Aspiration Versus Stent Retriever Thrombectomy for Posterior Circulation Stroke

European Stroke Organisation (ESO) and European Society for Minimally Invasive Neurological Therapy (ESMINT) guideline on acute management of basilar artery occlusion

The aim of the present European Stroke Organisation (ESO) guideline is to provide evidence-based recommendations on the acute management of patients with basilar artery occlusion (BAO). These guidelines were prepared following the Standard Operational Procedure of the ESO and according to the GRADE methodology.Although BAO accounts for only 1-2% of all strokes, it has very poor natural outcome. We identified 10 relevant clinical situations and formulated the corresponding Population Intervention Comparator Outcomes (PICO) questions, based on which a systematic literature search and review was performed. The working group consisted of 10 voting members (five representing ESO and five representing the European Society of Minimally Invasive Neurological Therapy (ESMINT)) and three non-voting junior members. The certainty of evidence was generally very low. In many PICOs, available data were scarce or lacking, hence, we provided expert consensus statements.First, we compared intravenous thrombolysis (IVT) to no IVT, but specific BAO-related data do not exist. Yet, historically, IVT was standard of care for BAO patients who were also included (although in small numbers) in IVT trials. Non-randomized studies of IVT-only cohorts showed a high proportion of favorable outcomes. Expert Consensus suggests using IVT up to 24 hours unless otherwise contraindicated. We further suggest IVT plus endovascular treatment (EVT) over direct EVT. EVT on top of best medical treatment (BMT) was compared with BMT alone within 6 and 6-24 hours from last seen well. In both time windows, we observed a different effect of treatment depending on a) the region where the patients were treated (Europe vs Asia), b) on the proportion of IVT in the BMT arm, and c) on the initial stroke severity. In case of high proportion of IVT in the BMT group and in patients with a National Institutes of Health Stroke Scale (NIHSS) score below 10, EVT plus BMT was not found better than BMT alone. Based on very low certainty of evidence, we suggest EVT+BMT over BMT alone (this is based on results of patients with at least 10 NIHSS points and a low proportion of IVT in BMT). For patients with an NIHSS score below 10, we found no evidence to recommend EVT over BMT. In fact, BMT was non-significantly better and safer than EVT. Furthermore, we found a stronger treatment effect of EVT+BMT over BMT alone in proximal and middle locations of BAO compared with distal location. While recommendations for patients without extensive early ischemic changes in the posterior fossa can, in general, follow those of other PICOs, we formulated an Expert Consensus Statement suggesting against reperfusion therapy in those with extensive bilateral and/or brainstem ischemic changes. Another Expert Consensus suggests reperfusion therapy regardless of collateral scores. Based on limited evidence, we suggest direct aspiration over stent retriever as the first-line strategy of mechanical thrombectomy. As an Expert Consensus, we suggest rescue percutaneous transluminal angioplasty and/or stenting after a failed EVT procedure. Finally, based on very low certainty of evidence, we suggest add-on antithrombotic treatment during EVT or within 24 hours after EVT in patients with no concomitant IVT and in whom EVT was complicated (defined as failed or imminent re-occlusion, or need for additional stenting or angioplasty).

European stroke organisation and European society for minimally invasive neurological therapy guideline on acute management of basilar artery occlusion

The aim of the present European Stroke Organisation (ESO) guideline is to provide evidence-based recommendations on the acute management of patients with basilar artery occlusion (BAO). These guidelines were prepared following the Standard Operational Procedure of the ESO and according to the GRADE methodology. Although BAO accounts for only 1%-2% of all strokes, it has very poor natural outcome. We identified 10 relevant clinical situations and formulated the corresponding Population Intervention Comparator Outcomes (PICO) questions, based on which a systematic literature search and review was performed. The working group consisted of 10 voting members (five representing ESO and five ESMINT) and three non-voting junior members. The certainty of evidence was generally very low. In many PICOs, available data were scarce or lacking, hence, we provided expert consensus statements. First, we compared intravenous thrombolysis (IVT) to no IVT, but specific BAO-related data do not exist. Yet, historically, IVT was standard of care for BAO patients who were also included (albeit in small numbers) in IVT trials. Non-randomised studies of IVT-only cohorts showed high proportion of favourable outcomes. Expert Consensus suggests using IVT up to 24 h unless otherwise contraindicated. We further suggest IVT plus endovascular treatment (EVT) over direct EVT. EVT on top of best medical treatment (BMT) was compared to BMT alone within 6 and 6-24 h from last seen well. In both time windows, we observed a different effect of treatment depending on (a) the region where the patients were treated (Europe vs. Asia), (b) on the proportion of IVT in the BMT arm, and (c) on the initial stroke severity. In case of high proportion of IVT in the BMT group and in patients with NIHSS below 10, EVT plus BMT was not found better than BMT alone. Based on very low certainty of evidence, we suggest EVT + BMT over BMT alone (i.e. based on results of patients with at least 10 NIHSS points and a low proportion of IVT in BMT). For patients with an NIHSS below 10, we found no evidence to recommend EVT over BMT. In fact, BMT was non-significantly better and safer than EVT. Furthermore, we found a stronger treatment effect of EVT + BMT over BMT alone in proximal and middle locations of BAO compared to distal location. While recommendations for patients without extensive early ischaemic changes in the posterior fossa can, in general, follow those of other PICOs, we formulated an Expert Consensus Statement suggesting against reperfusion therapy in those with extensive bilateral and/or brainstem ischaemic changes. Another Expert Consensus suggests reperfusion therapy regardless of collateral scores. Based on limited evidence, we suggest direct aspiration over stent retriever as the first-line strategy of mechanical thrombectomy. As an Expert Consensus, we suggest rescue percutaneous transluminal angioplasty and/or stenting after a failed EVT procedure. Finally, based on very low certainty of evidence, we suggest add-on antithrombotic treatment during EVT or within 24 h after EVT in patients with no concomitant IVT and in whom EVT was complicated (defined as failed or imminent re-occlusion, or need for additional stenting or angioplasty).

