable functional outcome.

Conclusions: Transcirculation approaches may be used to access the target lesion when the parent artery cannot be crossed through conventional antegrade routes. These techniques are feasible but should be reserved as a bailout maneuver when anterograde MT is not possible. Newer endovascular devices have improved neurological and angiographic outcomes in transcirculation cases.

Identifying the predictors of first-pass effect and its influence on clinical outcome in the setting of endovascular thrombectomy for acute ischemic stroke: Results from a multicentric prospective registry

BACKGROUND

The first-pass effect, defined as a complete or near-complete recanalization after one pass (first-pass effect) of a mechanical thrombectomy device, has been related to better clinical outcome than good recanalization after more than one pass in acute ischemic stroke. We searched for predictors of first-pass effect by analyzing the results within a large prospective multicentric registry.

METHODS

We included patients treated by mechanical thrombectomy for isolated anterior intracranial occlusions. A multi-variate logistic regression analysis was carried out to search for predictors of first-pass effect. We also analyzed the percentage of patients with 90-day modified Rankin Scale score 0 to 2, excellent outcome (90-day modified Rankin Scale 0 to 1), 24-h NIHSS change, and 90-day all-cause mortality.

RESULTS

Among the 1832 patients included, clinical outcome at 90 days was significantly better in first-pass effect patients (50.6% vs. 38.9% in patients without first-pass effect), with a center-adjusted OR associated with first-pass effect of 1.74 (95%CI, 1.24 to 1.77). Older age, a lower systolic blood pressure, an MCA-M1 occlusion, higher DWI-ASPECTS at admission, mechanical thrombectomy under local anesthesia, and combined first-line device strategy were independent predictors of first-pass effect.

CONCLUSIONS

In this study, a strategy combining thrombectomy and thrombo-aspiration was more effective than other strategies in achieving first-pass effect. In addition, we confirm that clinical outcome was better in patients with first-pass effect compared to non-first-pass effect patients.

Effect of Balloon Guide Catheter Utilization on the Incidence of Sub-angiographic Peripheral Emboli on High-Resolution DWI After Thrombectomy: A Prospective Observational Study

Background: Thrombus fragmentation causing distal emboli is a feared complication during mechanical thrombectomy (MT). We aimed to investigate the impact of procedural parameters and thrombus properties on the incidence of peripheral emboli after MT for large vessel occlusions (LVO).

Methods: We performed a prospective analysis of patients with LVO stroke successfully treated with MT, defined as a score of 2b, 2c, or 3 on the thrombolysis in cerebral infarction (TICI) scale. A follow-up MRI including high-resolution diffusion-weighted imaging (DWI) was performed within 24 h following MT. The primary endpoint was the number and volume of peripheral emboli, classified as punctuate DWI lesions distant to the diffusion-restricted core lesion. Further analysis included the influence of baseline characteristics, procedural and outcome parameters, and thrombus properties on peripheral emboli.

Results: Thirty-seven patients with successful MT met the inclusion criteria. Use of a balloon guide catheter (BGC) and TICI were the only independent predictors for a reduced number of peripheral emboli. The use of a BGC led to a significant reduction in the number and volume of peripheral emboli, with a median number/volume of peripheral emboli of 4.5/287 μl (IQR 1.25–8.25/76–569 μl) vs. 12/938 μl (IQR 4–19/242–1,836 μl). In cases where BGC was not employed, the number of peripheral emboli increased with decreasing TICI scores.

Conclusions: BGC-aided MT reduces the number of peripheral emboli in successful but incomplete reperfusion (TICI 2b and 2c). The effectiveness of this strategy therefore goes above and beyond that which can be demonstrated by the TICI score alone.

Comparison of Aspiration versus Stent Retriever Thrombectomy as the Preferred Strategy for Patients with Acute Terminal Internal Carotid Artery Occlusion: A Propensity Score Matching Analysis

BACKGROUND AND PURPOSE

There is no consensus on endovascular treatment for terminal ICA. The purpose of this study was to evaluate the comparative safety and efficacy of preferred aspiration thrombectomy and stent retriever thrombectomy for revascularization in patients with isolated terminal ICA occlusion.

