Outcomes of endovascular treatment of basilar artery occlusion in the stent retriever era: a systematic review and meta-analysis

Mechanical thrombectomy in anterior vs. posterior circulation stroke: A systematic review and meta-analysis

BACKGROUND

High-quality evidence exists for mechanical thrombectomy (MT) treatment of acute ischemic stroke (AIS) due to large vessel occlusion of the anterior circulation (AC-LVO). The evidence for MT treatment of posterior circulation large vessel occlusion (PC-LVO) is weaker, largely drawn from lower quality studies specific to PC-LVO and extrapolated from findings in AC-LVO, and ambiguous with regards to technical success. We performed a systematic review and meta-analysis to compare the technical success and functional outcomes of MT in PC-LVO versus AC-LVO patients.

METHODS

We identified comparative studies reporting on patients treated with MT in AC-LVO versus PC-LVO. The primary outcome of interest was thrombolysis in cerebral infarction (TICI) ≥ 2b. Secondary outcomes included rates of TICI 3, 90-day functional independence, first-pass-effect, average number of passes, and 90-day mortality. A separate random effects model was fit for each outcome measure.

RESULTS

Twenty studies with 12,911 patients, 11,299 (87.5%) in the AC-LVO arm and 1612 (12.5%) in the PC-LVO arm, were included. AC-LVO and PC-LVO patients had comparable rates of successful recanalization [OR = 1.02 [95% CI: 0.79-1.33], p = 0.848). However, the AC-LVO group had greater odds of 90-day functional independence (OR = 1.26 [95% CI: 1.00; 1.59], p = 0.050) and lower odds of 90-day mortality (OR = 0.58 [95% CI: 0.43; 0.79], p = 0.002).

CONCLUSIONS

MT achieves similar rates of recanalization with a similar safety profile in PC-LVO and AC-LVO patients. Patients with PC-LVO are less likely to achieve functional independence after MT. Future studies should identify PC-LVO patients who are likely to achieve favourable functional outcomes.

Imaging predictors of clinical outcomes after endovascular treatment in MRI-selected patients with acute basilar artery occlusion

PURPOSE

We aimed to investigate the impact of baseline infarct area and collateral status (CS), which are imaging predictors of clinical outcome following stroke, after endovascular treatment (EVT) in MRI-selected patients with acute basilar artery occlusion (BAO).

METHODS

Patients with acute BAO who underwent EVT within 24 h after stroke from December 2013 to February 2021 were included in this retrospective, multicenter, observational study. The baseline infarct area was evaluated by the posterior circulation of Acute Stroke Prognosis Early Computed Tomography Score (pc-ASPECTS) using diffuse-weighted imaging (DWI), and CS was assessed by measuring the computed tomography angiography of the basilar artery (BATMAN) score and the posterior circulation collateral score (PC-CS) using magnetic resonance angiography (MRA). A Good outcome was defined as a modified Rankin scale score ≤ 3 at 3 months. For each imaging predictor, a multivariate logistic regression analysis was performed to evaluate its impact on good outcomes.

RESULTS

A total of 86 patients were analyzed, and 37 (43.0%) had a good outcome. The latter showed significantly higher pc-ASPECTS than those without good outcomes. In multivariate analyses, a pc-ASPECTS ≥ 7 was significantly associated with good outcomes (OR, 2.98 [95% CI, 1.10-8.13], P = 0.032), while PC-CS ≥ 4 (OR, 2.49 [95% CI, 0.92-6.74], P = 0.073) and BATMAN score ≥ 5 (OR, 1.51 [95% CI, 0.58-3.98], P = 0.401) were not.

CONCLUSIONS

In MRI-selected patients with acute BAO, pc-ASPECTS on DWI was an independent predictor of clinical outcomes after EVT, while the MRA-based CS assessments were not.

Mechanical Thrombectomy for Stroke Due to Acute Basilar Artery Occlusion, a Safety and Efficacy Analysis

BACKGROUND

Acute basilar artery occlusion accounts for 1% of all ischemic strokes but often leads to devastating neurological injury and mortality. Many institutions still opt for best medical therapy for these patients; however, there is increasing evidence that mechanical thrombectomy (MT) for these patients leads to better outcomes.

OBJECTIVE

To assess the safety and efficacy of MT for patients presenting with acute basilar artery occlusion (BAO).

METHODS

This study was a retrospective chart review of a prospectively maintained database for patients with acute BAO treated with MT from January 2014 through March 2022.

RESULTS

Our study included a total of 74 patients. The mean age was 62.7 years, and 55.4% were male. The most common comorbidity was hypertension (73%). The mean door to puncture time was 75 minutes, and the mean procedure time was 54 minutes. 86.5% of patients had a good modified treatment in cerebral ischemia score (≥2b). There were 4 patients who had procedural complications and 3 who had symptomatic intracerebral hemorrhage. At 90 days, 62.5% of patients had a modified Rankin Scale, 0 to 3. The mortality rate was 32.4% and 2% during hospital admission and 90 days, respectively. On univariate analysis, adjunctive angioplasty/stenting and higher presenting National Institutes of Health Stroke Scale score were associated with modified Rankin Scale 4 to 6 at 90 days ( P -value, .03 and <.001, respectively). Shorter procedure time was associated with modified treatment in cerebral ischemia score ≥ 2b ( P -value, .0015).

CONCLUSION

Our findings showed that MT is safe and effective for patients presenting with acute BAO and is in conjunction with previous literature. The results from upcoming trials should hopefully establish MT as gold standard for these patients.

Endovascular thrombectomy for basilar artery occlusion stroke: Analysis of the German Stroke Registry-Endovascular Treatment

BACKGROUND AND PURPOSE

Acute ischemic stroke due to basilar artery occlusion (BAO) causes the most severe strokes and has a poor prognosis. Data regarding efficacy of endovascular thrombectomy in BAO are sparse. Therefore, in this study, we performed an analysis of the therapy of patients with BAO in routine clinical practice.

METHODS

Patients enrolled between June 2015 and December 2019 in the German Stroke Registry-Endovascular Treatment (GSR-ET) were analyzed. Primary outcomes were successful reperfusion (modified Thrombolysis in Cerebral Infarction [mTICI] score of 2b-3), substantial neurological improvement (≥8-point National Institute of Health Stroke Scale [NIHSS] score reduction from admission to discharge or NIHSS score at discharge ≤1), and good functional outcome at 3 months (modified Rankin Scale [mRS] score of 0-2).

RESULTS

Out of 6635 GSR-ET patients, 640 (9.6%) patients (age 72.2 ± 13.3, 43.3% female) experienced BAO (median [interquartile range] NIHSS score 17 [8, 27]). Successful reperfusion was achieved in 88.4%. Substantial neurological improvement at discharge was reached by 45.5%. At 3-month follow-up, good clinical outcome was observed in 31.1% of patients and the mortality rate was 39.2%. Analysis of mTICI3 versus mTICI2b groups showed considerable better outcome in those with mTICI3 (38.9% vs. 24.4%; p = 0.005). The strongest predictors of good functional outcome were intravenous thrombolysis (IVT) treatment (odds ratio [OR] 3.04, 95% confidence interval [CI] 1.76-5.23) and successful reperfusion (OR 4.92, 95% CI 1.15-21.11), while the effect of time between symptom onset and reperfusion seemed to be small.

