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

Comparison of balloon guide catheter versus non-balloon guide catheter for mechanical thrombectomy in patients with distal medium vessel occlusion

BACKGROUND

Several studies have established the safety and efficacy of balloon guide catheters (BGCs) for large vessel occlusions. However, the utility of BGCs remains largely unexplored for distal medium vessel occlusions (DMVOs). In this study, we aim to compare the outcomes of BGC vs. Non-BGC in patients undergoing mechanical thrombectomy (MT) for DMVO.

METHOD

This retrospective study from the Stroke Thrombectomy and Aneurysm Registry (STAR) encompassed adult patients with acute anterior cerebral artery, posterior cerebral artery, and middle cerebral artery-M2-3-4 occlusions. Procedure times, safety, recanalization, and neurological outcomes were compared between the two groups, with subgroup analysis based on first-line thrombectomy techniques.

RESULTS

A total of 1508 patients were included, with 231 patients (15.3%) in the BGC group and 1277 patients (84.7%) in the non-BGC group. The BGC group had a lower modified Thrombolysis in Cerebral Infarction (mTICI) score ≥2C (43.2% vs 52.7%, P=0.01), longer time from puncture to intracranial access (15 vs 8 min, P<0.01), and from puncture to final recanalization (97 vs 34 min, P<0.01). In the Solumbra subgroup, the first pass effect (FPE) rate was lower in the BGC group (17.4% vs 30.7%, P=0.03). Regarding clinical outcomes, the BGC group had a lower rate of distal embolization (8.8% vs 14.9%, P=0.03).

CONCLUSION

Our study found that use of BGC in patients with DMVO was associated with lower mTICI scores, decreased FPE rates, reduced distal embolization, and longer procedure times.

Comparison of Balloon Guide Catheters and Standard Guide Catheters for Acute Ischemic Stroke: An Updated Systematic Review and Meta-analysis

OBJECTIVE

The objective of this study was to update our 2021 systematic review and meta-analysis which reported that balloon guide catheters (BGC) are associated with superior clinical and angiographic outcomes compared to standard guide catheters for treatment of acute ischemic stroke.

METHODS

We conducted a systematic review of 7 electronic databases to identify literature published between January 2010 and September 2023 reporting BGC versus non-BGC approaches. Primary outcomes were final modified thrombolysis in cerebral infarction (mTICI) ≥2b, first-pass effect (mTICI ≥2c on first pass), and modified Rankin scale 0-2 at 90 days. The risk of bias was assessed using the Newcastle Ottawa Scale. A separate random effects model was fitted for each outcome. Subgroup analyses by first-line approach were conducted.

RESULTS

Twenty-four studies comprising 8583 patients were included (4948 BGC; 3635 non-BGC; 1561 BGC + Stent-retriever; 1297 non-BGC + Stent-retriever). Nine studies had low risk of bias, 3 were moderate risk, and 12 were high risk. Patients treated with BGCs had higher odds of achieving mTICI 2b/3, first-pass effect mTICI 2c/3, and modified Rankin scale 0-2 at 90 days (P < 0.001). The number of patients needed to treat in order to achieve one additional successful recanalization is 17. BGC + Stent-retriever was associated with higher odds of mTICI≥2b, 90-day modified Rankin scale 0-2, and reduced odds of 90-day mortality compared to non-BGC + Stent-retrievers. The main limitation was the absence of randomized trials.

CONCLUSIONS

These findings corroborate our previous results suggesting that MT using BGCs is associated with better safety and effectiveness outcomes for acute ischemic stroke, especially BGC + Stent-retrievers.

Comparison of Clinical and Radiological Outcomes Between Different (Balloon) Guide Catheter With and Without Inflated Balloon in Acute Ischemic Stroke Patients: A MaSQ-Registry Study

PURPOSE

Balloon guide catheters (BGCs) are used in endovascular treatment (EVT) for ischemic stroke. Previous literature did not distinguish between BGC use with and without inflated balloon. This study aims to compare outcomes between non-BCG and BGC use with and without inflated balloon during EVT.

METHODS

Patients who underwent EVT for anterior circulation ischemic stroke between September 2020 and February 2023 were analyzed. Patients were divided into three groups: non-BGC, BGC with inflated balloon, or BGC without inflated balloon. The primary outcome was the ordinal modified Rankin Scale (mRS) at 90-day follow-up. Secondary outcomes included expanded Thrombolysis In Cerebral Ischemia score (eTICI) and periprocedural complications. Regression analyses with BGC with inflated balloon as comparator were performed with adjustments. Subgroup analyses were conducted based on first-line thrombectomy technique.

RESULTS

Out of 511 patients, 428 patients were included. Compared to BCG with inflated balloon, the mRS at 90 days did not differ in the group without inflated balloon (adjusted common [ac]OR: 1.07, 95%CI 0.67-1.73) or non-BGC (acOR: 1.42, 95%CI 0.83-2.42). Compared to patients treated with a BGC with inflated balloon, those treated with BGC without inflated balloon had lower eTICI scores (acOR: 0.59, 95%CI 0.37-0.94), and patients treated with non-BGC had lower chances of periprocedural complications (aOR: 0.41, 95%CI 0.20-0.86).

CONCLUSIONS

This study shows no clinical differences in ischemic stroke patients treated with BGC with inflated balloon compared to non-BGC and BGC without inflated balloon, despite lower periprocedural complication rates in the non-BGC group and lower eTICI scores in the BGC without inflated balloon group.

LEVEL OF EVIDENCE

Level 3, non-controlled retrospective cohort study.