MATERIALS AND METHODS

We conducted a retrospective analysis of patients with terminal ICA occlusion treated with aspiration thrombectomy or stent retriever thrombectomy in our center, from September 2013 to November 2018. To minimize the case bias, propensity score matching was performed. The primary outcomes were successful reperfusion defined by expanded TICI grades 2b-3 at the end of all endovascular procedures and puncture-to-reperfusion time.

RESULTS

A total of 109 consecutive patients with terminal ICA occlusion were divided into the aspiration thrombectomy group (40 patients) and the stent retriever thrombectomy group (69 patients), and 30 patients were included in each group after propensity score matching. The proportion of complete reperfusion was significantly higher in the aspiration thrombectomy group (OR 4.75 [95% CI, 1.10-1.38]; P = .002). The median puncture-to-reperfusion time in the aspiration thrombectomy group was shorter than that in the stent retriever thrombectomy group (38  versus 69 minutes; P = .001). Fewer intracerebral hemorrhage events were recorded in the aspiration thrombectomy group (OR 0.29 [95% CI, 0.09-0.90]; P = .028). No significant differences were observed for good outcomes (OR 1.92 [95% CI, 0.86-4.25]) and mortality (OR 0.84 [95% CI, 0.29-2.44]) at 90 days.

CONCLUSIONS

For the treatment of terminal ICA occlusion, aspiration thrombectomy was technically superior to stent retriever thrombectomy in the absence of a balloon guide catheter in achieving successful reperfusion with shorter puncture-to-reperfusion time and procedure-related adverse events.

Direct Brachial Approach for Acute Basilar Artery Occlusion: Technical Note and Preliminary Clinical Experience

In mechanical endovascular thrombectomy (MET) for acute basilar artery occlusion (ABAO) in the elderly, navigating a guide catheter via the femoral artery may be difficult due to the approach route’s significant tortuosity. To resolve this problem, we have been performing a technique that uses a direct brachial approach (DiBA) with a large-bore aspiration catheter. We reported our preliminary clinical experience with this technique. MET for ABAO using the DiBA technique was performed on 4 consecutive patients between August 2017 and December 2018. In all patients, thrombolysis in cerebral infarction 2B or 3 recanalization was achieved, but the modified Rankin Scale at 90 days was ≥4. There were no technical difficulties or complications with this technique. The DiBA technique is an effective and feasible approach in MET for ABAO. Although excellent clinical outcomes could not be achieved, the angiographic outcomes were excellent with no technical complications. This approach can be an alternative to the femoral artery approach, particularly for tortuous arteries in the elderly.

Endovascular Treatment of Acute Ischemic Stroke

급성 허혈성 뇌졸중은 심각한 후유증이나 사망에 이르는 가장 큰 원인 질환들 중 하나이다. 제2세대 혈전제거기구가 도입된 이후로 급성 허혈성 뇌졸중에서 혈관 내 재개통 치료는 급속히 발전해 왔고, 최근에는 표준 치료 중의 하나가 되었다. 이 종설에서는 급성 허혈성 뇌졸중에서 혈관 내 치료와 고식적인 치료를 무작위 배정으로 비교한 임상 연구들의 결과를 간략히 기술하고, 새로이 개정된 급성 허혈성 뇌졸중에서의 혈관 내 치료의 적응증과, 현재 혈관내 치료에 쓰이는 기구들과 방법에 대해 알아보고자 한다.

Impact of Periprocedural and Technical Factors and Patient Characteristics on Revascularization and Outcome in the DAWN Trial