CONCLUSIONS

Acute reperfusion strategies in BAO are common in daily practice and can achieve good rates of successful reperfusion, neurological improvement and good functional outcome. Our data suggest that, in addition to IVT treatment, successful and, in particular, complete reperfusion (mTICI3) strongly predicts good outcome, while time from symptom onset seemed to have a lower impact.

Frontline thrombectomy strategy and outcome in acute basilar artery occlusion

BACKGROUND

Novel thrombectomy strategies emanate expeditiously day-by-day counting on access system, clot retriever device, proximity to and integration with the thrombus, and microcatheter disengagement. Nonetheless, the relationship between native thrombectomy strategies and revascularization success remains to be evaluated in basilar artery occlusion (BAO).

PURPOSE

To compare the safety and efficacy profile of key frontline thrombectomy strategies in BAO.

METHODS

Retrospective analyses of prospectively maintained stroke registries at two comprehensive stroke centers were performed between January 2015 and December 2019. Patients with BAO selected after MR imaging were categorized into three groups based on the frontline thrombectomy strategy (contact aspiration (CA), stent retriever (SR), or combined (SR+CA)). Patients who experienced failure of clot retrieval followed by an interchanging strategy were categorized as a fourth (switch) group. Clinicoradiological features and procedural variables were compared. The primary outcome measure was the rate of complete revascularization (modified Thrombolysis in Cerebral Infarction (mTICI) grade 2c-3). Favorable outcome was defined as a 90 day modified Rankin Scale score of 0-2.

RESULTS

Of 1823 patients, we included 128 (33 underwent CA, 35 SR, 35 SR +CA, and 25 switch techniques). Complete revascularization was achieved in 83/140 (59%) primarily analyzed patients. SR +CA was associated with higher odds of complete revascularization (adjusted OR 3.04, 95% CI 1.077 to 8.593, p=0.04) which was an independent predictor of favorable outcome (adjusted OR 2.73. 95% CI 1.152 to 6.458, p=0.02). No significant differences were observed for symptomatic intracranial hemorrhage, functional outcome, or mortality rate.

CONCLUSION

Among BAO patients, the combined technique effectively contributed to complete revascularization that showed a 90 day favorable outcome with an equivalent complication rate after thrombectomy.

Evaluation of the Rapid Arterial oCclusion Evaluation (RACE) scale in Upstate South Carolina, USA

OBJECTIVES

Several stroke assessments have been designed for Emergency Medical Services to identify stroke patients with large vessel occlusion in the prehospital setting. The Rapid Arterial oCclusion Evaluation scale was developed in Spain, yet only few United States-based studies have confirmed findings from Spain. This study was designed to determine if the Rapid Arterial oCclusion Evaluation scale is a valid prehospital stroke assessment for identifying large vessel occlusion patients in South Carolina, USA.

MATERIALS AND METHODS

The performance of the Rapid Arterial oCclusion Evaluation scale was determined by calculating the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy at each score. The discriminative power of the Rapid Arterial oCclusion Evaluation score was evaluated using receiver operator characteristics. Comparison of the Rapid Arterial oCclusion Evaluation Scale to the National Institute of Health Stroke Scale was assessed using the Spearman's coefficient.

RESULTS

The Rapid Arterial oCclusion Evaluation scale had an acceptable discriminative power (c = 0.71). A score of ≥5 had a sensitivity of 0.71, specificity of 0.65, positive predictive value of 0.24, negative predictive value of 0.93, and accuracy of 0.66. There was a significant correlation between the Rapid Arterial Cclusion Evaluation score and the National Institute of Health Stroke Scale (rho = 0.60).

CONCLUSION

The Rapid Arterial oCclusion Evaluation scale performed comparably to the National Institute of Health Stroke Scale in South Carolina; however, performed lower than Spain. Future studies should investigate patient demographics and emergency medical services training to determine if these variables contribute to the results found in this study.

The Charlotte large artery occlusion endovascular therapy outcome score predicts outcome after basilar artery thrombectomy

BACKGROUND AND PURPOSE

The Charlotte Large artery occlusion Endovascular therapy Outcome Score (CLEOS) and Totaled Health Risks in Vascular Events (THRIVE) predict functional outcomes after anterior circulation endovascular thrombectomy (EVT). We evaluated the performance of CLEOS and THRIVE in patients presenting with an acute basilar artery occlusion (BAO) treated with EVT.

METHODS

We conducted a retrospective analysis of a health system's stroke registry. Patients presenting with an acute BAO treated with EVT and evaluated with pre-thrombectomy CT perfusion (CTP) from January 2017 to December 2021 were included. CLEOS = (5 × age) + (10 × National Institutes of Health Stroke Scale [NIHSS]) + Glucose - (150 × CTP cerebral blood volume index) and THRIVE (0-9 points) = age 60-79 years, 1 point; age ≥ 80 years, 2 points; NIHSS 11-20, 2 points; NIHSS ≥ 21, 4 points; hypertension, diabetes mellitus, atrial fibrillation, 1 point each. Multivariable logistic regression was performed for the ability of CLEOS and THRIVE to predict the primary outcome, modified Rankin Scale score 3-6.

RESULTS

Fifty-seven patients had mean age 66.6 (± 14.9) years and median NIHSS 15.5 (5-24). In the multivariable regression analysis, increased CLEOS was associated with significantly higher odds of a poor functional outcome (odds ratio [OR] = 1.0011, 95% confidence interval [CI]: 1.0003-1.0019, p = .008), whereas THRIVE was not (OR = 1.0326, 95% CI: 0.9478-1.1250, p = .466). CLEOS &gt; 503 best predicted poor outcomes.

CONCLUSIONS

A higher CLEOS score was associated with elevated odds of a poor 90-day functional outcome in our cohort of acute BAO patients treated with EVT.

Basilar Artery Thrombectomy Between Evidence-Based Medicine and the Real-World Practice: A Single-Center Experience

BACKGROUND AND AIM

Basilar artery occlusion (BAO) is known for its catastrophic outcomes, whether death or disability, in approximately 70% of patients. Mechanical thrombectomy (MT) has been approved as an intervention in large vessel occlusion of anterior circulation, based on multiple randomized controlled trials (RCTs) and meta-analyses. Even though two RCTs appeared recently, there is still uncertainty about the effect of MT in BAO. Our study aims to report the outcome of MT in BAO and the variables affecting good outcomes and mortality rate.

MATERIALS AND METHODS

We retrospectively collected the clinical and radiological data of 30 BAO patients treated in our center by MT between July 2016 and July 2021. A favorable clinical outcome was considered if mRS was ≤2. A favorable radiological result was considered if modified Thrombolysis in Cerebral Infarction (mTICI) was ≥2b at the end of the intervention. Multiple variables were tested for their effects on favorable clinical outcomes and mortality.

RESULTS

The mean age of the 30 patients was 61.23 ± 16.81 years; 20/30 (66.7%) were male. A favorable functional outcome was achieved in 40.7%. Successful revascularization was achieved in 26 patients (86.7%). Mortality at 90 days was observed in 11 patients (36.7%). The presenting National Institute of Health and Stroke Scale (NIHSS) was the only predictor of mortality, and the optimal cut-off value for death was 15 with area under the curve (AUC) = 0.758 (sensitivity 91% and specificity 59%) and P value = 0.02.

CONCLUSION

Thrombectomy is an effective procedure in BAO which has naturally a bad outcome. The presenting NIHSS might be the only predictor of mortality in our study.