Combined Aspiration and Stent Retriever Thrombectomy for Distal Carotid Artery Occlusion Using Balloon Guide versus Non-Balloon Guide Catheter

Background: The introduction of endovascular thrombectomy dramatically changed acute stroke management and became the standard treatment. Balloon guide catheters provide flow arrest during the clot retrieval process and have several advantages.This study aimed to compare balloon guide catheters (BGCs) versus non-balloon guide catheters (NBGCs) as a part of a combined treatment modality in patients presenting with acute ischemic stroke. Methods: This retrospective study included n = 65 patients who underwent a combined endovascular stroke treatment for distal internal carotid artery (ICA) occlusion. Patients underwent aspiration and stent retriever thrombectomy with the use of BGCs (Group 1, n = 27) or NBGCs (Group 2, n = 38). Results: The groups were compared for outcomes: the National Institutes of Health Stroke Scale (NIHSSS) score change, successful recanalization, good functional outcome at three months, and in-hospital mortality. Conclusion: The two groups didn't differ in terms of the NIHSS score change compared to baseline (p > 0.05). Moreover, there were no significant differences between the two groups in terms of the successful recanalization rate, three-month favorable functional outcome rate, and in-hospital mortality (p = 0.292, p = 0.952, p = 0.178), respectively. Further prospective studies with a larger number of patients and better methodology are warranted.

Flow reversal during stroke thrombectomy

When performing mechanical thrombectomy for stroke patients, some physicians use balloon guide catheters (BGCs) in order to achieve flow reversal and thereby improve reperfusion quality. There is substantial evidence favoring the use of BGCs to improve reperfusion rates and clinical outcomes for thrombectomy patients; however, as we will outline in this review, there is also evidence that BGCs do not achieve reliable flow reversal in many circumstances. Therefore, if we are able to modify our techniques to improve the likelihood of flow reversal during thrombectomy maneuvers, we may be able to further improve reperfusion quality and clinical outcomes. This paper provides an overview of concepts on this topic and outlines some potential techniques to facilitate flow reversal more consistently, including a method to visually confirm it, with the aim of making iterative improvements towards optimal reperfusion for stroke patients.

Effect of Bridging Thrombolysis on the Efficacy of Stent Retriever Thrombectomy Techniques : Insights from the SWIFT-DIRECT trial

BACKGROUND

There are little available data regarding the influence of intravenous thrombolysis (IVT) on the efficacy of different first line endovascular treatment (EVT) techniques.

METHODS

We used the dataset of the SWIFT-DIRECT trial which randomized 408 patients to IVT + EVT or EVT alone at 48 international sites. The protocol required the use of a stent retriever (SR), but concomitant use of a balloon guide catheter (BGC) and/or distal aspiration (DA) catheter was left to the discretion of the operators. Four first line techniques were applied in the study population: SR, SR + BGC, SR + DA, SR + DA + BGC. To assess whether the effect of allocation to IVT + EVT versus EVT alone was modified by the first line technique, interaction models were fitted for predefined outcomes. The primary outcome was first pass mTICI 2c‑3 reperfusion (FPR).

RESULTS

This study included 385 patients of whom 172 were treated with SR + DA, 121 with SR + DA + BGC, 57 with SR + BGC and 35 with SR. There was no evidence that the effect of IVT + EVT versus EVT alone would be modified by the choice of first line technique; however, allocation to IVT + EVT increased the odds of FPR by a factor of 1.68 (95% confidence interval, CI 1.11-2.54).

CONCLUSION

This post hoc analysis does not suggest treatment effect heterogeneity of IVT + EVT vs EVT alone in different stent retriever techniques but provides evidence for increased FPR if bridging IVT is administered before stent retriever thrombectomy.

BOBBY balloon guide catheter thrombectomy in large-vessel occlusion stroke: Initial experience

BACKGROUND AND PURPOSE

Nonrandomized studies have found Balloon Guide Catheter (BGC) use to improve technical and functional outcomes in patients undergoing mechanical thrombectomy (MT).

MATERIALS AND METHODS

We performed a retrospective analysis on prospectively collected data of consecutive ischemic stroke patients undergoing MT at our institution (December 2020-October 2021). Interventions where BOBBY BGC (BBGC, MicroVentionTM, Aliso Viejo, CA) was used were identified. Baseline demographics and clinico-radiographic characteristics were retrospectively collected and analysed using descriptive statistics.

RESULTS

A total of 43 patients received BBGC-MT (male: female = 26:17, median age 72 years [IQR 62-82]). The most common occlusion site was the middle cerebral artery (MCA) (60.4%). Over half (51.2%) received intravenous thrombolytics. The BBGC tracked well over tortuous aortic arches (type II 34.8%, type III 16.3%), with median arteriotomy-to-perfusion time of 29 min (IQR 20-46). Thromboaspiration was used as first-line MT technique in 69.7% cases, with 1 (IQR 1-2) median MT pass achieving modified TICI (thrombolysis in cerebral ischemia) scores of 3 and 2b/3 in 74.4% and 95.3% respectively. Our overall first pass effect (FPE, defined as mTICI 3 after firs-pass) and modified FPE (defined as, mTICI 2b/3 after first-pass) rates were 51.1% and 79.1% respectively, with rates of 92.3% and 100% respectively when stentretriever and thromboaspiration were combined. The median reduction in National Institutes of Health Stroke Scale (NIHSS) was 9 (IQR 4-15, p < 0.0001), with a median 90-day modified Rankin Score (mRS) of 1.5 (IQR 0-2).