Endovascular Treatment for Basilar Artery Occlusion

Basilar artery occlusion (BAO) is a neurological emergency associated with a high risk for adverse outcomes. This review provides evidence on the therapeutic efficacy of intravenous thrombolysis (IVT) and endovascular therapy (EVT) in the treatment of BAO. Historically considered the primary intervention for acute ischemic stroke, IVT has been progressively combined with EVT, which has emerged from recent studies demonstrating clinical benefits, notably in patients presenting with severe stroke. Several randomised controlled trials have shown that EVT improves patient outcomes in select clinical contexts. Future research directions could address therapeutic treatment thresholds, combination strategies, and long-term outcomes.

Contact aspiration for basilar artery occlusion safely reduces the puncture-to-recanalization time

OBJECTIVE

Effective thrombectomies in the posterior circulation remain controversial. Previous reports have demonstrated the superiority of contact aspiration in anterior circulation. Aspiration catheters and stent retrievers are often used alone on a global scale, while combined techniques are commonly used in Japan. This study evaluated the effect of first-line contact aspiration with other strategies for the treatment of basilar artery occlusion.

METHODS

The primary outcome was the frequency of the first-pass effect, and the secondary outcome was the time from puncture to the first-pass effect. A multicenter observational registry including 16 Japanese stroke centers was used. Between December 2013 and February 2021, enrolled patients underwent endovascular thrombectomy for basilar artery occlusion. The efficacy of contact aspiration compared to other methods (including stent retrievers and combined techniques) was evaluated.

RESULTS

Eighty-four patients were included, all of whom had achieved effective recanalization. Twenty-six patients were treated with contact aspiration, 13 with combined technique, and 45 with stent retrievers. The two groups: contact aspiration and non-contact aspiration, had different backgrounds. Both had similar frequencies of effective recanalization and first-pass effects. The contact aspiration group experienced better functional outcomes without statistical significance, while this strategy was significantly associated with a shorter puncture-to-recanalization time (38 vs. 55 minutes, P=0.036). In particular, in the 55 patients with the first-pass effect, multivariate Cox proportional hazard analysis showed that contact aspiration was significantly associated with a shorter time from puncture to first-pass effect, independent of age and etiology of large-artery atherosclerosis (hazard ratio 2.02, 95% confidence intervals 1.10-3.69, P=0.023).

CONCLUSION

This study suggested that contact aspiration for basilar artery occlusion may shorten the puncture-to-first-pass effect, compared to stent retrievers and combined techniques.

Stent retriever versus aspiration based thrombectomy: impact on first pass reperfusion, procedure time, and clinical outcomes in large vessel occlusion. Nationwide registry based cohort study

BACKGROUND

First pass reperfusion (FPR), defined as near complete reperfusion (extended Treatment in Cerebral Ischemia (eTICI) score 2c/3) in a single attempt without rescue therapy has been proposed as a quality metric. However, it remains unclear if the thrombectomy method influences clinical outcome and FPR rate. This study evaluates whether stent retriever and aspiration based thrombectomy differ in FPR rate, technical and clinical outcomes in FPR, and multiple pass reperfusion (MPR).

METHODS

This retrospective, nationwide, multicenter registry study included consecutive patients with proximal anterior or posterior circulation stroke, treated between 2018 and 2021 in Sweden. Outcome measures were FPR rate, procedure time, early neurological improvement (≥4 points on National Institutes of Health Stroke Scale (NIHSS) or a score of 0-1 at 24 hours), favorable functional outcome (modified Rankin Scale score of 0-2 or no decline at 90 days), and mortality at 90 days.