The safety and effectiveness of endovascular treatment for patients with vertebrobasilar artery occlusions: according to the BEST and BASICS criteria

Background:

Whether endovascular treatment (EVT) is safe and effective for vertebrobasilar artery occlusion (VBAO) is yet incompletely understood. Two RCTs, the endovascular treatment versus standard medical treatment for vertebrobasilar artery occlusion (BEST) trail and the Basilar Artery International Cooperation Study (BASICS), concentrating on this field were recently reported.

Objective:

We use real-world registry data of VBAO to compare the outcome of EVT inside and outside the inclusion and exclusion criteria of the BEST and BASICS study to testify the feasibility of the selection paradigms of VBAO in these trials.

Methods:

Consecutive patients with VBAO receiving EVT involving 21 stroke centers were retrospectively included. The safety outcomes [3-month mortality, symptomatic intracranial hemorrhage (sICH), and effectiveness outcomes (the proportion of 3-month functional independence (mRS of 0–2) and favorable outcome (mRS of 0–3)] were compared between VBAO patients who meet or failed to meet the BEST/BASICS selection criteria for EVT.

Results:

Our study cohort consisted of 577 VBAO patients who underwent EVT. Of them, 446 patients had pc-ASPECTS ≧8. Successful reperfusion (mTICI 2b or 3) was achieved in 85.4% (n = 493). There were 418 patients fulfilling the BEST criterion for EVT and 194 fulfilling the BASICS criterion. Regression analysis indicated that adherence to BEST or BASICS criterion for EVT was not independently related to most of the safety and effectiveness outcome except that adherence to BEST was significantly associated with the 3-month favorable outcome (OR_BEST: 1.742, 95% CI: 1.087–2.790). However, when we put pc-ASPECTS into both criteria with a cut-off value of 8, meeting both BEST criterion plus pc-ASPECTS and BASICS criterion plus pc-ASPECTS was independently related to 3-month functional independence (OR_BEST: 1.687, 95% CI: 1.077–2.644; OR_BASIC: 1.653, 95% CI: 1.038–2.631) and favorable outcome (OR_BEST: 2.280, 95% CI: 1.484–3.502; OR_BASIC: 2.153, 95% CI: 1.372–3.378).

Conclusion:

Our study indicated that, based on real-world data of EVT, adherence to BEST or BASICS criterion for EVT was not independently associated with the safety and effectiveness outcome except that adherence to BEST was significantly related to the 3-month favorable outcome. However, the BEST or BASICS selection criterion and pc-ASPECTS ≧8 might be better paradigms for EVT patient selection.

Endovascular Treatment Combined With Standard Medical Treatment Improves Outcomes of Posterior Circulation Stroke: A Systematic Review and Meta-Analysis

Aims

Whether endovascular treatment (EVT) can further improve the prognosis of patients with posterior circulation ischemic stroke (PCIS) is unclear. This meta-analysis aims to compare the efficacy and safety of PCIS patients treated with EVT plus standard medical treatment (SMT) and SMT alone.

Methods

We systematically searched for relevant randomized controlled trials (RCTs) and prospective cohort trials in MEDLINE, EMBASE, and the Cochrane Library up to February 2022. The primary outcome was favorable functional outcome of the modified Rankin Scale (mRS) with scores of 0-2 or 0-3; secondary outcomes included successful recanalization rate, intracranial hemorrhage (ICH), or symptomatic intracranial hemorrhage (sICH) after treatment and 90-day mortality.

Results

We identified six studies including 1, 385 PCIS patients (957 with EVT plus SMT; 428 with SMT alone). EVT plus SMT substantially improved 90-day functional outcomes compared with SMT alone [mRS score of 0-2: RR=1.95, 95% CI (1.52 - 2.51), P < 0.001; mRS score of 0-3: RR = 1.85, 95% CI (1.49 - 2.30), P < 0.001, respectively]. Moreover, compared with SMT, combined treatment significantly improved the rate of successful recanalization [RR = 5.03, 95% CI (3.96-6.40), P < 0.001] and reduced 90-day mortality [RR = 0.71, 95% CI (0.63-0.79), P < 0.001] despite a higher risk of ICH [RR = 6.13, 95% CI (2.50-15.02), P < 0.001] and sICH [RR = 10.47, 95% CI [2.79-39.32), P = 0.001].

Conclusion

Low-to-moderate evidence from RCTs and non-RCTs showed that increased ICH and sICH risk of EVT plus SMT did not translate to a higher risk of unfavorable outcomes compared with SMT and could even promote independence at 90 days in a real-world cohort.

Effect of Imaging Markers on Reperfusion Therapy in Basilar Artery Occlusion

Objective

We aimed to investigate the effectiveness of endovascular therapy (EVT) versus intravenous thrombolysis (IVT) in patients with basilar artery occlusion (BAO), based on the information of advanced imaging.

Methods

We analyzed data of stroke patients with radiologically confirmed BAO within 24 hours. BAO subjects were categorized into “top‐of‐the‐basilar” syndrome (TOBS) and other types. An initial infarct size of <70ml and a ratio of ischemic tissue to infarct volume of ≥1.8 was defined as “target mismatch.” The primary outcome was a good outcome, defined as a modified Rankin Scale score of 0 to 3 at 3 months. Propensity score adjustment and inverse probability of treatment weighting (IPTW) propensity score methods were used.

Results

Among 474 BAO patients, 93 (19.6%) were treated with IVT prior to EVT, 91 (19.2%) were treated with IVT alone, 95 (20.0%) were treated with EVT alone, and 195 (41.1%) were treated with antithrombotic therapy. In IPTW analyses, we found no benefit of EVT over IVT for good outcome in either TOBS patients (odds ratio = 1.08, 95% confidence interval [CI] = 0.88–1.31) or those with other types (odds ratio = 1.13, 95% CI = 0.94–1.36). However, in patients with other types, if there existed a target mismatch, EVT was independently related to good outcome (odds ratio = 1.46, 95% CI = 1.17–1.81).

Interpretation

The “target mismatch profile” seems to be a possible candidate selection standard of EVT for those with other types of BAO. Future studies should separate TOBS from other types of BAO, and try to use advanced imaging. ANN NEUROL 2022;92:97–106

Perfusion Imaging Predicts Favorable Outcomes after Basilar Artery Thrombectomy

OBJECTIVE

Perfusion imaging identifies anterior circulation stroke patients who respond favorably to endovascular thrombectomy (ET), but its role in basilar artery occlusion (BAO) is unknown. We hypothesized that BAO patients with limited regions of severe hypoperfusion (time to reach maximum concentration in seconds [Tmax] > 10) would have a favorable response to ET compared to patients with more extensive regions involved.

METHODS

We performed a multicenter retrospective cohort study of BAO patients with perfusion imaging prior to ET. We prespecified a Critical Area Perfusion Score (CAPS; 0-6 points), which quantified severe hypoperfusion (Tmax > 10) in cerebellum (1 point/hemisphere), pons (2 points), and midbrain and/or thalamus (2 points). Patients were dichotomized into favorable (CAPS ≤ 3) and unfavorable (CAPS > 3) groups. The primary outcome was a favorable functional outcome 90 days after ET (modified Rankin Scale = 0-3).