CONCLUSIONS

BOBBY BGC use resulted in a high first-pass effect rate and may contribute towards improved functional outcomes.

Pre-navigation balloon technique: Distal emboli protection during stent retriever thrombectomy

OBJECTIVE

During stent retriever thrombectomy, a balloon guide catheter reduces distal emboli and consequently improves clinical outcomes. Because balloons are usually used before stent retrieval, these can affect the thrombus including the distal emboli while performing microcatheter navigation. This study aimed to evaluate the usefulness and safety of the pre-navigation balloon technique during microcatheter and microwire navigation.

METHODS

Patients who underwent stent retriever thrombectomy secondary to an anterior circulation large-artery occlusion were retrospectively evaluated. The pre-navigation balloon technique was used, and the number of retrievals, procedure time, final recanalization, presence of distal emboli, first-pass effect (FPE), symptomatic intracranial hemorrhage including procedure-related complications, and clinical outcomes at 3 months were evaluated.

RESULTS

In total 123 patients were analyzed, and occurrence of distal emboli was lesser in the pre-navigation balloon than in the non-preballoon group (4.4% vs. 11.5%, p = 0.02). No statistical difference was found in successful recanalization, mortality, and procedure-related complications. Moreover, the pre-navigation balloon group had a higher FPE than the non-balloon group (37.8% vs. 20.5%, p = 0.004). Although no statistical difference was found in the pre-navigation balloon group, a trend toward a higher rate of good clinical outcomes was observed (mRS 0-2 at 3 months, 55.6% vs. 48.7%, p = 0.09). For ICA occlusion(n = 35), significant effects were seen in decreasing distal embolism (0(0%) vs 3(16%), p = 0.01), increasing FPE (8(50%) vs 6(32%), p = 0.003), and improving clinical outcomes (mRS 0-2 at 3 months, 9(56%) vs 7(37%), p = 0.03) in the pre-navigation balloon group. In the multivariate analysis, lesser distal embolism (0.91 [0.80-1.00], p = 0.02), higher successful recanalization (3.52 [1.11-7.03], p = 0.016), and higher FPE (3.17 [1.83-7.37], p = 0.001) secondary to the procedure was a predictor of favorable clinical outcomes.

CONCLUSIONS

The pre-navigation balloon technique significantly reduced occurrence of distal embolism and increased the FPE.

Impact of Balloon Guide Catheters in Elderly Patients Treated with Mechanical Thrombectomy: Insights from the ROSSETTI Registry

BACKGROUND AND PURPOSE

Several nonrandomized studies have demonstrated the effectiveness of balloon guide catheters in treating patients with anterior circulation large-vessel occlusion. However, their impact on the elderly populations has been underreported. We aimed to analyze the effect of balloon guide catheters in a cohort of elderly patients (80 years of age or older) with anterior circulation large-vessel occlusion.

MATERIALS AND METHODS

Consecutive patients from June 2019 to June 2022 were collected from the ROSSETTI Registry. Demographic and clinical data, angiographic endovascular technique, and clinical outcome were compared between balloon guide catheter and non-balloon guide catheter groups. We studied the association between balloon guide catheters and the rate of complete recanalization after a single first-pass effect modified TICI 2c-3, as well as their association with functional independence at 3 months.

RESULTS

A total of 808 patients were included during this period, 465 (57.5%) of whom were treated with balloon guide catheters. Patients treated with balloon guide catheters were older, had more neurologic severity at admission and lower baseline ASPECTS, and were less likely to receive IV fibrinolytics. No differences were observed in terms of the modified first-pass effect between groups (45.8 versus 39.9%, P = .096). In the multivariable regression analysis, balloon guide catheter use was not independently associated with a modified first-pass effect or the final modified TICI 2c-3, or with functional independence at 3 months.

CONCLUSIONS

In our study, balloon guide catheter use during endovascular treatment of anterior circulation large-vessel occlusion in elderly patients did not predict the first-pass effect, near-complete final recanalization, or functional independence at 3 months. Further studies, including randomized clinical trials, are needed to confirm these results.

Estimating the impact of balloon guide catheter with mechanical thrombectomy for acute ischemic stroke: A U.S. cost analysis

BACKGROUND

Balloon guide catheters (BGCs) can be used adjunctively during mechanical thrombectomy (MT) for acute ischemic stroke (AIS). Evaluating the potential economic impact associated with adjunctive BGC use is an important consideration for resource allocation.

METHODS

Decision tree models were used to estimate the economic value of BGC use in MT through its impact on functional outcomes. Healthcare utilization cost estimates in the short- and long-term for patients with different 90-day mRS scores were analyzed for MT-only and MT + BGC scenarios. Deterministic (one-way) and probabilistic sensitivity analyses were performed to evaluate the robustness and uncertainty of model parameters.

RESULTS

Per-patient index hospitalization cost was estimated at $65,260 for MT-only and $62,883 for MT + BGC scenarios. Per-patient one-year post-index hospitalization cost was estimated at $27,569 for MT-only and $24,830 for MT + BGC. MT + BGC had a total cost savings of $5117 compared with MT-only. Deterministic (one-way) sensitivity analysis demonstrated that cost saving per patient was most sensitive to the proportion of patients in the mRS 0-2 category in both MT + BGC and MT-only. In a probabilistic sensitivity analysis, mean per-patient costs for the index hospitalization were estimated at $63,737 for MT-only and $61,425 for MT + BGC. Mean per-patient cost estimates one-year post-index hospitalization was $27,445 for MT-only and $24,715 for MT + BGC. MT + BGC had a total cost savings of $5043 compared with MT-only.