RESULTS

Of 3309 patients (median age 75, median NIHSS 16), 1990 underwent stent retriever and 1319 aspiration based thrombectomy as the firstline method. No difference in FPR rate was observed. Aspiration based thrombectomy showed a shorter procedure time in the FPR group (crude OR (cOR) 6.4 min (95% CI 3.4 to 9.3), adjusted OR (aOR) 8.7 min (95% CI 1.8 to 15.6)) and MPR group (cOR 9.7 min (95% CI 4.0 to 15.4), aOR 17.4 min (95% CI 9.6 to 25.2)), and association with early neurological improvement (cOR 1.21 (95% CI 1.03 to 1.42), aOR 1.40 (95% CI 1.18 to 1.67)) and favorable functional outcome (aOR 1.22 (95% CI 1.01 to 1.47)).

CONCLUSIONS

Our findings suggest that aspiration based thrombectomy was associated with a shorter procedure time and better clinical outcomes than treatment with a stent retriever. No difference was found in FPR rate.

Distal mechanical thrombectomy using beveled tip aspiration zoom catheters: A preliminary study

INTRODUCTION

Distal medium vessel occlusion (DVO) thrombectomy has been shown to be efficacious with safety profiles comparable to large vessel occlusion (LVO) thrombectomy. A novel, highly-trackable, bevel-tipped Zoom 35 catheter can be used as an aspiration catheter for DVO thrombectomy.

METHODS

This is a retrospective, single-arm, multi-institutional observational study evaluating the efficacy and safety of aspiration thrombectomy for DVO using the Zoom 35 catheter. Patient demographics, presenting and discharge NIHSS, primary and rescue thrombectomy, site of occlusion, TICI score, and intracranial hemorrhage were chart abstracted. Descriptive statistics were used to evaluate the efficacy and safety of thrombectomy.

RESULTS

Fourteen patients (mean age 66.64 ± 13.75 years) were included. The mean NIHSS at presentation was 10.79 ± 5.48, and the mean ASPECTS was 9.00 ± 0.89. Nine patients (64.3%) received tPA. Primary occlusion location was M3 in nine cases (64.3%), M2/M3 junction in two cases (14.3%), A2 in one case (7.1%), A3 in one case (7.1%), and P1 in one case (7.1%). TICI scores were 3 in seven cases (50.0%), 2C in three cases (21.4%), and 2B in four cases (28.6%). There was one postoperative SAH (7.1%) and one asymptomatic ICH (7.1%). Mean discharge NIHSS was 3.38 ± 4.44, with a mean decrease of 7.31 from presentation (p < 0.0001, t-test).

CONCLUSION

Zoom 35 beveled-tip aspiration microcatheters are highly trackable and associated with improved radiographic and clinical outcomes for the treatment of DVO with a good safety profile.

Aspiration only versus stent retriever only thrombectomy in basilar artery occlusion: a propensity score-matched analysis of the German Stroke Registry

BACKGROUND

Endovascular treatment has become the standard care for acute basilar artery occlusion (BAO). Uncertainty persists about the optimal thrombectomy technique.

OBJECTIVE

To compare aspiration thrombectomy with stent retriever thrombectomy in patients with BAO in a multicenter real-world patient population.

METHODS

We analyzed data from the German Stroke Registry-Endovascular Treatment (GSR-ET). Patients with isolated BAO who underwent either aspiration or stent retriever thrombectomy were compared, including propensity score matching (PSM). The primary outcome measure was the modified Rankin Scale shift analysis at 90 days. Secondary outcomes included symptomatic intracranial hemorrhage (sICH), procedure complications, and metrics.

RESULTS

Of 13 082 patients in the GSR-ET, 387 patients (mean age 72.0±13.1 years; 45.0% female) fulfilled the inclusion criteria. The thrombectomy technique was aspiration only in 195 (50.4%) and stent retriever only in 192 (49.6%) patients. Functional outcome did not differ between the groups, either before (common OR (cOR) 0.94; 95% CI 0.64 to 1.38) or after PSM (cOR=1.37; 95% CI 0.90 to 2.09). There was no significant difference in sICH (2.6 vs 5.5%; P=0.231; OR=0.46; 95% CI 0.14 to 1.47), but aspiration thrombectomy demonstrated fewer procedure-related complications (4.6% vs 12.5%; P=0.017), a shorter procedure duration (24 vs 48 min; P<0.001), and higher first pass recanalization rates (75.1% vs 44.8%; P<0.001).

CONCLUSIONS

In this study both aspiration and stent retriever thrombectomy showed equal efficacy in terms of functional outcome in patients with BAO. However, procedure complications and metrics might favor aspiration over stent retriever thrombectomy.

Cost-Effectiveness of a Direct-Aspiration First-Pass Technique versus Stent Retriever in Mechanical Thrombectomy

OBJECTIVE

A direct-aspiration first-pass technique (ADAPT) in mechanical thrombectomy has been described in recent studies as an efficacious strategy compared with using a stent retriever (SR). We sought to evaluate for cost differences of ADAPT technique versus SR as an initial approach.

METHODS

We conducted a retrospective analysis of consecutive patients with mechanical thrombectomy at our institution between 2022 and 2023. Patients were grouped into ADAPT with/without SR as a rescue strategy and SR as an initial approach with allowance of concomitant aspiration. Direct cost data (consumables) were obtained. Baseline demographics, stroke metrics, procedure outcomes and cost, and last follow-up outcomes in modified Rankin Scale were compared between 2 groups.