RESULTS

One hundred three patients were included. CAPS ≤ 3 patients (87%) had a lower median National Institutes of Health Stroke Scale score (NIHSS; 12.5, interquartile range [IQR] = 7-22) compared to CAPS > 3 patients (13%; 23, IQR = 19-36; p = 0.01). Reperfusion was achieved in 84% of all patients, with no difference between CAPS groups (p = 0.42). Sixty-four percent of reperfused CAPS ≤ 3 patients had a favorable outcome compared to 8% of nonreperfused CAPS ≤ 3 patients (odds ratio [OR] = 21.0, 95% confidence interval [CI] = 2.6-170; p < 0.001). No CAPS > 3 patients had a favorable outcome, regardless of reperfusion. In a multivariate regression analysis, CAPS ≤ 3 was a robust independent predictor of favorable outcome after adjustment for reperfusion, age, and pre-ET NIHSS (OR = 39.25, 95% CI = 1.34->999, p = 0.04).

INTERPRETATION

BAO patients with limited regions of severe hypoperfusion had a favorable response to reperfusion following ET. However, patients with more extensive regions of hypoperfusion in critical brain regions did not benefit from endovascular reperfusion. ANN NEUROL 2021.

Endovascular therapy in basilar artery occlusion in Sweden 2016-2019-a nationwide, prospective registry study

Purpose

We present the first nationwide study on endovascular therapy for basilar artery occlusion (BAO) from early hospital management to 3-month outcome.

Methods

Data were collected on all acute ischaemic stroke patients registered 2016–2019 in the two national quality registers for stroke care and endovascular therapy (EVT), receiving EVT for BAO and subclassified into proximal, middle and distal.

Results

In all, 251 patients were included: 69 proximal, 73 middle and 109 distal BAO. Patients with proximal BAO were younger (66, middle 71, distal 76, p < 0.0001), less often female (27.5%, middle 47.9%, distal 47.7%, p = 0.015), more often smokers (28.6%, middle 20.3%, distal 11.5%, p < 0.0001), and fewer had atrial fibrillation (13.2%, middle 24.7%, distal 48.6%, p < 0.0001). Level of consciousness and NIHSS score did not differ by BAO subtype and 52.2% were alert on admission. Time from groin puncture to revascularization was significantly longer in patients with proximal BAO (71, middle 46, distal 42 min, p < 0.0001), and angioplasty and/or stenting was more often performed in patients with proximal (43.4%) and middle (27.4%) than distal (6.4%) BAO (p < 0.0001). Cumulative 90-day mortality was 38.6% (proximal 50.7%, middle 32.9%, distal 34.9%, p = 0.02). Older and pre-stroke dependent patients had higher mortality, as did patients in whom angioplasty/stenting was performed.

Conclusion

We confirm a serious outcome in BAO despite endovascular therapies, and demonstrate important differences relating to occlusion location in baseline characteristics, procedural time, therapeutic measures and outcome. Further in-depth analyses of factors affecting outcome in BAO are warranted.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00234-021-02843-3.

Value of machine learning to predict functional outcome of endovascular treatment for acute ischaemic stroke of the posterior circulation

PURPOSE

Clinical outcomes vary considerably among individuals with vessel occlusion of the posterior circulation. In the present study we evaluated machine learning algorithms in their ability to discriminate between favourable and unfavourable outcomes in patients with endovascular treatment of acute ischaemic stroke of the posterior circulation.

METHODS

This retrospective study evaluated three algorithms (generalised linear model, K-nearest neighbour and random forest) to predict functional outcomes at dismissal of 30 patients with acute occlusion of the basilar artery who were treated with thrombectomy. Input variables encompassed baseline as well as peri and postprocedural data. Favourable outcome was defined as a modified Rankin scale score of 0-2 and unfavourable outcome was defined as a modified Rankin scale score of 3-6. The performance of the algorithms was assessed with the area under the receiver operating curve and with confusion matrixes.

RESULTS

Successful reperfusion was achieved in 83%, with 30% of the patients having a favourable outcome. The area under the curve was 0.93 for the random forest model, 0.86 for the K-nearest neighbour model and 0.78 for the generalised linear model. The accuracy was 0.69 for the generalised linear model and 0.84 for the random forest and the K nearest neighbour models.

CONCLUSION

Favourable and unfavourable outcomes at dismissal of patients with acute ischaemic stroke of the posterior circulation can be predicted immediately after the follow-up non-enhanced computed tomography using machine learning.

Cerebral blood volume index as a predictor of functional independence after basilar artery thrombectomy

BACKGROUND AND PURPOSE

The role of CT perfusion (CTP)in the evaluation of acute basilar artery occlusion (aBAO) patients undergoing endovascular thrombectomy (EVT) is unclear. We investigated the association of individual CTP parameters with functional outcomes in aBAO patients undergoing EVT.

METHODS

A health system's prospectively collected code stroke registry was used in this retrospective analysis of aBAO patients treated with EVT presenting between January 2017 and February 2021 with pre-EVT CTP. The primary outcome measure was modified Rankin Scale (mRS) score 0-2 at 90 days. Factors with a univariate association (p < .05) with mRS 0-2 were combined in a multivariable regression model to determine independent predictors of 90-day favorable functional outcome.

RESULTS

Forty-six subjects, with median age 67 years and median National Institutes of Health Stroke Scale 16, were included, of whom 17 (37%) achieved mRS 0-2 at 90 days. In the multivariable logistic regression model, CTP cerebral blood volume (CBV) index (per 0.1-point increase, odds ratio = 1.843; 95% confidence interval: 1.039, 3.268; p-value .0365) was independently associated with a favorable 90-day outcome.

CONCLUSIONS

CBV index was independently associated with a favorable 90-day outcome in aBAO patients treated with EVT, a novel finding in this patient population. CBV index may assist in treatment and prognosis discussions and inform future studies investigating the role of CTP in aBAO.

Basilar Artery Occlusion Chinese Endovascular Trial: Protocol for a prospective randomized controlled study

RATIONALE

There are no randomized trials examining the best treatment for acute basilar artery occlusion in the 6-24-hour time window.

AIMS

To assess the safety and efficacy of thrombectomy for stroke due to basilar artery occlusion in patients randomized within 6-24 h from symptom onset or time last seen well.

SAMPLE SIZE

For an estimated difference of 20% in proportions of the primary outcome between the two groups, 318 patients will be included for 5% significance and 90% power with a planned interim analysis after two-thirds of the sample size (212 patients) have achieved the 90 days follow-up.

METHODS AND DESIGN

A prospective, multi-center, randomized, controlled, open-label and blinded-endpoint trial. The randomization employs a 1:1 ratio of mechanical thrombectomy with the detachable Solitaire thrombectomy device and best medical therapy (BMT) vs. BMT alone.

STUDY OUTCOMES

The primary outcome will be the proportion of patients achieving modified Rankin Scale (mRS) 0-3 at 90 days. Key secondary outcomes are: dramatic early favorable response, dichotomized mRS score (0-2 vs. 3-6 and 0-4 vs. 5-6) at 90 days, ordinal (shift) mRS analysis at 90 days, infarct volume at 24 h, vessel recanalization at 24 h in both treatment arms, and successful recanalization in the thrombectomy arm according to the modified thrombolysis in cerebral infarction (mTICI) classification defined as mTICI 2 b or 3. Safety variables are mortality at 90 days, symptomatic intracranial hemorrhage rates at 24 h, and procedure-related complications.

DISCUSSION

Results from this trial will indicate whether mechanical thrombectomy is superior to medical management alone in achieving favorable outcomes in subjects with acute stroke caused by basilar artery occlusion presenting within 6-24 h from symptom onset.Trial registration: URL: http://www.clinicaltrials.gov. ClinicalTrials.gov Identifier: NCT02737189.