CONCLUSION

Mechanical thrombectomy with adjunctive BGC use may reduce short-term and long-term patient costs due to improved functional outcomes when compared to MT treatment alone for AIS.

Balloon Gliding Technique: A novel use of balloon guiding catheters in accessing challenging circulations when treating acute ischemic stroke

BACKGROUND

Challenging arterial anatomy delays, or prevents timely endovascular treatment (EVT) of acute ischemic stroke (AIS). We introduce a new technique called 'Balloon Gliding Technique (BGT)' to overcome difficult arterial anatomy during EVT of AIS, utilizing flow-assistance to access challenging circulations.

METHODS

Retrospective review of a prospectively collected database of all patients presenting to a single institution with AIS who underwent EVT was performed from January 2021 to June 2021. Patients in whom BGT was performed were assessed. BGT consists of advancing the balloon guide catheter in the cervical carotid artery while its balloon is inflated, and therefore carried by downstream flow.

RESULTS

Of 51 patients presenting with AIS secondary to large vessel occlusion during the study period, five patients underwent BGT. All five patients had anterior circulation large vessel occlusions. Mean age of the BGT patients was 92.2 years, and all patients were females. A type 3 arch was present in all patients. BGT was performed in all cases following initial failure of conventional techniques to cannulate the target circulation. BGT was successful in achieving distal cervical carotid access in 4 out of the 5 patients in whom BGT was attempted. Successful recanalization (modified treatment in cerebral ischemia 2b-3) was obtained in all cases with no complications.

CONCLUSIONS

Balloon Gliding Technique (BGT) is a safe technique that can safely overcome challenging anatomy during endovascular treatment of acute ischemic stroke. Further studies can assist in demonstrating both its safety and effectiveness.

Combined balloon guide catheter, aspiration catheter, and stent retriever technique versus balloon guide catheter and stent retriever alone technique: a systematic review and meta-analysis

BACKGROUND

The use of a combination of balloon guide catheter (BGC), aspiration catheter, and stent retriever in acute ischemic stroke thrombectomy has not been shown to be better than a stent retriever and BGC alone, but this may be due to a lack of power in these studies. We therefore performed a meta-analysis on this subject.

METHODS

A systematic literature search was performed on PubMed, Scopus, Embase/Ovid, and the Cochrane Library from inception to October 20, 2021. Our primary outcomes were the rate of successful final reperfusion (Treatment in Cerebral Ischemia (TICI) 2c-3) and first pass effect (FPE, defined as TICI 2c-3 in a single pass). Secondary outcomes were 3 month functional independence (modified Rankin Scale score of 0-2), mortality, procedural complications, embolic complications, and symptomatic intracranial hemorrhage (SICH). A meta-analysis was performed using RevMan 5,4, and heterogeneity was assessed using the I² test.

RESULTS

Of 1629 studies identified, five articles with 2091 patients were included. For the primary outcomes, FPE (44.9% vs 45.4%, OR 1.04 (95% CI 0.90 to 1.22), I²=57%) or final successful reperfusion (64.5% vs 68.6%, OR 0.98 (95% CI 0.81% to 1.20%), I²=85%) was similar between the combination technique and stent retriever only groups. However, the combination technique had significantly less rescue treatment (18.8% vs 26.9%; OR 0.70 (95% CI 0.54 to 0.91), I²=0%). This did not translate into significant differences in secondary outcomes in functional outcomes, mortality, emboli, complications, or SICH.

CONCLUSION

There was no significant difference in successful reperfusion and FPE between the combined techniques and the stent retriever and BGC alone groups. Neither was there any difference in functional outcomes, complications, or mortality.

Neuroimaging of Acute Ischemic Stroke: Multimodal Imaging Approach for Acute Endovascular Therapy

Advances in acute ischemic stroke (AIS) treatment have been contingent on innovations in neuroimaging. Neuroimaging plays a pivotal role in the diagnosis and prognosis of ischemic stroke and large vessel occlusion, enabling triage decisions in the emergent care of the stroke patient. Current imaging protocols for acute stroke are dependent on the available resources and clinicians' preferences and experiences. In addition, differential application of neuroimaging in medical decision-making, and the rapidly growing evidence to support varying paradigms have outpaced guideline-based recommendations for selecting patients to receive intravenous or endovascular treatment. In this review, we aimed to discuss the various imaging modalities and approaches used in the diagnosis and treatment of AIS.

Comparing the Conventional and Balloon-Guided Catheter-Assisted SWIM Technology for the Treatment of Acute Ischemic Stroke

Objective

Acute ischemic stroke is common in elder patients. This study investigates whether using the balloon-guided catheter (BGC) would improve the effect of stent thrombectomy (Solitaire FR With Intracranial Support Catheter for Mechanical Thrombectomy, SWIM) for patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO).

Method

The data of 209 patients with AIS-LVO underwent SWIM were collected retrospectively from January 2017 to June 2021. These patients were divided into two groups based on whether they used of BGC or not. The propensity score matching (PSM) analysis was used to compare the differences in the first pass effect (FPE), successful recanalization, embolus escape rate, symptomatic intracranial hemorrhage (sICH), 90-day clinical favorable outcome, 90-day all-cause mortality, and complications in the patients treated with SWIM combined with balloon-guided catheter or conventional catheter.