Background and Purpose- Because of unique attributes of mechanical thrombectomy performed between 6 and 24 hours after symptom onset in acute ischemic stroke patients, it is not known if predictors of angiographic recanalization and favorable outcome in patients treated with thrombectomy in the late (6-24 hour) time window are similar to those treated in the early time window. Methods- We analyzed data from the DAWN trial (DWI or CTP Assessment With Clinical Mismatch in the Triage of Wake-Up and Late Presenting Strokes Undergoing Neurointervention With Trevo) which enrolled patients with symptom onset 6 to 24hours after last known well and occlusion of the intracranial internal carotid artery or proximal middle cerebral artery with a mismatch between severity of clinical deficit and infarct core volume as identified by computed tomography-perfusion or diffusion magnetic resonance imaging. We evaluated the effect of tandem occlusions, periprocedural heparin use, procedural speed (from puncture to procedure completion), general anesthesia, balloon-guide catheters, thrombectomy device size, and number of passes on substantial reperfusion (modified Thrombolysis in Cerebral Infarction 2b/3) and on likelihood of obtaining a modified Rankin Scale at 3 months indicating functional independence. Results- Of 107 patients who underwent MT in the interventional arm of DAWN, substantial reperfusion and modified Rankin Scale score 0 to 2 at 3 months was seen in 90 (84%) and 52 (49%), respectively. In univariate analysis, general anesthesia (odds ratio [OR] 0.27; P=0.042) and ≥3 passes with stent retriever (OR, 0.17; P=0.002) were inversely associated with substantial reperfusion. In multivariate analyses, only ≥3 passes were associated with lack of revascularization (OR, 0.17; P=0.002). in univariate analysis ≥3 passes (OR, 0.24; P =0.003) and baseline National Institutes of Health Stroke Scale score >17 (OR, 0.19; P<0.001) were inversely associated with functional independence at 3 months. In multivariate analyses, ≥3 passes (OR, 0.24; P=0.003) and National Institutes of Health Stroke Scale score >17 (OR, 0.19; P<0.001) remained inversely associated with favorable outcome at 3 months. Conclusions- Patients requiring ≥3 thrombectomy passes had reduced substantial reperfusion and favorable outcome at 3 months in DAWN. Whether or not additional thrombectomy techniques beyond ≥3 thrombectomy passes with the Trevo stent retriever are beneficial for patient outcomes in this patient population remains to be clarified by future studies. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT02142283.

Effect of balloon guide catheter utilization on contact aspiration thrombectomy

OBJECTIVE

The role of the balloon guide catheter (BGC) has not been evaluated in contact aspiration thrombectomy (CAT) for acute stroke. Here, the authors aimed to test whether the BGC was associated with recanalization success and good functional outcome in CAT.

METHODS

All patients who had undergone CAT as the first-line treatment for anterior circulation intracranial large vessel occlusion were retrospectively identified from prospectively maintained registries for six stroke centers. The patients were dichotomized into BGC utilization and nonutilization groups. Clinical findings, procedural details, and recanalization success rates were compared between the two groups. Whether the BGC was associated with recanalization success and functional outcome was assessed.

RESULTS

A total of 429 patients (mean age 68.4 ± 11.4 years; M/F ratio 215:214) fulfilled the inclusion criteria. A BGC was used in 45.2% of patients. The overall recanalization and good outcome rates were 80.2% and 52.0%, respectively. Compared to the non-BGC group, the BGC group had a significantly reduced number of CAT passes (2.6 ± 1.6 vs 3.4 ± 1.5), shorter puncture-to-recanalization time (56 ± 27 vs 64 ± 35 minutes), lower need for the additional use of thrombolytics (1.0% vs 8.1%), and less embolization to a distal or different site (0.5% vs 3.4%). The BGC group showed significantly higher final (89.2% vs 72.8%) and first-pass (24.2% vs 8.1%) recanalization success rates. After adjustment for potentially associated factors, BGC utilization remained independently associated with recanalization (OR 4.171, 95% CI 1.523-11.420) and good functional outcome (OR 2.103, 95% CI 1.225-3.612).

CONCLUSIONS

BGC utilization significantly increased the final and first-pass recanalization rates and remained independently associated with recanalization success and good functional outcome.

Economic challenges of using innovative medical devices in major public health pathologies: Example of acute ischemic stroke management by mechanical thrombectomy

BACKGROUND

Activity-based Funding can induce financial imbalances for health institutions if innovative medical devices (MD) used to perform acts are included in Diagnosis Related Groups (DRG) tariff. To be reimbursed in addition to the DRG tariff, innovative MD must have received a favorable evaluation by the French National Authority for Health (Haute Autorité de Santé) and be registered on the positive list. The aim of this study was to evaluate the expenses and incomes generated by each scenario (before and after the reimbursement of MD), and the financial reports. This study concerned the management of ischemic stroke by mechanical thrombectomy devices, in high-volume French hospital.

METHODS

All patients who have had an acute ischemic stroke and admitted to the interventional neuroradiology unit between January 2016 and December 2017 were included retrospectively in this monocentric study. They were divided into four subgroups based on the severity of the DRG. The cost study was carried out using the French National Cost Study Methodology adjusted for the duration of the stays and by micro-costing on MD.