Thrombectomy for secondary distal, medium vessel occlusions of the posterior circulation: seeking complete reperfusion

BACKGROUND

Whether to approach distal occlusions endovascularly or not in medium-sized vessels secondary to proximal large vessel occlusion stroke remains unanswered.

OBJECTIVE

To investigates the technical feasibility and safety of thrombectomy for secondary posterior circulation distal, medium vessel occlusions (DMVO).

METHODS

TOPMOST (Treatment fOr Primary Medium vessel Occlusion STroke) is an international, retrospective, multicenter, observational registry of patients treated for distal cerebral artery occlusions. This study subanalysis endovascularly treated occlusions of the posterior cerebral artery in the P2 and P3 segment secondary preprocedural or periprocedural thrombus migration between January 2014 and June 2020. Technical feasibility was evaluated with the modified Thrombolysis in Cerebral Infarction (mTICI) scale. Procedural safety was assessed by the occurrence of symptomatic intracranial hemorrhage (sICH) and intervention-related serious adverse events.

RESULTS

Among 71 patients with secondary posterior circulation DMVO who met the inclusion criteria, occlusions were present in 80.3% (57/71) located in the P2 segment and in 19.7% (14/71) in the P3 segment. Periprocedural migration occurred in 54.9% (39/71) and preprocedural migration in 45.1% (32/71) of cases. The first reperfusion attempt led in 38% (27/71) of all cases to mTICI 3. On multivariable logistic regression analysis, increased numbers of reperfusion attempts (adjusted odds ratio (aOR)=0.39, 95% CI 0.29 to 0.88, p=0.009) and preprocedural migration (aOR=4.70, 95% CI,1.35 to 16.35, p=0.015) were significantly associated with mTICI 3. sICH occurred in 2.8% (2/71).

CONCLUSION

Thrombectomy for secondary posterior circulation DMVO seems to be safe and technically feasible. Even though thrombi that have migrated preprocedurally may be easier to retract, successful reperfusion can be achieved in the majority of patients with secondary DMVO of the P2 and P3 segment.

[Border areas of thrombectomy]

Die mechanische Thrombektomie (MT) hat sich als Standardverfahren für die Behandlung akuter ischämischer Schlaganfälle aufgrund eines Verschlusses einer großen, proximalen Hirnarterie der vorderen Zirkulation etabliert. Dennoch sind nach aktuellen Guidelines noch große Patientenkollektive von dieser hocheffektiven Behandlungsmethode ausgeschlossen. Diese Arbeit gibt daher einen Überblick über mögliche Erweiterungen der Behandlungsindikationen für die MT, wie z. B. Patienten im erweiterten Zeitfenster, mit distalen Verschlüssen, mit großem Infarktkern oder auch für sehr alte (> 90 Jahre) und junge (0–17 Jahre) Patienten. Zusätzlich besprechen wir neue Entwicklungen in der interventionellen Behandlung von Schlaganfällen, wie z. B. neue Triage-Konzepte oder die Fragestellung, ob die zusätzliche intravenöse Thrombolyse bei MT-Patienten notwendig ist. Abschließend geben wir für die besprochenen Behandlungsindikationen unsere Einschätzungen basierend auf der aktuellen Literatur und unserer klinischen Erfahrung.

First-line contact aspiration versus first-line stent retriever for acute posterior circulation strokes: an updated meta-analysis

BACKGROUND

Both stent retriever (SR) and contact aspiration (CA) are widely used as first-line strategies for acute posterior circulation strokes (PCS). However, it is still unclear how CA and SR compare as the first-line treatment of acute PCS. Several new studies have been published recently, so we aimed to perform an updated meta-analysis.

METHODS

The meta-analysis was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) statement. Random-effects models were performed to pool the outcomes and the value of I² was calculated to assess the heterogeneity.

RESULTS

Ten observational studies with 1189 patients were included, among whom 492 received first-line CA and 697 received first-line SR. The pooled results revealed that first-line CA could achieve a significantly higher proportion of modified Thrombolysis In Cerebral Infarction (mTICI) 2b/3 (OR 1.90, 95% CI 1.33 to 2.71, I²=0%), mTICI 3 (OR 1.95, 95% CI 1.15 to 3.31, I²=59.6%), first-pass effect (OR 2.91, 95% CI 1.51 to 5.58, I²=0%), lower incidence of new-territory embolic events (OR 0.20, 95% CI 0.05 to 0.83, I²=0%), and shorter procedure time (mean difference -29.4 min, 95% CI -46.8 to -12.0 min, I²=62.8%) compared with first-line SR. At 90-day follow-up, patients subjected to first-line CA showed a higher functional independence (modified Rankin Scale score 0-2; OR 1.38, 95% CI 1.01 to 1.87, I²=23.5%) and a lower mortality (OR 0.71, 95% CI 0.50 to 1.00, p=0.050, I²=0%) than those subjected to first-line SR.

CONCLUSIONS

This meta-analysis suggests that the first-line CA strategy could achieve better recanalization and clinical outcomes for acute PCS than first-line SR. Limited by the quality of included studies, this conclusion should be drawn with caution.

A Single-Center Experience of Endovascular Treatment in Subtypes of Basilar Artery Occlusion: Embolization Caused by Tandem Vertebral Artery Stenosis May Be Associated with Better Outcomes

OBJECTIVE

Basilar artery occlusion (BAO) is a severe condition with high mortality. However, surgical procedures and outcomes of BAO with different pathologic subtypes have not been fully clarified. This study compared the surgical procedures and clinical outcomes of mechanical thrombectomy in different subtypes of BAO.

METHODS

Eighty-six patients with acute BAO receiving endovascular treatment between October 2015 and July 2019 were retrospectively analyzed and placed in 3 groups: pure embolism (group 1), arterial-arterial embolism from steno-occlusion of the tandem vertebral artery (group 2), and in situ atherosclerotic thrombosis (group 3). Recanalization rates, procedure times, surgical characteristics, and clinical outcomes were analyzed.

RESULTS

Groups 1, 2, and 3 included 33 (38.4%), 17 (19.8%), and 36 (41.9%) patients, respectively. The overall successful recanalization rate was 95.3%, and the good outcome rate was 61.6%. The procedure time in group 1 was shorter than the time in groups 2 and 3 (P < 0.001). The clinical good outcome rate was higher in group 2 than in group 1 (88.2% vs. 54.5%; P = 0.017). Groups 1 and 3 had similar good outcome rates (54.5% vs. 55.6%; P = 0.933). Twenty-seven patients received stent angioplasty: 10 of 17 in group 2 (58.8%) and 17 of 36 in group 3 (47.2%).

CONCLUSIONS

The outcome of endovascular treatment for BAO varies among patients with different pathologic mechanisms. Patients with embolism from tandem vertebral artery steno-occlusion achieved the best outcomes. Rescue treatment was more common in patients with embolic BAO with tandem vertebral artery steno-occlusion and BAO with in situ atherosclerotic thrombosis.

Computed Tomography Perfusion Deficit Volumes Predict Functional Outcome in Patients With Basilar Artery Occlusion

[Figure: see text].

[Endovascular treatment of acute basilar artery occlusions]

BACKGROUND

Since the publication of the large randomized controlled thrombectomy trials, endovascular treatment (EVT) has become the standard of care for acute stroke patients with anterior circulation large vessel occlusion (acLVO); however, the treatment of patients with an intracranial occlusion in the posterior circulation and in particular of the basilar artery has not been proven. Thus, there is uncertainty regarding the indications for EVT due to the poor evidence situation.