Results

Among the 209 patients, 44 patients were treated with BGC and 165 patients were not. After matching, a total of 111 patients were included. The results showed that there was no statistical difference in FPE (35.1% in non-BGC group compared to 24.3% in BGC group, matched RR, 0.59; 95% CI, 0.24–1.44), successful recanalization (89.2 vs. 91.9%, matched RR, 1.37; 95%CI, 0.34–5.51), embolus escape (6.8 vs. 8.1%, matched RR, 1.22; 95%CI, 0.28–5.40), sICH (8.1 vs. 13.5%; matched RR, 1.77; 95%CI 0.50–6.24), 90-day clinical favorable outcome (48.7 vs. 54.1%, matched RR, 1.11; 95%CI 0.51–2.46), 90-day all-cause mortality (17.6 vs. 21.6%, matched RR, 1.29; 95%CI 0.48–3.47), and the incidence of complications (6.8 vs. 5.4%, matched RR, 0.79 95%CI 0.15–4.27). These results indicate that using SWIM as the first-line treatment for patients with AIS-LVO, there is no statistical significance in FPE, final successful recanalization, distal emboli, sICH, procedural time, 90-day favorable outcome, 90-day mortality, and complications with or without BGC.

Conclusion

Balloon-guided catheter does not affect the result of using SWIM as the first-line treatment for patients with AIS-LVO. Our results will guide daily practice, with the adoption of the use of a guided catheter without a balloon.

Endovascular Transcarotid Artery Revascularization Using the Walrus Balloon Guide Catheter: Preliminary Experience

BACKGROUND

The Walrus Balloon Guided System Catheter is a new generation of balloon guide catheter (BGC) designed to bypass some technical limitations of conventional BGC devices. Their utility in cervical carotid disease treatment has not been reported. We report our preliminary experience in cervical carotid treatment using the Walrus BGC to perform a modified endovascular transcarotid artery revascularization technique.

METHODS

Patients with cervical carotid disease undergoing endovascular treatment using the Walrus BGC at our institution were identified. The pertinent baseline demographics and procedural outcomes were collected and analyzed.

RESULTS

Twelve patients were included (median age, 70; 58.3% females). All patients had an imaging-confirmed cervical carotid disease that indicated intervention: 6 with high-grade cervical arteriosclerotic carotid stenosis, 2 with intraluminal thrombi, 1 with traumatic carotid dissection, and 3 patients with cervical carotid tandem occlusion along with acute ischemic stroke secondary to large vessel occlusion that required mechanical thrombectomy. Carotid artery stenting was performed in all cases, except 2 of the 3 mechanical thrombectomy cases (angioplasty only). All patients had at least periprocedural follow-up of 30 days, with no stroke, myocardial infarction, or death encountered.

CONCLUSIONS

We describe a modified endovascular transcarotid artery revascularization technique. We used a standard femoral access to navigate the Walrus catheter in the common carotid artery, followed by balloon inflation for proximal flow arrest or flow reversal (when connected to the aspiration pump) to deploy the carotid stent across the stenosis, while avoiding distal external carotid artery balloon occlusion. Successful treatment was achieved in all cases, with no periprocedural complications encountered.

Carotid artery revascularization using the Walrus balloon guide catheter: safety and feasibility from a US multicenter experience

INTRODUCTION

The Walrus balloon guide catheter (BGC) is a new generation of BGC, designed to eliminate conventional limitations during mechanical thrombectomy.

OBJECTIVE

To report a multi-institutional experience using this BGC for proximal flow control (PFC) in the setting of carotid artery angioplasty/stenting (CAS) in elective (eCAS) and tandem strokes (tCAS).

METHODS

Prospectively maintained databases at 8 North American centers were queried to identify patients with cervical carotid disease undergoing eCAS/tCAS with a Walrus BGC.

RESULTS

110 patients (median age 68, 64.6% male), 80 (72.7%) undergoing eCAS and 30 (27.3%) tCAS procedures, were included (median cervical carotid stenosis 90%; 46 (41.8%) with contralateral stenosis). Using a proximal flow-arrest technique in 95 (87.2%) and flow-reversal in 14 (12.8%) procedures, the Walrus was navigated into the common carotid artery successfully in all cases despite challenging arch anatomy (31, 28.2%), with preferred femoral access (103, 93.6%) and in monitored anesthesia care (90, 81.8%). Angioplasty and distal embolic protection devices (EPDs) were used in 91 (83.7%) and 58 (52.7%) procedures, respectively. tCAS led to a modified Thrombolysis in Cerebral Infarction 2b/3 in all cases. Periprocedural ischemic stroke (up to 30 days postoperatively) rate was 0.9% (n=1) and remote complications occurred in 2 (1.8%) cases. Last follow-up modified Rankin Scale score of 0-2 was seen in 95.3% of eCAS cohort, with no differences in complications in the eCAS subgroup between PFC only versus PFC and distal EPD (median follow-up 4.1 months).

CONCLUSION

Walrus BGC for proximal flow control is safe and effective during eCAS and tCAS. Procedural success was achieved in all cases, with favorable safety and functional outcomes on short-term follow-up.