RESULTS

A total of 267 patients were included. Over the study period, the average cost of the hospital stay was €10,492±6364 for a refund of €9838±6749 per patient. The acts performed became profitable once the MD were registered on the positive list (€-1017±3551 vs. €560±2671; P<0.05). Despite this reimbursement, this activity remained in deficit for DRG lowest severity (level 1) patients (€-492±1244). Specific MD used for mechanical thrombectomy represented 37% of the total cost of stay.

CONCLUSION

The time required to evaluate MD reimbursement files is too long compared to their development. As a result, practitioners are in difficulty to be able to carry out acts according to the consensual practices of their learned societies, without causing any financial deficit of their institutions.

Role of Balloon Guide Catheter in Modern Endovascular Thrombectomy

Proximal flow control achieved with a balloon guide catheter (BGC) during endovascular treatment of acute ischemic stroke is reviewed in this article. In clinical practice, BGCs offer a multi-faceted approach for clot retrieval by creating proximal flow arrest, reducing embolic burden, and shortening procedure time. Evaluation of frontline thrombectomy procedures with BGCs revealed advantages of combined use over the conventional guide catheter (CGC), notably in the significant reduction of distal emboli to both the affected and previously unaffected territories. Recently, new measures of early and complete reperfusion at first thrombectomy pass have been identified as independent predictors of improved outcomes, which were consistently demonstrated with use of BGC as a safe and effective option to minimize number of passes during intervention. Prior randomized controlled trials reported the positive correlation between BGC-treated patients and a lower risk of mortality as well as shortened procedure time. While BGC use is more common in stent retriever-mediated mechanical thrombectomy, preliminary data has shown the potential benefit of device application during contact aspiration thrombectomy to achieve successful recanalization. However, the question of which major endovascular strategy reigns superior as a frontline remains to be answered. Along with clinical case assessments, BGC performance during in-vitro simulation was analyzed to further understand mechanisms for optimization of thrombectomy technique.

Effects of first pass recanalization on outcomes of contact aspiration thrombectomy

BACKGROUND

First pass recanalization (FPR, defined as achieving a modified Thrombolysis in Cerebral Ischemia (mTICI) grade 2c/3 with a single pass of a thrombectomy device) effect has not yet been evaluated in contact aspiration thrombectomy (CAT). We evaluated FPR effect on clinical outcomes and FPR predictors in CAT.

METHODS

All consecutive patients who underwent frontline CAT for anterior circulation large vessel occlusion with recanalization (mTICI 2b-3) were identified from registries at six stroke centers. The patients were dichotomized into FPR and non-FPR groups. Clinical features and outcomes were compared between the groups. Multivariate analyses were performed to determine whether FPR was independently associated with clinical outcomes and to identify predictors of FPR.

RESULTS

Of the 429 patients who underwent frontline CAT, recanalization was successful in 344 patients (80.2%; mean age 68.7±11.0 years; M:F ratio 179:165). The FPR group had a higher rate of good outcome (modified Rankin Scale score 0-2) than the non-FPR group. Furthermore, the good outcome rate was higher in the FPR group than in patients who achieved mTICI 2c/3 with multiple passes or rescue treatment. FPR (OR 2.587; 95% CI 1.237 to 5.413) remained independently associated with good outcomes, in addition to age, baseline National Institute Health Stroke Scale, and coronary artery disease. The use of a balloon guide catheter (OR 3.071; 95% CI 1.699 to 5.550) was the only predictor of FPR.

CONCLUSIONS

Patients in the FPR group had better clinical outcomes than the non-FPR group in CAT. FPR was independently associated with a good outcome. The use of a balloon guide catheter was the only predictor of FPR.

Predictors of Balloon Guide Catheter Assistance Success in Stent-retrieval Thrombectomy for an Anterior Circulation Acute Ischemic Stroke