OBJECTIVE

This review article addresses the current data on EVT in the posterior circulation and the most recent study results. Furthermore, the pathophysiological aspects, indications and specific features in the treatment of these patients are also discussed.

RESULTS

Despite limited evidence for EVT, this treatment modality has gained significant clinical relevance for the treatment of stroke patients with vascular occlusions in the posterior circulation. From a technical point of view, vascular occlusions in the posterior circulation and particularly of the basilar artery are easily accessible, although the etiology of occlusions and necessary techniques differ compared to occlusions in the anterior circulation.

CONCLUSION

Compared to acLVO, EVT in the posterior circulation differs with respect to the current evidence, indications and technique. As current data have not proven its effectiveness for improved clinical outcome, treatment decisions must still be made individually based on institutional protocols, particularly for patients in the late time window or for patients already with signs of extensive infarction on baseline imaging.

Expanding indications for endovascular thrombectomy-how to leave no patient behind

Endovascular thrombectomy (EVT) has become standard of care for large vessel occlusion strokes but current guidelines exclude a large proportion of patients from this highly effective treatment. This review therefore focuses on expanding indications for EVT in several borderline indications such as patients in the extended time window, patients with extensive signs of infarction on admission imaging, elderly patients and patients with pre-existing deficits. It also discusses the current knowledge on intravenous thrombolysis as an adjunct to EVT and EVT as primary therapy for distal vessel occlusions, for tandem occlusions, for basilar artery occlusions and in pediatric patients. We provide clear recommendations based on current guidelines and further literature.

Posterior Circulation Endovascular Thrombectomy for Large-Vessel Occlusion: Predictors of Favorable Clinical Outcome and Analysis of First-Pass Effect

BACKGROUND AND PURPOSE

Successful vessel recanalization in posterior circulation large-vessel occlusion is considered crucial, though the evidence of clinical usefulness, compared with the anterior circulation, is not still determined. The aim of this study was to evaluate predictors of favorable clinical outcome and to analyze the effect of first-pass thrombectomy.

MATERIALS AND METHODS

A retrospective, multicenter, observational study was conducted in 10 high-volume stroke centers in Europe, including the period from January 2016 to July 2019. Only patients with an acute basilar artery occlusion or a single, dominant vertebral artery occlusion ("functional" basilar artery occlusion) who had a 3-month mRS were included. Clinical, procedural, and radiologic data were evaluated, and the association between these parameters and both the functional outcome and the first-pass effect was assessed.

RESULTS

A total of 191 patients were included. A lower baseline NIHSS score (adjusted OR, 0.77; 95% CI, 0.61-0.96; P = .025) and higher baseline MR imaging posterior circulation ASPECTS (adjusted OR, 3.01; 95% CI, 1.03-8.76; P = .043) were predictors of better outcomes. The use of large-bore catheters (adjusted OR, 2.25; 95% CI, 1.08-4.67; P = .030) was a positive predictor of successful reperfusion at first-pass, while the use of a combined technique was a negative predictor (adjusted OR, 0.26; 95% CI, 0.09-0.76; P = .014).

CONCLUSIONS

The analysis of our retrospective series demonstrates that a lower baseline NIHSS score and a higher MR imaging posterior circulation ASPECTS were predictors of good clinical outcome. The use of large-bore catheters was a positive predictor of first-pass modified TICI 2b/3; the use of a combined technique was a negative predictor.

Values of Baseline Posterior Circulation Acute Stroke Prognosis Early Computed Tomography Score for Treatment Decision of Acute Basilar Artery Occlusion

BACKGROUND AND PURPOSE

This study aimed to analyze the impact of baseline posterior circulation Acute Stroke Prognosis Early Computed Tomography Score (pc-ASPECTS) on the efficacy and safety of endovascular therapy (EVT) for patients with acute basilar artery occlusion.

METHODS

The BASILAR was a nationwide prospective registry of consecutive patients with a symptomatic and radiologically confirmed acute basilar artery occlusion within 24 hours of symptom onset. We estimated the effect of standard medical therapy alone (SMT group) versus SMT plus EVT (EVT group) for patients with documented pc-ASPECTS on noncontrast CT, both as a categorical (0-4 versus 5-7 versus 8-10) and as a continuous variable. The primary outcomes included favorable functional outcomes (modified Rankin Scale ≤3) at 90 days and mortality within 90 days.

RESULTS

In total, 823 cases were included: 468 with pc-ASPECTS 8 to 10 (SMT: 71; EVT: 397), 317 with pc-ASPECTS 5 to 7 (SMT: 85; EVT: 232), and 38 with pc-ASPECTS 0 to 4 (SMT: 13; EVT: 25). EVT was associated with higher rate of favorable outcomes (adjusted relative risk with 95% CI, 4.35 [1.30-14.48] and 3.20 [1.68-6.09]; respectively) and lower mortality (60.8% versus 77.6%, P=0.005 and 35.0% versus 66.2%, P<0.001; respectively) than SMT in the pc-ASPECTS 5 to 7 and 8 to 10 subgroups. Continuous benefit curves also showed the superior efficacy and safety of EVT over SMT in patients with pc-ASPECTS ≥5. Furthermore, the prognostic effect of onset to puncture time on favorable outcome with EVT was not significant after adjustment for pc-ASPECTS (adjusted odds ratio, 0.98 [95% CI, 0.94-1.02]).

CONCLUSIONS

Patients of basilar artery occlusion with pc-ASPECTS ≥5 could benefit from EVT. The baseline pc-ASPECTS appears more important for decision making and predicting prognosis than time to EVT. Registration: URL: http://www.chictr.org.cn. Unique identifier: ChiCTR1800014759.

Age and discharge modified Rankin score are associated with 90-Day functional outcome after basilar artery occlusion treated with endovascular therapy

INTRODUCTION

Prognostic factors for functional outcome after basilar artery occlusion (BAO) treated with modern endovascular therapy (EVT) are sparse. We investigated the association between clinical characteristics, readily available imaging variables, and outcome in BAO patients treated with EVT.

METHODS

Retrospective analysis from a large healthcare system's prospectively collected code stroke registry of acute BAO patients treated with EVT between January 2017-January 2020. The primary outcome measure was a favorable 90-day modified Rankin score (mRS) of 0-2.

RESULTS

65 patients (median age 67 years, 57% male, median NIHSS 16) met the study inclusion criteria. Thrombolysis in Cerebral Infarction (TICI) 2 b-3 revascularization was achieved in 57/65 patients (88%) with a median time to revascularization of 445 minutes [IQR 302-840]. Ninety-day good outcome was seen in 35% (23/65) of patients. In a univariate analysis, age, history of ischemic stroke, baseline NIHSS, BAO site, and discharge mRS were associated with significant differences between the good and poor outcome groups. A multivariable logistic regression analysis demonstrated an independent association with 90-day good outcome and younger age (per 1-year, OR 0.79, 95% CI 0.64, 0.98) and good discharge mRS (0-2) (OR > 999.99, 95% CI 13.26, > 999.99).

CONCLUSIONS

Patients presenting with an acute BAO treated with modern EVT have a good 90-day outcome in over one-third of cases. Age and discharge mRS are independently associated with good 90-day outcome. Additional studies may focus on factors that can enhance discharge function after BAO, a novel prognostic indicator for favorable 90-day outcome in our study.