RESULTS

Fifty-six patients were included. Thirty-seven (66.1%) underwent ADAPT, with 11 (29.7%) eventually requiring an SR. Mean age was 64.8 years. The average National Institutes of Health Stroke Scale score was 13.2 in the ADAPT group and 14.0 in the SR group (P = 0.68), with a similar proportion of tissue plasminogen activator (P = 0.53), site of occlusion (P = 0.66), and tandem occlusion (P = 0.69) between the groups. Recanalization was achieved in 94.6% of all patients, with an average of 1.9 passes, 89.3% being TICI 2B or above, with no differences between the 2 groups. Significantly lower cost (P < 0.01) was observed in ADAPT ($14,243.4) compared with SR ($19,003.6). Average follow-up duration was 180.2 days, with mortality of 23.2%. At last follow-up, 55.4% remained functionally independent (modified Rankin Scale score <3) with no difference (P = 0.56) between the ADAPT (59.5%) and SR (47.4%) groups.

CONCLUSIONS

Outcomes were comparable between the ADAPT and SR groups. ADAPT reduced procedural consumables cost by approximately $5000 (25%), even if stent retrievers were allowed to be used for rescue. Establishing ADPAT as initial approach may bring significant direct cost savings while obtaining similar outcomes.

Endovascular therapy versus best medical management for isolated posterior cerebral artery occlusion: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Isolated posterior cerebral artery occlusions (iPCAO) were underrepresented in pivotal randomized clinical trial (RCTs) of endovascular thrombectomy (EVT) in ischemic stroke, and the benefit of EVT in this population is still indeterminate. We performed a systematic review and a meta-analysis to compare the safety and efficacy of EVT compared to best medical management (BMM) in patients with iPCAO.

METHODS

We searched Medline/PubMed, Embase, Web of Science, and the Cochrane databases up to May 2023 for eligible studies reporting outcomes of patients with iPCAO treated with EVT or BMM. We pooled odds ratios (ORs) with corresponding 95% confidence intervals (CI) using a random-effects model.

RESULTS

Seven studies involving 2560 patients were included. EVT was associated with significantly higher likelihood of early neurological improvement (OR, 2.31 [95% CI, 1.38-2.91]; p < 0.00001) and visual field normalization (OR, 3.08 [95% CI, 1.76-5.38]; p < 0.0001) compared to BMM. Rates of good functional outcomes (mRS 0-2) were comparable between the two arms (OR, 0.88 [95% CI, 0.70-1.10]; p = 0.26). Symptomatic intracranial hemorrhage (sICH) was comparable between the two groups (OR, 1.94 [95% CI, 0.96-3.93]; p = 0.07). Mortality was also similar between the two groups (OR, 1.36; [95% CI, 0.77-2.42]; p = 0.29).

CONCLUSIONS

In patients with iPCAO, EVT was associated with visual and early neurological improvement but with a strong trend toward increased sICH. Survival and functional outcomes may be slightly poorer. The role of EVT in iPCAO remains uncertain.

s

BACKGROUND

Patients with acute basilar artery occlusion (ABAO) who undergo combined standard medical treatment (SMT) and endovascular thrombectomy (EVT) may still have unsatisfactory outcomes. This study was conducted to identify the factors that may impact their outcomes.

METHODS

We retrospectively reviewed the data of all patients with ABAO combined with SMT and EVT in the endovascular treatment for acute basilar artery occlusion (ATTENTION) trial. A good outcome is defined as a modified Rankin Scale (mRS) score of 0-3, a poor outcome as mRS score of 4-6, and mortality as death at 90-day follow-up. The study analyzed various factors influencing the patients' good outcomes and mortality.

RESULTS

The study included 221 patients (148 men and 73 women). Among these patients, 45.7% achieved an mRS score of 0-3, while the overall mortality rate was 37.1% (82/221). A good outcome was significantly associated with younger age (adjusted OR 0.96; 95% CI 0.93 to 0.99; P=0.019), a baseline posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS) of 8-10 (adjusted OR 2.34; 95% CI 1.07 to 5.12; P=0.034), and post-procedure pc-ASPECTS of 8-10 (adjusted OR 1.40; 95% CI 1.07 to 1.84; P=0.013). Additionally, time from puncture to reperfusion (adjusted OR 2.02; 95% CI 1.2 to 3.41; P=0.008) and intracranial hemorrhage (adjusted OR 3.59; 95% CI 1.09 to 11.8; P=0.035) were associated with 90-day mortality.

CONCLUSIONS

Younger age, baseline pc-ASPECTS of 8-10, and higher post-procedure pc-ASPECTS could effectively predict good outcomes for patients with ABAO undergoing EVT. Additionally, a prolonged time from puncture to reperfusion and intracranial hemorrhage can independently predict mortality.

TRIAL REGISTRATION NUMBER

NCT04751708.