Introduction Mechanical thrombectomy has become the standard treatment for large vessel occlusion (LVO) in acute ischemic stroke (AIS) in well-selected patients. Although many devices and strategies exist, the use of a balloon-tip guide catheter (BGC) with stent-retriever (SR) may hold several advantages. We aim to assess the efficacy and identify predictors of technical success of this unique approach. Methods From our prospectively maintained database, we identified consecutive cases in which a BGC was used for stent-retriever thrombectomy in anterior circulation LVO between 2015 and 2016. Baseline and procedural characteristics were captured and analyzed. Predictors of technical and clinical outcomes were identified by multivariable logistic regression analysis. Results Ninety-three patients with AIS-LVO were treated with BGC-assisted mechanical thrombectomy. The mean age was 71 years old (SD 14), with 49.5% male (n=46). Pre-operative IV-tPA was administered in 55.9% (n=52) of cases. The most common location of occlusive thrombus was M1 (64.5%, n=60). Successful recanalization (mTICI=2b-3) was achieved in 86.0% (n=80) of cases while complete revascularization (mTICI-3) was achieved in 56.5% (n=52). There was a first-pass success rate of 52.7% (n=49). At discharge, 38.7% of the patients were functionally independent (mRS≤2). Multivariate analysis revealed that the middle cerebral artery location was strongly predictive of first-pass success, resulting in mTICI =2b revascularization (OR 7.10, p=0.018). Additionally, female gender (OR 2.85, p=0.042) and decreasing mTICI were associated with a poor clinical outcome (mRS≥4; OR 1.76, p=0.008). Conclusions BGC assistance in stent retrieval thrombectomy is safe and effective for AIS due to anterior circulation LVO. Further investigation is required to elucidate the optimal treatment strategy based on patient and disease characteristics.

GUide sheath Advancement and aspiRation in the Distal petrocavernous internal carotid artery (GUARD) Technique during Thrombectomy Improves Reperfusion and Clinical Outcomes

BACKGROUND AND PURPOSE

Adjunctive techniques to stent retriever thrombectomy include balloon-guide catheters and/or distal access catheters for aspiration. We describe a novel technique using a flexible, 6 French 088 distal guide sheath advanced past the skull base to augment mechanical thrombectomy. We studied the relative safety and efficacy of this technique in the setting of a combined stent retriever-distal access catheter aspiration thrombectomy protocol.

MATERIALS AND METHODS

We performed a retrospective case-control study of intracranial internal carotid artery or M1-M2 middle cerebral artery occlusions requiring mechanical thrombectomy. Patients were divided into 2 groups based on thrombectomy techniques: conventional stent retriever with distal access catheter aspiration without (standard) and with adjunctive GUide sheath Advancement and aspiRation in the Distal petrocavernous internal carotid artery (GUARD). Using propensity score matching, we compared procedural safety, reperfusion efficacy using the modified Thrombolysis in Cerebral Infarction scale and clinical outcomes with the modified Rankin Scale.

RESULTS

In comparing the GUARD (45 patients) versus standard (45 matched case controls) groups, there were no significant differences in demographics, NIHSS presentations, IV rtPA use, median onset-to-groin puncture times, procedural complications, symptomatic intracranial hemorrhage, or mortality. The GUARD group demonstrated significantly higher successful mTICI ≥2b reperfusion rates (98% versus 80%, P = .015) and improved functional mRS ≤2 outcomes (67% versus 43%, P = .04), with independent effects of the GUARD technique confirmed in a multivariable logistic regression model.

CONCLUSIONS

The GUARD technique during mechanical thrombectomy with combined stent retrieval-distal access catheter aspiration is safe and effective in improving reperfusion and clinical outcomes.

Efficacy of Combining Proximal Balloon Guiding Catheter and Distal Access Catheter in Thrombectomy with Stent Retriever for Anterior Circulation Ischemic Stroke

OBJECTIVE

We evaluated efficacy of combining proximal balloon guiding catheter (antegrade flow arrest) and distal access catheter (aspiration at the site of occlusion) in thrombectomy for anterior circulation ischemic stroke.

METHODS

We retrospectively analyzed 116 patients who underwent mechanical thrombectomy with stent retriever. The patients were divided by the techniques adopted, the combined technique (proximal balloon guiding catheter and large bore distal access catheter) group (n=57, 49.1%) and the conventional (guiding catheter with stent retriever) technique group (n=59, 50.9%). We evaluated baseline characteristics (epidemiologic data, clinical and imaging characteristics) and procedure details (the number of retrieval attempts, procedure time), as well as angiographic (thrombolysis in cerebral infarction (TICI) score, distal thrombus migration) and clinical outcome (National Institutes of Health Stroke Scale at discharge, modified Rankin Scale [mRS] at 3 months) of them.