Effect of manual aspiration thrombectomy using large-bore aspiration catheter for acute basilar artery occlusion: comparison with a stent retriever system

Background

A large-bore aspiration catheter can be employed for recanalization of acute basilar artery occlusion. Here we compare the results of mechanical thrombectomy using a stent retriever (SR) and manual aspiration thrombectomy (MAT) using a large-bore aspiration catheter system as a first-line recanalization method in acute basilar artery occlusion (BAO).

Methods

The records of 50 patients with acute BAO who underwent mechanical thrombectomy were retrospectively reviewed. Patients were assigned to one of two groups based on the first-line recanalization method. The treatment and clinical outcomes were compared.

Results

Sixteen (32%) patients were treated with MAT with a large-bore aspiration catheter and 34 (68%) with a SR as the first-line treatment method. The MAT group had a shorter procedure time (28 vs. 65 min; p = 0.001), higher rate of first-pass recanalization (68.8% vs. 38.2%, p = 0.044), and lower median number of passes (1 vs 2; p = 0.008) when compared with the SR group. There was no significant difference in the incidence of any hemorrhagic complication (6.3% vs. 8.8%; p = 0.754) between the groups. However, there were four cases of procedure-related subarachnoid hemorrhage (SAH) in the SR group and one death occurred due to massive hemorrhage.

Conclusions

Selection of MAT using a large-bore aspiration catheter for acute BAO may be a safe and effective first-line treatment method with higher first-pass recanalization rate and shorter procedure time than SR.

Trials in thrombectomy for acute ischemic stroke: Describing the state of clinical research in the field

BACKGROUND

Endovascular thrombectomy has revolutionized treatment of ischemic stroke. Given the clinical and socioeconomic support for thrombectomy, new devices, procedures, and pharmaceuticals have emerged in recent years, and have been subject to a growing number of clinical trials worldwide.

OBJECTIVE

To define the current state of thrombectomy clinical trials, highlight recent trends, and help guide future research in this area.

METHODS

Current and previous clinical trials involving thrombectomy for ischemic stroke were queried from the Clinicaltrials.gov database. Trials were categorized by their current status, study design, funding type, exclusion criteria, study phase, enrollment, start and completion dates, country of origin, item of investigation, outcome metrics, and whether a peer-reviewed publication was linked to the trial.

RESULTS

Querying the ClinicalTrials.gov registry yielded 196 trials, of which 161 (82.1 %) were started within the past 5 years. The average time to completion was 30.6 months. A total of 62 studies (31.6 %) examined the safety or efficacy of a thrombectomy device, 29 (14.8 %) investigated a pharmacological intervention alone or in combination with a device, 59 (30.1 %) examined aspects of the endovascular procedure on patient outcomes, and 14 (7.2 %) examined diagnostic utility during thrombectomy. Most trials were funded by academic centers (53.1 %) or industry (34.7 %). Although the United States contributed the most studies overall (59; 30.1 %), studies from European and Asian countries have been increasing since 2015.

CONCLUSION

These trends indicate an increasing number of trials starting the past few years, with most occurring in Europe and examining devices or aspects of the thrombectomy procedure.

A New Angiographic Collateral Grading System for Acute Basilar Artery Occlusion Treated with Endovascular Therapy

Poor clinical outcomes despite endovascular therapy (EVT) are common in patients with acute basilar artery occlusion (BAO). We aimed to develop a new angiographic collateral grading system for predicting 90-day functional outcomes of acute BAO after EVT. A prospectively registered consecutive cohort of acute BAO patients treated with EVT in our center during a 6-year period was reviewed. The angiographic collateral grading system for BAO (ACGS-BAO) included 4 grades for poor (grade 1-2), intermediate (grade 3), and good (grade 4) collateral statuses. First, the independent association of ACGS-BAO with 90-day functional independence (mRS ≤ 2), favorable outcome (mRS ≤ 3), and death was evaluated by multivariable logistic regression model; then, the heterogeneity in the effects of ACGS-BAO on 90-day outcomes was explored among the subgroups stratified by age, time window, stroke severity, and etiology. Finally, the interobserver agreement of ACGS-BAO was assessed by weighted kappa statistic. Of 173 patients included in this study, 62 (35.8%), 83 (48.0%), and 36 (20.8%) achieved 90-day functional independence, favorable outcome, and death, respectively. Multivariable logistic analyses showed that ACGS-BAO was independently associated with functional independence (OR = 2.07, 95% CI = 1.05-4.07) and favorable outcome (OR = 1.84, 95% CI = 1.02-3.43) but not related to death (OR = 0.78, 95% CI = 0.37-1.64). Similar effects of ACGS-BAO on 90-day outcomes were seen across all subgroups (P > 0.10 for all interactions). The interobserver agreement of ACGS-BAO was very high (weighted kappa = 0.96, 95% CI = 0.93-0.99). The ACGS-BAO is an angiographic tool with excellent interobserver reliability that can be used to predict the 90-day outcome of acute BAO treated by EVT. Nevertheless, our findings are still needed to be confirmed in a prospective multicenter study before clinical application.

Predictive Factors and Nomogram to Evaluate the Risk of Symptomatic Intracerebral Hemorrhage for Stroke Patients Receiving Thrombectomy

BACKGROUND

Symptomatic intracerebral hemorrhage (sICH) is a severe complication of mechanical thrombectomy (MT). This study is to identify predictive factors and create a nomogram to evaluate the risk of sICH after MT treatment.

METHODS

We conducted a retrospective analysis on 127 consecutive stroke patients treated by MT therapy. We evaluated multiple predictive factors for the incidence of sICH using univariate and multivariate logistic regressions. Based on the identified and other possible factors, a nomogram was constructed to predict the risk of sICH.

RESULTS

We identified several predictive factors for sICH in the univariate analysis, including thrombectomy maneuvers >3 (odds ratio [OR], 4.42; 95% confidence interval [CI], 1.25-15.6; P = 0.0211), admission blood glucose (OR, 1.29; 95% CI, 1.13-1.48; P = 0.0002), diabetes mellitus (OR, 4.44; 95% CI, 1.64-12.0; P = 0.0033), and admission National Institutes of Health Stroke Scale (NIHSS) score (OR, 1.05; 95% CI, 1.01-1.10; P = 0.0263). The multivariate analysis showed that admission NIHSS score and blood glucose significantly affected the prognosis. Moreover, the proposed nomogram showed reliable identification ability with an area under the curve of 0.82 (95% CI, 0.71-0.93), specificity of 0.745, sensitivity of 0.762, accuracy of 0.748, and negative predictive value of 0.941.

CONCLUSIONS

Our study identified the admission NIHSS score and admission blood glucose level as predictive factors for sICH. Moreover, the proposed nomogram based on possible factors showed reliable predictive performance in evaluating the risk of sICH.

Posterior circulation tandem occlusions: Classification and techniques

BACKGROUND

Posterior circulation tandem occlusions are poorly characterized in current literature. Data regarding endovascular approaches and outcomes in this patient subgroup is extremely limited.

METHODS

We conducted a retrospective analysis of a prospectively maintained database and identified 17 patients with posterior circulation tandem occlusions who underwent mechanical thrombectomy between 2014 and 2019.