Network meta-analysis of first-line thrombectomy strategy for acute posterior circulation strokes: a preliminary evaluation for combined approach

Objective

Thrombectomy may provide superior results compared to best medical care for acute posterior circulation strokes (PCS). Contact aspiration (CA), stent retriever (SR), and combined SR + CA (SRA) are commonly employed as first-line techniques. However, the optimal strategy and the role of SRA remain uncertain.

Methods

Systematic searching was conducted in three databases (PubMed, Embase, and Cochrane). Network meta-analyzes were performed using random-effects models. The reperfusion and clinical outcomes were compared. Pooled outcomes were presented as odds ratios (OR) with 95% confidence intervals (CI). Rankograms with surface under the cumulative ranking curve (SUCRA) were calculated.

Results

Seventeen studies were included, involving a total of 645 patients who received first-line CA, 850 patients who received SR, and 166 patients who received SRA. Regarding final recanalization outcomes, both first-line SRA (OR = 3.2, 95%CI 1.4-11.0) and CA (OR = 2.1, 95%CI 1.3-3.7) demonstrated superiority over SR in achieving successful reperfusion [modified Thrombolysis In Cerebral Infarction (mTICI) 2b-3], with values of SUCRA 91.1, 58.5, and 0.4%, respectively. In addition, first-line SRA showed an advantage in achieving final mTICI 2c/3 compared to CA (OR = 3.6, 95%CI 0.99-16.0) and SR (OR = 6.4, 95%CI 1.3-35.0), with SUCRA value of 98.0, 44.7, and 7.2%, respectively. Regarding reperfusion outcome after the first pass, SRA also achieved a higher rate of mTICI 3 than SR (OR = 4.1, 95%CI 1.3-14.0), while CA did not (SUCRA 97.4, 4.6, 48.0%). In terms of safety outcomes, first-line CA was associated with a lower incidence of symptomatic intracranial hemorrhage (sICH) compared to SR (OR = 0.38, 95%CI 0.1-1.0), whereas the SRA technique did not (SUCRA 15.6, 78.6, 55.9%). Regarding clinical prognosis, first-line CA achieved a higher proportion of functional independence (modified Rankin Scale (mRS) 0-2) at 90 days than SR (OR = 1.4, 95%CI 1.1-1.9), whereas SRA did not (SUCRA 90.5, 17.4, 42.1%).

Conclusion

For acute PCS, a first-line CA strategy yielded better results in terms of final successful reperfusion and 90-day functional independence compared to SR. As the combined technique, first-line SRA was associated with superior first-pass and final reperfusion outcomes compared to SR. However, no significant difference was observed in functional independence achieved by first-line SRA compared to the other two strategies. Further high-quality studies are warranted.

How do children fare compared with adults? Comparing relative outcomes after thrombectomy for acute ischemic stroke due to large-vessel occlusion

OBJECTIVE

Safety and efficacy data for endovascular thrombectomy for acute ischemic stroke secondary to large-vessel occlusion in children are lacking compared with those for adults. We undertook an updated systematic review and meta-analysis of endovascular thrombectomy in children and compared their outcomes with adult data.

METHODS

We searched PubMed, Medline, and EMBASE databases to identify prospective and retrospective studies describing patients <18 years treated with endovascular thrombectomy for acute ischemic stroke due to large-vessel occlusion.

RESULTS

Eight pediatric studies were included (n = 192). Most patients were male (53.1 %), experienced anterior circulation large-vessel occlusion (81.8 %), and underwent endovascular thrombectomy by stent retreiver (70.7 %). The primary outcome was change in National Institutes of Health Stroke Scale score from presentation to 24 h after thrombectomy. Secondary outcomes included modified Rankin scale score improvement and 90-day score, recanalization rates, procedural complications, and mortality rates. After treatment, 88.5% of children had successful recanalization; the mean National Institutes of Health Stroke Scale score reduction was 7.37 (95 % CI 5.11-9.63, p < 0.01). The mean reduction of 6.87 (95 %CI 5.00-8.73, p < 0.01) for adults in 5 clinical trials (n = 634) was similar (Qb = 0.11; p = 0.74). Children experienced higher rates of good neurological outcome (76.1 % vs. 46.0 %, p < 0.01) and revascularization (88.5 % vs. 72.3 %, p < 0.01), fewer major periprocedural complications (3.6 % vs. 30.4 %, p < 0.01), and lower mortality (1.0 % vs. 12.9 %, p < 0.01).

CONCLUSIONS

Endovascular thrombectomy may be safe and effective treatment for acute ischemic stroke due to large-vessel occlusion in children. The aggregated data demonstrated high rates of revascularization, favorable long-term neurological outcomes, and low complication rates.