RESULTS

The number of retrieval attempts was lower (p=0.002) and the first-pass successful reperfusion rate was higher (56.1% vs. 28.8%; p=0.003) in the combined technique group. And the rate of final result of TICI score 3 was higher (68.4% vs. 28.8%; p<0.01) and distal thrombus migration rate was also lower (15.8% vs. 40.7%; p=0.021) in the combined technique group. Early strong neurologic improvement (improvement of National Institutes of Health Stroke Scale ≥11 or National Institutes of Health Stroke Scale ≤1 at discharge) rate (57.9% vs. 36.2%; p=0.02) and favorable clinical outcome (mRS at 3 months ≤2) rate (59.6% vs. 33.9%; p=0.005) were also better in the combined technique group.

CONCLUSION

The combined technique needs lesser attempts, decreases distal migration, increases TICI 3 reperfusion and achieves better clinical outcomes.

Evaluation of the Intracranial Flow Alteration during Manual Syringe and Continuous Pump Aspiration

GOALS

While mechanical thrombectomy (MT) has been shown to be effective in the treatment of acute large vessel occlusions, adjunctive measures, such as balloon guide catheters (BGC) and aspiration techniques, are utilized heterogeneously. Clarifying the effects of aspiration applied to the anterior cerebral circulation with proximal flow arrest can shed light on embolic protection during MT.

MATERIALS AND METHODS

Manual and pump aspiration were applied through a BGC in a synthetic cerebrovascular model with a 60 ml syringe and a Penumbra pump, respectively. Flow direction was observed during the procedure with fluorescent particles and ultraviolet light. Flow rates were monitored at the simulated internal carotid artery and middle cerebral artery (MCA).

FINDINGS

Both aspiration methods produced retrograde flow in all the modeled cerebrovascular segments. In the syringe aspiration methods, an interval phase occurred during the experimental trial in which suction forces paused and MCA flow became anterograde through posterior communication artery collateral circulation.

CONCLUSION

Flow patterns vary with different methods of aspiration. With proximal flow arrest, continuous aspiration methods induce constant retrograde flow in all vessels, whereas manual aspiration demonstrates various flow changes, including periods of anterograde flow during the procedure, which may be less effective at distal re-embolization prevention.

True First-Pass Effect

Background and Purpose- It has been hypothesized that in stroke patients, complete reperfusion (modified Thrombolysis in Cerebral Infarction; mTICI 3) after a single thrombectomy pass is a predictor for favorable outcome (modified Rankin Scale score, 0-2), but a true first-pass effect defined as improved clinical outcome after complete reperfusion with one versus multiple passes has not yet been specifically addressed in the literature. Methods- We compared clinical outcome of 164 consecutive patients with occlusions in the anterior circulation and known symptom onset, in whom we achieved complete reperfusion (mTICI 3), depending on whether complete reperfusion was achieved after a single thrombectomy pass (n=62) or multiple thrombectomy passes (n=102). To adjust for confounding factors such as prolonged time spans between symptom onset and reperfusion, additional administration of intra-arterial thrombolysis, and clot localization, we also compared clinical outcome of our first-pass group with a matched cohort (n=54) and a superselective subgroup of first-pass patients (only M1 occlusions, no additional intra-arterial thrombolysis; n=46) with its matched cohort (n=24). Results- Multivariable analysis of our cohort of 164 nonmatched patients revealed that there was a significant association between first-pass complete reperfusion and favorable clinical outcome (P=0.013). This was confirmed in our case-control analyses (P=0.010 and P=0.042). In our matched cohorts, favorable clinical outcome was seen almost twice as often if complete reperfusion was achieved after one pass (62% and 67% versus 36% and 37%), and odds for favorable outcome were 2.4 to 3.2× higher (CIs, 1.1-4.8 and 1.0-9.9). Conclusions- First-pass complete reperfusion is an independent factor for favorable outcome and should be aimed for in mechanical thrombectomy.

Procedural approaches and angiographic signs predicting first-pass recanalization in patients treated with mechanical thrombectomy for acute ischaemic stroke

BACKGROUND

First-pass recanalization via mechanical thrombectomy (MT) has been associated with improved clinical outcome in patients with acute ischaemic stroke. The optimal approach to achieve first-pass effect (FPE) remains unclear. No study has evaluated angiographic features associated with the achievement of FPE. We aimed to determine the procedural approaches and angiographic signs that may predict FPE.