Evidence-Based Updates to Thrombectomy: Targets, New Techniques, and Devices

Endovascular thrombectomy (EVT) has been validated in several randomized controlled trials in recent years for its efficacy in the treatment of acute ischemic strokes (AIS) and is now the standard of care according to international guidelines. However, in about 20% of EVT procedures, recanalization is not achieved, and over 50% of patients who undergo EVT still do not have good functional outcome. In this article, we provide an extensive review of the latest evidence and developments in the field of EVT, with particular focus on the factors that improve patient outcomes. These factors include new and adjunctive techniques such as combination of direct aspiration and stent retriever, intra-arterial urokinase or 2b/3a inhibitors, rescue stenting, as well as novel devices including balloon guide catheters and the newer generations of aspiration catheters and stent retrievers. We also examined the latest notion of using first-pass effect (FPE) as the target to achieve during EVT, which has been associated with an improved functional outcome. While the field of EVT has been rapidly evolving, further research is required in specific AIS patient populations such as those with large ischemic core, late presentation beyond 24 h, posterior circulation strokes, and with distal medium vessel occlusion or tandem lesions to better assess its efficacy and safety.

Addition of intracranial aspiration to balloon guide catheter does not improve outcomes in large vessel occlusion anterior circulation stent retriever based thrombectomy for acute stroke

BACKGROUND

Balloon guide catheter (BGC) in stent retriever based thrombectomy (BGC+SR) for patients with large vessel occlusion strokes (LVOS) improves outcomes. It is conceivable that the addition of a large bore distal access catheter (DAC) to BGC+SR leads to higher efficacy. We aimed to investigate whether the combined BGC+DAC+SR approach improves angiographic and clinical outcomes compared with BGC+SR alone for thrombectomy in anterior circulation LVOS.

METHODS

Consecutive patients with anterior circulation LVOS from June 2019 to November 2020 were recruited from the ROSSETTI registry. Demographic, clinical, angiographic, and outcome data were compared between patients treated with BGC+SR alone versus BGC+DAC+SR. The primary outcome was first pass effect (FPE) rate, defined as near complete/complete revascularization (modified Thrombolysis in Cerebral Infarction (mTICI) 2c-3) after single device pass.

RESULTS

We included 401 patients (BGC+SR alone, 273 (66.6%) patients). Patients treated with BGC+SR alone were older (median age 79 (IQR 68-85) vs 73.5 (65-82) years; p=0.033) and had shorter procedural times (puncture to revascularization 24 (14-46) vs 37 (24.5-63.5) min, p<0.001) than the BGC+DAC+SR group. Both approaches had a similar FPE rate (52% in BGC+SR alone vs 46.9% in BGC+DAC+SR, p=0.337). Although the BGC+SR alone group showed higher rates for final successful reperfusion (mTICI ≥2b (86.8% vs 74.2%, p=0.002) and excellent reperfusion, mTICI ≥2 c (76.2% vs 55.5%, p<0.001)), there were no significant differences in 24 hour National Institutes of Health Stroke Scale score or rates of good functional outcome (modified Rankin Scale score of 0-2) at 3 months across these techniques.

CONCLUSIONS

Our data showed that addition of distal intracranial aspiration catheters to BGC+SR based thrombectomy in patients with acute anterior circulation LVO did not provide higher rates of FPE or improved clinical outcomes.

Clinical and Procedural Outcomes with or without Balloon Guide Catheters during Endovascular Thrombectomy in Acute Ischemic Stroke: A Systematic Review and Meta-analysis with First-line Technique Subgroup Analysis

BACKGROUND

Balloon guide catheters are increasingly used to improve clot retrieval by temporarily stopping proximal blood flow during endovascular thrombectomy.

PURPOSE

Our aim was to provide a summary of the literature comparing the procedural and clinical outcomes of endovascular thrombectomy with or without balloon guide catheters, depending on the first-line technique used.

DATA SOURCES

We used PubMed/MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews.

STUDY SELECTION

We chose studies that compared using balloon guide catheters with not using them.

DATA ANALYSIS

Random effects meta-analysis was performed to compare the procedural outcomes measured as the first-pass effect, successful reperfusion, number of passes, procedural duration, arterial puncture to reperfusion time, distal emboli, and clinical outcomes.

DATA SYNTHESIS

Overall, a meta-analysis of 16 studies (5507 patients, 50.8% treated with balloon guide catheters and 49.2% without them) shows that the use of balloon guide catheters increases the odds of achieving a first-pass effect (OR = 1.92; 95% CI, 1.34-2.76; P < .001), successful reperfusion (OR = 1.85; 95% CI, 1.42-2.40; P < .001), and good functional outcome (OR =1.48; 95% CI, 1.27-1.73; P < .001). Balloon guide catheters reduce the number of passes (mean difference = -0.35; 95% CI, -0.65 to -0.04; P = .02), procedural time (mean difference = -19.73; 95% CI, -34.63 to -4.83; P = .009), incidence of distal or new territory emboli (OR = 0.5; 95% CI, 0.26-0.98; P = .04), and mortality (OR = 0.72; 95% CI, 0.62-0.85; P < .001). Similar benefits of balloon guide catheters are observed when the first-line technique was a stent retriever or contact aspiration, but not for a combined approach.

LIMITATIONS

The analysis was based on nonrandomized trials with a moderate risk of bias.

CONCLUSIONS

Current literature suggests improved clinical and procedural outcomes associated with the use of balloon guide catheters during endovascular thrombectomy, especially when using the first-line stent retriever.

Balloon guide catheters: use, reject, or randomize?