Devices and Techniques

This extensive review explores the intricacies of the three principal mechanical thrombectomy techniques: the stent retriever technique, contact aspiration technique, and a combined approach, and their application in managing acute ischemic stroke. Each technique operates uniquely on the thrombus, leading to differences in their efficacy. Factors including clot size, clot stiffness, vessel tortuosity, and the angle of interaction between the aspiration catheter and the clot significantly influence these differences. Clinical trials and meta-analyses have shown the overall equivalency of these techniques for the treatments of large vessel occlusion and distal medium vessel occlusions. However, there are nuanced differences that emerge under specific clinical circumstances, highlighting the absence of a one-size-fits-all strategy in acute ischemic stroke management. We emphasize the need for future investigations to elucidate these nuances further, aiming to refine procedural strategies and individualize patient care for optimal outcomes.

Comparing Functional Outcomes and Safety Profiles of First-Line Aspiration Thrombectomy Versus Stentriever for Acute Basilar Artery Occlusion: Propensity Analysis of the PC-SEARCH Thrombectomy Registry

BACKGROUND

Aspiration catheters (ASPs) and stentriever thrombectomy devices have comparable safety and efficacy in anterior circulation ischemic strokes. However, there is lack of high-quality comparative data in acute basilar artery occlusions. Our objective is to compare the outcomes and safety of ASPs and stentriever devices in acute basilar artery occlusions.

METHODS

This is an analysis of the retrospectively established PC-SEARCH Thrombectomy (Posterior-Circulation Ischemic Stroke Evaluation: Analyzing Radiographic and Intraprocedural Predictors for Mechanical Thrombectomy) registry. Patients were dichotomized based on their first-line thrombectomy device (ASP and stentriever) and associated with their 90-day functional outcomes, intraprocedural metrics, and safety measures. Propensity analysis based on unequal baseline characteristics was performed. Consecutive patients with acute basilar artery occlusions who received mechanical thrombectomy were included from January 2015 to December 2021. Patients received either first-line contact aspiration or stentriever mechanical thrombectomy. Primary clinical and safety outcomes were 90-day functional independence measured by a modified Rankin Scale score of 0 to 3 and symptomatic intracranial hemorrhage, respectively. Secondary outcomes included puncture-recanalization times, first-pass recanalization rates, crossovers to other thrombectomy device, and neurological/hospital complications.

RESULTS

Five hundred eighteen patients were included in the registry, and a total of 383 patients were included (mean [SD] age, 65.5 [15] years; 228 [59%] men) in this analysis. Of these, 219 patients were first-line ASP while 164 patients received first-line stentriever devices. Median premorbid modified Rankin Scale was zero and median presenting National Institutes of Health Stroke Scale was 17 (interquartile range, 8-26). The proportion of favorable functional outcome was similar between the 2 techniques before (47.3% versus 42.5%; odds ratio, 1.22 [95% CI, 0.78-1.89]; P=0.38) and after propensity matching (odds ratio, 1.46 [95% CI, 0.85-2.49]; P=0.17). In our propensity-matched cohorts, puncture-recanalization times (18 versus 52 minutes; P<0.01) favored first-line ASP; however, first-pass recanalization rates (43.5% versus 44.5%; P=0.90) were similar between groups. First-line ASP was associated with higher rates of crossover (22% versus 6%; P<0.01), whereas stentriever was associated with higher rates of symptomatic intracranial hemorrhage (9.8% versus 3.4%; P=0.04).

CONCLUSIONS

First-line ASP and stentriever methods demonstrated similar functional outcome and recanalization rates. Stentriever methods were associated with higher rates of symptomatic intracranial hemorrhage, whereas ASPs were associated with higher rates of crossover to alternative technique in patients with acute basilar occlusions.

What Is the Evidence for Endovascular Thrombectomy in Posterior Circulation Stroke?

Posterior circulation infarcts comprise approximately 25% of ischemic strokes but are less often treated with recanalization therapy and have longer treatment delays compared with anterior circulation strokes. Among posterior circulation strokes, basilar artery occlusion is associated with the most severe deficits and the worst prognosis. Endovascular thrombectomy is a standard of care for patients with anterior circulation large vessel occlusion, but not until recently were the first randomized controlled trials on endovascular thrombectomy in basilar artery occlusion published. Two of the trials were neutral, whereas two others showed better functional outcome after thrombectomy up to 24 hours of symptom onset compared with best medical treatment, which in most cases had low rates of intravenous thrombolysis. According to observational data, thrombectomy seems to be safe also in isolated posterior cerebral artery occlusions and might be an option for selected patients, even if its outcome benefit is yet to be demonstrated.

Congenital and acquired anomalies of the basilar artery: A pictorial essay

INTRODUCTION

The basilar artery is one of the two cases in our body where an arterial vessel is formed by the union of two others - the vertebral arteries. It provides vascular supply to essential structures for the main vital functions; the posterior cerebral arteries originate from it as terminal branches, and form part of the anastomotic circle of Willis.