METHODS

We performed a prospective, multi-centre, observational study of FPE in patients with anterior circulation stroke treated with MT between February and June 2017. MTs were performed using different devices, deployment manoeuvres (standard versus 'Push and Fluff' technique), proximal balloon guide catheter (PBGC), distal aspiration catheter (DAC) or both. The angiographic clot protrusion sign (ACPS) was recorded. Completed FPE (cFPE) was defined as a modified thrombolysis in cerebral infarction score of 2c-3. Associations were sought between cFPE and procedural approaches and angiographic signs.

RESULTS

A total of 193 patients were included. cFPE was achieved in 74 (38.3%) patients. The use of the push and fluff technique (odds ratio (OR) 3.45, 95% confidence interval (CI): 1.28-9.29, p = 0.010), PBGC (OR 3.81, 95% CI: 1.41-10.22, p = 0.008) and ACPS (OR 4.71, 95% CI: 1.78-12.44, p = 0.002) were independently associated with cFPE. Concurrence of these three variables led to cFPE in 82 vs 35% of the remaining cases (p = 0.002).

CONCLUSIONS

The concurrence of the PBGC, the push and fluff technique, and the ACPS was associated with the highest rates of cFPE. Appropriate selection of the thrombectomy device and deployment technique may lead to better procedural outcomes. ACPS could be used to assess clot integration strategies in future trials.

The Effects of Balloon-Guide Catheters on Outcomes after Mechanical Thrombectomy in Acute Ischemic Strokes : A Meta-Analysis

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.

Impact of Balloon-Guiding Catheter Location on Recanalization in Patients with Acute Stroke Treated by Mechanical Thrombectomy

BACKGROUND AND PURPOSE

Mechanical thrombectomy with proximal flow control and forced aspiration may improve the outcome of endovascular revascularization therapy for patients with acute stroke. The purpose of this study was to compare the impact of balloon-guiding catheter locations in patients treated for anterior circulation acute ischemic stroke using mechanical thrombectomy.

MATERIALS AND METHODS

The influence of the balloon-guiding catheter location (proximal, balloon-guiding catheter tip proximal to C1 vertebral body; distal, between the skull base and the C1 vertebral body) was analyzed in patients with acute anterior circulation stroke treated with stent-retriever thrombectomy. The baseline angiographic/clinical characteristics, time intervals, recanalization rates, and clinical outcomes were compared.

RESULTS

The clinical analysis included 102 patients (mean age, 69.5 ± 12.8 years; male/female ratio = 52:50). The balloon-guiding catheter was located distally in 49 patients and proximally in 53 patients for flow control and forced aspiration during stent retrieval. The puncture-to-recanalization time was shorter in the distal group than in the proximal group (40 versus 56 minutes, P = .02). Successful and complete recanalizations were more frequently achieved in the distal group compared with the proximal group (98.0% versus 75.5%. P = .003; 67.3% versus 45.3%, P = .04, respectively). Multivariate analysis showed that the distal catheterization location was independently associated with successful recanalization (adjusted OR, 13.4; 95% CI, 2.4-254.8; P = .02).

CONCLUSIONS

Location of the balloon-guiding catheter has a significant impact on recanalization in patients with acute stroke. The balloon-guiding catheter should be positioned as distally as safely possible in the cervical ICA for maximally effective thrombectomy.

Experience of the New FlowGate2 Device as a Balloon Guide Catheter for Ischemic Stroke Intervention

BACKGROUND

We report the experience of the FlowGate² (FG2) as a new balloon guide catheter in endovascular stroke intervention.

METHODS

We evaluated the various outcomes and complications of patients with intracranial large artery occlusion undergoing endovascular stroke intervention with FG2 at our center. Baseline characteristics (failure rate of device application, sex, age, risk factors, arterial occlusion sites, and time intervals) were reviewed. Outcomes were evaluated according to National Institutes of Health Stroke Scale score, modified Rankin Scale (mRS) score, number of stent passages required, and Thrombolysis in Cerebral Infarction score. The incidence of hemorrhage, vessel damage, distal emboli, and mortality rate were evaluated as indicators of complications.