Thrombectomy devices played an important role in the success of endovascular treatment trials over the past five years. A balloon guide catheter (BGC) is an adjunctive device used to arrest and reverse flow by inflating the balloon at its tip, which allows for flow reversal in intracranial arteries during retrieval of thrombectomy devices by applying concomitant aspiration through its lumen. Thereby, it can decrease the risk of clot fragmentation and distal embolization. Despite the numerous benchtop and clinical observational studies showing the superiority of BGC to conventional guide catheters in improving reperfusion quality and clinical outcome, its use is still low in clinical practice. The reasons behind this reluctance might be related to technical and cost issues. Therefore, high level evidence data, i.e., a randomized clinical trial, are needed to increase its implementation in thrombectomy procedures. Nonetheless, several obstacles and challenges can prevent the completion of such a trial, and efforts are needed to overcome them. We provide an overview of the current opinions about BGCs in the neurointerventional community and discuss the feasibility and challenges of a possible randomized trial to answer the question "should a BGC be routinely used in endovascular treatment of acute ischemic stroke?"

Comparison of Balloon Guide Catheters and Standard Guide Catheters for Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

Balloon guide catheters (BGCs) are designed to induce flow arrest during mechanical thrombectomy procedures for acute ischemic stroke due to large-vessel occlusion and have been associated with improved clinical and angiographic outcomes. We conducted a systematic review and meta-analysis evaluating the relative technical and clinical outcomes associated with BGC versus non-BGC approaches.

METHODS

A systematic review of clinical literature using the PubMed database was undertaken to identify multiarm studies published between 2010 and 2021 reporting the use of BGC versus non-BGC approaches for stroke treatment. Data collected included complete recanalization (thrombolysis in cerebral infarction, TICI), first-pass effect TICI 3, puncture-to recanalization time, number of endovascular attempts, distal embolization, symptomatic intracerebral hemorrhage, 90-day modified Rankin Scale score 0-2, and 90-day mortality. Subgroup analyses assessed the impact of treatment device (stent-retrievers, contact aspiration, combination therapy, and not specified/other). A random effects model was fit for each outcome measure.

RESULTS

Fifteen studies were included. Compared with non-BGC approaches, patients treated with BGCs had greater odds of TICI 3 (odds ratio [OR] 1.57; 95% confidence interval [95% CI] 1.08-2.29) and first-pass effect TICI 3 (OR 3.63; 95% CI 2.34-5.62), reduced puncture-to-revascularization time (mean difference -7.8; 95% CI -13.3 to -2.2), fewer endovascular attempts (mean difference -0.47; 95% CI -0.68 to -0.26), reduced odds of distal emboli (OR 0.34; 95% CI 0.17-0.71) and symptomatic intracerebral hemorrhage (OR 0.66; 95% CI 0.51-0.86), greater odds of 90-day modified Rankin Scale score 0-2 (OR 1.51; 95% CI 1.27-1.79), and reduced odds of mortality (OR 0.69; 95% CI 0.57-0.82).

CONCLUSIONS

BGCs yield superior technical and clinical outcomes while reducing patient complications.

Clinical impact of the first pass effect on clinical outcomes in patients with near or complete recanalization during mechanical thrombectomy for large vessel ischemic stroke

BACKGROUND AND PURPOSE

The first pass effect has been reported as a mechanical thrombectomy (MT) success metric in patients with large vessel occlusive stroke. We aimed to compare the clinical and neuroimagign outcomes of patients who had favorable recanalization (mTICI 2c or mTICI 3) achieved in one pass versus those requiring multiple passes.

METHODS

In this "real-world" multicenter study, patients with mTICI 2c or 3 recanalization were identified from three prospectively collected stroke databases from January 2016 to December 2019. Clinical outcomes were a favorable functional outcome at 90 days (modified Rankin Scale score 0-2), and the rate of symptomatic intracranial hemorrhage (ICH) any ICH, and 90-day mortality.

RESULTS

Favorable recanalization was achieved in 390/664 (59%) of consecutive patients who underwent MT (age 71.2 ± 13.2 years, 188 [48.2%] women). This was achieved after a single thrombectomy pass (n = 290) or multiple thrombectomy passes (n = 100). The rate of favorable clinical outcome was higher (41% vs. 28 %, p = .02) in the first pass group with a continued trend on multivariate analysis that did not reaching statistical significance (OR 1.68 95% confidence interval [CI] 1.0-2.95, p = .07). Similarly, the odds of any ICH were significantly lower (OR 0.56 CI 0.32-0.97, p = .03). A similar trend of favorable clinical outcomes was noticed on subgroup analysis of patients with M1 occlusion (OR 1.81 CI 1.01-3.61, p = .08).

CONCLUSION

The first-pass reperfusion was associated with a trend toward favorable clinical outcome and lower rates of ICH. These data suggest that the first-pass effect should be the mechanical thrombectomy procedure goal.

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.

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.

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.

The Next Step in the Treatment of Stroke

Although many patients do not receive reperfusion therapy because of delayed presentation and/or severity and location of infarct, new reperfusion approaches are expanding the window of intervention. Novel application of neuroprotective agents in combination with the latest methods of reperfusion provide a path to improved stroke intervention outcomes. We examine why neuroprotective agents have failed to translate to the clinic and provide suggestions for new approaches. New developments in recanalization therapy in combination with therapeutics evaluated in parallel animal models of disease will allow for novel, intra-arterial deployment of therapeutic agents over a vastly expanded therapeutic time window and with greater likelihood success. Although the field of neuronal, endothelial, and glial protective therapies has seen numerous large trials, the application of therapies in the context of newly developed reperfusion strategies is still in its infancy. Given modern imaging developments, evaluation of the penumbra will likely play a larger role in the evolving management of stroke. Increasingly more patients will be screened with neuroimaging to identify patients with adequate collateral blood supply allowing for delayed rescue of the penumbra. These patients will be ideal candidates for therapies such as reperfusion dependent therapeutic agents that pair optimally with cutting-edge reperfusion techniques.