IMAGING FINDINGS

Congenital and acquired anomalies of the basilar trunk are described. We provide a schematic and detailed representation of normal anatomical variants - mainly represented by the fenestrated basilar artery or the persistence of carotid-basilar anastomosis; course anomalies are also illustrated, with reference to neuro-vascular conflicts and dolichoectasia. Among congenital anomalies, this pictorial review also shows the variants of the basilar origin, such as in the case of basilar trunk arising from only one of the two vertebral arteries, and the calibre changes - which are represented by aneurysm and hypoplasia. The latter appears to be a risk factor for posterior circulation stroke, when associated with a bilateral posterior foetal variant.Among the acquired forms, this pictorial essay describes some clinical cases of dissections, non-congenital aneurysms, thrombosis and tumour with vascular encasing or compression of basilar artery.

CONCLUSION

CT angiography and MRI allow us to study the posterior intracranial circulation in detail, providing useful pre-treatment information. Therefore, knowledge of congenital or acquired anomalies of the basilar artery is essential for radiologists, neuroradiologists and neurosurgeons.

Treatment of Acute Stroke: Current Practices and Future Horizons

PURPOSE

This review will discuss revascularization of acute ischemic stroke (AIS), discussing the concept of the ischemic penumbra and how thrombolysis and thrombectomy take advantage of it.

SUMMARY

The goal of AIS revascularization is to rescue the ischemic penumbra and the approach to has gone from a time-based to tissue-based approach. Patients must be carefully selected for thrombolysis, which traditionally was limited to those whose last known normal time (LKNT) was known and within 4.5 h. However, newer imaging techniques involving MRI and CT perfusion (CTP) can select patients for thrombolysis whose LKNT is unknown. Alteplase, or tPA, is still the agent of choice for thrombolysis in patients with AIS but tenecteplase (TNK) may be just as effective and more efficient to use. Endovascular thrombectomy (EVT) has shown considerable efficacy for treating large-vessel occlusions and using CTP, patients can be selected for hours after symptom-onset if viable tissue remains. Further research is underway to determine if EVT can be used for medium vessel occlusions and for basilar artery thromboses as well as to determine whether an "EVT-alone" strategy is superior to "tPA + EVT" strategy.

First pass effect in posterior circulation occlusions: Analysis from the CICAT registry

BACKGROUND

The first pass effect (FPE) is an independent predictor of functional independence in patients with large vessel occlusion in anterior circulation ischemic strokes. However, whether it predicts outcome in posterior circulation large vessel occlusion (PC-LVO) is uncertain. We aimed to study the frequency, characteristics, and predictors of FPE and its association with clinical outcomes in PC-LVO.

METHOD

We performed an analysis from the prospective CICAT Registry. All patients with PC-LVO who underwent endovascular therapy between January 2016 and January 2020 were included. A centrally assessed clinical follow-up was performed at 3 months by blinded investigators. FPE was defined as the achievement of modified Thrombolysis In Cerebral Infarction 3 in a single pass of the endovascular thrombectomy device, and multi-pass effect (MPE) if it was achieved in more than one pass. A multivariable analysis was performed to identify whether FPE is an independent predictor of functional independence defined as a modified Rankin Score of 0-2.

RESULTS

We analyzed data from 265 patients in who FPE was achieved in 105 (39.6%). Patients with FPE were more likely to achieve functional independence compared to the non-FPE group (52.4% vs 25.1%, p < .001) and the MPE group (52.4% vs 26.7%, p < .001). FPE was independently associated with functional independence (adjusted odds ratio (aOR): 2.10, 95% confidence interval (CI) 1.01-4.37) but MPE was not (aOR: 0.92, 95% CI 0.40-2.13). Independent predictors of FPE were the use of direct aspiration, embolic mechanism of stroke, and the absence of general anesthesia (GA) use.

CONCLUSIONS

FPE is an independent predictor of functional independence in PC-LVO and was associated with a significantly better outcome than MPE.

Aspiration versus stent retriever for posterior circulation stroke: A meta-analysis

AIMS

New thrombectomy strategies have emerged recently. Differences between posterior circulation stroke management via aspiration and stent retriever remain to be evaluated. We compared the safety and efficacy of aspiration and stent retriever in treating posterior circulation stroke.

METHODS

Three databases (PubMed, Embase, and Cochrane Library) were systematically searched for studies comparing aspiration and stent retriever in patients with posterior circulation stroke. The modified Newcastle-Ottawa scale was used to assess the risk of bias. A random-effects model was used.

RESULTS

Fifteen cohort studies with 1451 patients were included. Pooled results showed a significant difference in total complication (odds ratio [OR] 0.48, 95% confidence interval [CI] [0.30, 0.76], p = 0.002). successful recanalization (1.85, [1.30, 2.64], p = 0.0006), favorable outcome (1.30, [1.02, 1.67], p = 0.04), procedure duration (-22.10, [-43.32, -0.88], p = 0.04), complete recanalization (4.96, [1.06, 23.16], p = 0.009), and first-pass effect (2.59, [1.55, 4.32], p = 0.0003) between the aspiration and stent retriever groups, and in favor of aspiration. There was no significant difference in the outcomes of rescue therapy (1.42, [0.66, 3.05], p = 0.37) between the two groups.