RESULTS

Overall, 70 patients were enrolled, except the 2 patients with application failure of FG2. Seventy patients with a median age of 69 years were treated with FG2. Arterial occlusion involved the M1 (50%) and M2 (14.3%) segments, internal carotid artery (25.7%), and posterior circulation (10%). Median value of mRS at 90 days was 2.8, and 37 patients (52.8%) had a mRS score ≤2. The recanalization rate in patients with a Thrombolysis in Cerebral Infarction score of 2b or 3 was 91.4%. The hemorrhage rate was 5.7%, but none were symptomatic. In terms of complications, distal emboli occurred in 4.3% of cases.

CONCLUSIONS

Endovascular stroke intervention with the FG2 is safe and effective with good accessibility and less occurrence of distal emboli. Its trackability, stability, and luminal size make the FG2 suitable for stroke intervention.

First-line contact aspiration vs stent-retriever thrombectomy in acute ischemic stroke patients with large-artery occlusion in the anterior circulation: Systematic review and meta-analysis

BACKGROUND

In acute ischemic stroke patients with large-artery occlusion, uncertainties remain about whether clinically important outcomes are comparable between first-line contact aspiration and stent-retriever thrombectomy, although two trials have investigated whether one strategy should be preferred over another.

PURPOSE

The purpose of this article is to compare the efficacy and safety of first-line contact aspiration and stent-retriever thrombectomy in stroke patients with anterior circulation large-artery occlusion.

METHODS

We undertook a systematic review of studies of patients treated for large-artery occlusion, with the latest devices of either strategy, within six hours of stroke onset. We determined rates of final complete reperfusion (defined as modified Thrombolysis In Cerebral Infarction score = 3), periprocedural complications and 90-day functional independence (defined as modified Rankin Scale (mRS) score 0-2), and excellent outcome (defined as mRS score 0-1) after contact aspiration and after stent-retriever thrombectomy using random-effects meta-analyses. Any differential effects in rates between the two strategies were assessed using random-effects meta-regressions.

RESULTS

Fifteen studies (1817 patients) were included. There was no difference in rates of final complete reperfusion at the end of all endovascular procedures between contact aspiration and stent retrievers (51.1%, 95% confidence interval (CI) 39.3-62.9; vs 38.3%, 95% CI 28.6-48.0; p_int = 0.14), 90-day functional independence (45.0%, 40.7-49.2; vs 52.4%, 47.7-57.1; p_int = 0.45) and excellent outcome (32.1%, 25.7-38.5; vs 34.1%, 21.2-46.9; p_int = 0.94). Rates of periprocedural complications did not differ between the two strategies.

CONCLUSIONS

Current data suggest no difference in efficacy and safety between first-line contact aspiration and stent-retriever thrombectomy in stroke patients with large-artery occlusion.

Effect of balloon guide catheter on clinical outcomes and reperfusion in Trevo thrombectomy

Introduction

The Solitaire stent retriever registry showed improved reperfusion, faster procedure times, and better outcome in acute stroke patients with large vessel occlusion treated with a balloon guide catheter (BGC) and Solitaire stent retriever compared with a conventional guide catheter. The goal of this study was to evaluate whether use of a BGC with the Trevo stent retriever improves outcomes compared with a conventional guide catheter.

Methods

The TRACK registry recruited 23 sites to submit demographic, clinical, and site adjudicated angiographic and outcome data on consecutive patients treated with the Trevo stent retriever. BGC use was at the discretion of the physician.

Results

536 anterior circulation patients (of whom 279 (52.1%) had BGC placement) were included in this analysis. Baseline characteristics were notable for younger patients in the BGC group (65.4±15.3 vs 68.1±13.6, P=0.03) and lower rate of hypertension (72% vs 79%, P=0.06). Mean time from symptom onset to groin puncture was longer in the BGC group (357 vs 319 min, P=0.06).Thrombolysis in Cerebral Infarction 2b/3 scores were higher in the BGC cohort (84% vs 75.5%, P=0.01). There was no difference in reperfusion time, first pass effect, number of passes, or rescue therapy. Good clinical outcome at 3 months was superior in patients with BGC (57% vs 40%; P=0.0004) with a lower mortality rate (13% vs 23%, P=0.008). Multivariate analysis demonstrated that BGC use was an independent predictor of good clinical outcome (OR 2; 95% CI 1.3 to 3.1, P=0.001).

Conclusions

In acute stroke patients presenting with anterior circulation large vessel occlusion, use of a BGC with the Trevo stent retriever resulted in improved reperfusion, improved clinical outcome, and lower mortality.