Systematic review and meta-analysis of current rates of first pass effect by thrombectomy technique and associations with clinical outcomes

BACKGROUND

First pass effect (FPE) in mechanical thrombectomy is thought to be associated with good clinical outcomes.

OBJECTIVE

To determine FPE rates as a function of thrombectomy technique and to compare clinical outcomes between patients with and without FPE.

METHODS

In July 2020, a literature search on FPE (defined as modified Thrombolysis in Cerebral Infarction (TICI) 2c-3 after a single pass) and modified FPE (mFPE, defined as TICI 2b-3 after a single pass) and mechanical thrombectomy for stroke was performed. Using a random-effects meta-analysis, we evaluated the following outcomes for both FPE and mFPE: overall rates, rates by thrombectomy technique, rates of good neurologic outcome (modified Rankin Scale score ≤2 at day 90), mortality, and symptomatic intracerebral hemorrhage (sICH) rate.

RESULTS

Sixty-seven studies comprising 16 870 patients were included. Overall rates of FPE and mFPE were 28% and 45%, respectively. Thrombectomy techniques shared similar FPE (p=0.17) and mFPE (p=0.20) rates. Higher odds of good neurologic outcome were found when we compared FPE with non-FPE (56% vs 41%, OR=1.78) and mFPE with non-mFPE (57% vs 44%, OR=1.73). FPE had a lower mortality rate (17% vs 25%, OR=0.62) than non-FPE. FPE and mFPE were not associated with lower sICH rate compared with non-FPE and non-mFPE (4% vs 18%, OR=0.41 for FPE; 5% vs 7%, OR=0.98 for mFPE).

CONCLUSIONS

Our findings suggest that approximately one-third of patients achieve FPE and around half of patients achieve mFPE, with equivalent results throughout thrombectomy techniques. FPE and mFPE are associated with better clinical outcomes.

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.

Balloon Guide Catheter is Not Superior to Conventional Guide Catheter when Stent Retriever and Contact Aspiration are Combined for Stroke Treatment

BACKGROUND

The effectiveness of balloon guide catheter (BGC) use has not been prospectively studied and its added value for improving reperfusion in acute ischemic stroke (AIS) treatment has only been reported in studies in which no contact aspiration was combined with the stent retriever (CA + SR).

OBJECTIVE

To compare the reperfusion results and clinical outcomes with and without BGC use when a combined CA + SR strategy is employed in first line to treat AIS.

METHODS

From January 2016 to April 2019, data from the ETIS registry (Endovascular Treatment in Ischemic Stroke) were reviewed. We included patients having undergone endovascular treatment with a combined CA + SR strategy and use or not of a BGC according to the operator's discretion. We compared BGC and nonBGC populations with matching and inverse probability of treatment weighting propensity scores. Primary outcome was the final near-complete/complete revascularization (mTICI2c/3) rate. Secondary outcomes included clinical outcomes and safety considerations.

RESULTS

Among 607 included patients, BGC was used in 32.9% (n = 200), and 190 matched pairs could be found. We found no significant difference in final mTICI2c/3 between patients with and without BGC (60.1% in BGC group compared to 62.7% in nonBGC group (matched RR, 0.92; 95%CI, 0.80 to 1.14)), first-pass mTICI2c/3 (35.1% vs 37.3%, matched RR, 0.94; 95%CI, 0.68 to 1.30), clinical outcome (matched RR of 1.12 (95%CI, 0.85 to 1.47) for favorable outcome.

CONCLUSION

The reperfusion and clinical results with and without BGC use are not significantly different when combined CA + SR are used as a first-line strategy for large vessel occlusion in the setting of AIS.

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.

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.

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.

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.

Successful reperfusion, rather than number of passes, predicts clinical outcome after mechanical thrombectomy

Introduction

For patients undergoing mechanical thrombectomy, numerous (>3) thrombectomy passes may be harmful. However, non-recanalization leads to poor outcomes. For patients requiring multiple thrombectomy passes to achieve reperfusion, it remains unclear if the risk/benefit ratio favors recanalization.

Objective

To test the hypothesis that the benefits afforded by successful reperfusion outweigh the risk conveyed by the numerous passes required.

Methods

We retrospectively reviewed prospectively collected data for patients presenting to a comprehensive stroke center with anterior circulation large vessel occlusion (ACLVO) and undergoing thrombectomy requiring more than one pass over 24 months. We stratified patients into three groups: group 1 (successful reperfusion in 2–3 passes), group 2 (successful reperfusion in ≥4 passes), and group 3 (unsuccessful reperfusion).

Results

250 patients with ACLVO constituted the study cohort. Despite similar demographics, group 2 patients had better clinical outcomes than those in group 3 at 24 hours (National Institutes of Health Stroke Scale (NIHSS) score 13.5 vs 19.1, p<0.001) and at 90 days (modified Rankin Scale score 0–2 rates of 31.1% vs 0.0%, p=0.006) On multivariate logistic regression analysis, age (p=0.034), Alberta Stroke Program Early CT Score (p<0.01), NIHSS score (p=0.02), and parenchymal hematoma type 2 (p=0.015) were significant predictors of functional independence among those who achieved successful reperfusion, but the number of passes required did not predict outcome for these patients (p=0.74).

Conclusion

Patients who achieve successful reperfusion after many passes have better clinical outcomes than those who do not, despite the number of passes and procedural time required. The number of passes required to achieve successful reperfusion beyond the first pass is not a predictor of functional independence.