CONCLUSION

Patients with posterior circulation stroke receiving treatment with aspiration achieved better recanalization, first-pass effect, and shorter procedure time. Aspiration may be more secure than a stent retriever.

Treatment of posterior circulation stroke: acute management and secondary prevention

One-fifth of strokes occur in the territory of the posterior circulation, but their management, particularly acute reperfusion therapy and neurointervention procedures for secondary prevention, has received much less attention than similar interventions for the anterior circulation. In this review, we overview the treatment of posterior circulation stroke, including both interventions in the acute setting and secondary prevention. We focus on areas in which the management of posterior circulation stroke differs from that of stroke in general and highlight recent advances.

Effectiveness of acute revascularization of posterior circulation strokes remains in large parts unproven. Thrombolysis seems to have similar benefits and lower hemorrhage risks than in the anterior circulation. The recent ATTENTION and BAOCHE trials have demonstrated that thrombectomy benefits strokes with basilar artery occlusion, but its effect on other posterior occlusion sites remains uncertain. Ischemic and hemorrhagic space-occupying cerebellar strokes can benefit from decompressive craniectomy.

Secondary prevention of posterior circulation strokes includes aggressive treatment of cerebrovascular risk factors with both drugs and lifestyle interventions and short-term dual anti-platelet therapy. Randomized controlled trial (RCT) data suggest basilar artery stenosis is better treated with medical therapy than stenting, which has a high peri-procedural risk. Limited data from RCTs in stenting for vertebral stenosis suggest that intracranial stenosis is currently best treated with medical therapy alone; the situation for extracranial stenosis is less clear where stenting for symptomatic stenosis is an option, particularly for recurrent symptoms; larger RCTs are required in this area.

Endovascular Treatment for Posterior Circulation Stroke: Ways to Maximize Therapeutic Efficacy

The efficacy of endovascular treatment (EVT) in patients with posterior circulation stroke has not been proven. Two recent randomized controlled trials failed to show improved functional outcomes after EVT for posterior circulation stroke (PC-EVT). However, promising results for two additional randomized controlled trials have also been presented at a recent conference. Studies have shown that patients undergoing PC-EVT had a higher rate of futile recanalization than those undergoing EVT for anterior circulation stroke. These findings call for further identification of prognostic factors beyond recanalization. The significance of baseline clinical severity, infarct volume, collaterals, time metrics, core-penumbra mismatch, and methods to accurately measure these parameters are discussed. Furthermore, their interplay on EVT outcomes and the potential to individualize patient selection for PC-EVT are reviewed. We also discuss technical considerations for improving the treatment efficacy of PC-EVT.

Aspiration Versus Stent Retriever Thrombectomy for Distal, Medium Vessel Occlusion Stroke in the Posterior Circulation: A Subanalysis of the TOPMOST Study

BACKGROUND

The optimal endovascular strategy for reperfusing distal medium-vessel occlusions (DMVO) remains unknown. This study evaluates angiographic and clinical outcomes of thrombectomy strategies in DMVO stroke of the posterior circulation.

METHODS

TOPMOST (Treatment for Primary Medium Vessel Occlusion Stroke) is an international, retrospective, multicenter, observational registry of patients treated for DMVO between January 2014 and June 2020. This study analyzed endovascularly treated isolated primary DMVO of the posterior cerebral artery in the P2 and P3 segment. Technical feasibility was evaluated with the first-pass effect defined as a modified Thrombolysis in Cerebral Infarction Scale score of 3. Rates of early neurological improvement and functional modified Rankin Scale scores at 90 days were compared. Safety was assessed by the occurrence of symptomatic intracranial hemorrhage and intervention-related serious adverse events.

RESULTS

A total of 141 patients met the inclusion criteria and were treated endovascularly for primary isolated DMVO in the P2 (84.4%, 119) or P3 segment (15.6%, 22) of the posterior cerebral artery. The median age was 75 (IQR, 62-81), and 45.4% (64) were female. The initial reperfusion strategy was aspiration only in 29% (41) and stent retriever in 71% (100), both achieving similar first-pass effect rates of 53.7% (22) and 44% (44; P=0.297), respectively. There were no significant differences in early neurological improvement (aspiration: 64.7% versus stent retriever: 52.2%; P=0.933) and modified Rankin Scale rates (modified Rankin Scale score 0-1, aspiration: 60.5% versus stent retriever 68.6%; P=0.4). In multivariable logistic regression analysis, the time from groin puncture to recanalization was associated with the first-pass effect (adjusted odds ratio, 0.97 [95% CI, 0.95-0.99]; P<0.001) that in turn was associated with early neurological improvement (aOR, 3.27 [95% CI, 1.16-9.21]; P<0.025). Symptomatic intracranial hemorrhage occurred in 2.8% (4) of all cases.

CONCLUSIONS

Both first-pass aspiration and stent retriever thrombectomy for primary isolated posterior circulation DMVO seem to be safe and technically feasible leading to similar favorable rates of angiographic and clinical outcome.