RESULTS

Of 17 patients with posterior circulation tandem occlusion, the mean age was 55.76 ± 11.8 with 35.3% female. The mean NIHSS score on presentation was 17.2 ± 9.2. Tissue plasminogen activator was administered in 7 (41.2%) patients, stent-retrievers alone were used in 2 (11.8%), aspiration catheters alone were used in 2 (11.8%), a combination was used 12 (70.6%), and a self-expandable stent in 5 (29.4%). The mean number of device passes was 2.24 ± 2.02, recanalization failure occurred in 4 (23.5%) patients, the mean time from stroke onset to puncture was 6.9 ± 2.4 h, and the mean time from puncture to recanalization was 59.3 ± 26.6 min. Postprocedural symptomatic ICH occurred in 1 (5.9 %) patient, periprocedural ICH/SAH occurred in 2 (11.8%), periprocedural distal emboli occurred in 0 (0%), periprocedural vessel dissection occurred in 1 (5.9%), and periprocedural vessel perforation occurred in 1 (5.9%) patient. TICI score>2b was achieved in 13 (76.5%) patients. An improvement in NIHSS>3 at discharge occurred in 10 (58.8%) patients, and good outcomes (mRS score < 2) occurred in 7 (41.2%). The mean length of stay was 11.6 ± 12.2 days, and the mortality rate was 41.2%.

CONCLUSION

Endovascular intervention with mechanical thrombectomy is safe and feasible in patients with posterior circulation tandem occlusions.

Predictors of Favorable Outcome after Endovascular Thrombectomy in MRI: Selected Patients with Acute Basilar Artery Occlusion

BACKGROUND AND PURPOSE

Clinical outcomes after endovascular treatment for acute basilar artery occlusions need further investigation. Our aim was to analyze predictors of a 90-day good functional outcome defined as mRS 0-2 after endovascular treatment in MR imaging-selected patients with acute basilar artery occlusions.

MATERIALS AND METHODS

We analyzed consecutive MR imaging-selected patients with acute basilar artery occlusions endovascularly treated within the first 24 hours after symptom onset. Successful and complete reperfusion was defined as modified TICI scores 2b-3 and 3, respectively. Outcome at 90 days was analyzed in univariate and multivariate analysis regarding baseline patient treatment characteristics and periprocedural outcomes.

RESULTS

One hundred ten patients were included. In 10 patients, endovascular treatment was aborted for failed proximal/distal access. Overall, successful reperfusion was achieved in 81.8% of cases (n = 90; 95% CI, 73.3%-88.6%). At 90 days, favorable outcome was 31.8%, with a mortality rate of 40.9%; the prevalence of symptomatic intracranial hemorrhage within 24 hours was 2.7%. The median time from symptom onset to groin puncture was 410 minutes (interquartile range, 280-540 minutes). In multivariable analysis, complete reperfusion (OR = 6.59; 95% CI, 2.17-20.03), lower pretreatment NIHSS (OR = 0.77; 95% CI, 0.64-0.94), the presence of posterior communicating artery collateral flow (OR = 2.87; 95% CI, 1.05-7.84), the absence of atrial fibrillation (OR = 0.18; 95% CI, 0.03-0.99), and intravenous thrombolysis administration (OR = 2.75; 95% CI, 1.04-7.04) were associated with 90-day favorable outcome.

CONCLUSIONS

In our series of MR imaging-selected patients with acute basilar artery occlusions, complete reperfusion was the strongest predictor of a good outcome. Lower pretreatment NIHSS, the presence of posterior communicating artery collateral flow, the absence of atrial fibrillation, and intravenous thrombolysis administration were associated with favorable outcome.

Endovascular treatment combined with vertebral artery endarterectomy for patients with acute tandem vertebrobasilar artery occlusion

PURPOSE

To evaluate the safety and efficacy of endovascular treatment combined with vertebral artery endarterectomy in patients with acute tandem vertebrobasilar artery occlusion.

METHODS

From April 2017 to March 2019, three patients with acute basilar artery occlusion combined with ostial vertebral occlusion in our institution were enrolled in the study. They underwent endovascular treatment combined with vertebral artery endarterectomy. The clinical, technical and functional outcomes of the patients were retrospectively analysed.

RESULTS

All three patients in the study underwent complete recanalization. The modified Thrombolysis in Cerebral Infarction (mTICI) grade was 2b/3 in all patients. The modified Rankin Scale (mRS) score was 0-2 for the three patients at 3 months. Follow-up CT scans revealed no cerebral haemorrhage, and no patients died during follow-up. All patients achieved good clinical outcomes after the combined treatment.

CONCLUSION

Endovascular treatment combined with vertebral artery endarterectomy is a feasible method to treat patients with acute basilar artery occlusion combined with ostial vertebral occlusion, especially when the guidewire cannot pass through the ostium of the dominant vertebral artery occlusion.

A Pre-Intervention 4-Item Scale for Predicting Poor Outcome Despite Successful Recanalization in Basilar Artery Occlusion

Poor outcome despite successful recanalization is a relatively common occurrence after endovascular therapy (EVT) in acute intracranial large vessel occlusion. We aimed to develop a simple pre-intervention scale with readily available indicators for predicting the 90-day poor outcome in acute basilar artery occlusion (BAO) patients with successful recanalization after EVT. A prospectively registered consecutive cohort of acute BAO patients treated with EVT in a tertiary stroke center during a 6-year period was reviewed. Poor outcome despite successful recanalization was defined as a 90-day mRS of > 3 despite a post-intervention mTICI of ≥ 2b. A logistic regression analysis was employed to develop the predictive scale. The performance of the scale was estimated by ROC curve and Hosmer-Lemeshow test. Poor outcome was observed in 48 of 109 patients included in this study. The proposed scale consisted of four selected pre-intervention predictors, including the NIHSS score, Pons-Midbrain Index (PMI), bilateral thalamic infarction, and Basilar Artery on Computed Tomography Angiography (BATMAN) collateral score. The 4-item scale revealed good discrimination with an area under curve of 0.83 (95% CI = 0.75-0.90) and acceptable calibration assessed by Hosmer-Lemeshow test (P = 0.48). The optimal cutoff value of the scale (range 0-5 points) was ≥ 3 points with 77% sensitivity, 80% specificity, and 79% accuracy. As a pre-intervention predictive model, the 4-item scale has promising predictive value for poor outcome despite successful recanalization in BAO patients treated with EVT. Nevertheless, external validation with blinded outcome is still needed to confirm its performance before clinical application.

Stroke patients treated by thrombectomy in real life differ from cohorts of the clinical trials: a prospective observational study

Background

Randomized controlled trials (RCTs) demonstrated efficacy and safety of endovascular treatment (ET) in anterior circulation large vessel occlusions (LVO). We aimed at investigating how stroke patients treated by thrombectomy in clinical practice and their outcome compare to cohorts and results of thrombectomy trials.

Methods

In a prospective study, we consecutively included stroke patients treated by thrombectomy (2015–2017). Baseline characteristics, procedural and outcome data were analyzed. Outcome was assessed by modified Rankin Scale (mRS) at 90 days. Ordinal regression analysis was performed to identify predictors of outcome.

Results

Thrombectomy was applied in 264 patients (median 75 years, 49.6% female). Median baseline National Institutes of Health Stroke Scale (NIHSS) was 16, 58.0% received concomitant intravenous thrombolysis, 62.1% were referred from external hospitals. Median Alberta Stroke Program Early CT Score (ASPECTS) was 7. Successful recanalization (modified Thrombolysis in Cerebral Infarction Score, mTICI 2b/3) was achieved in 72.0%. Symptomatic intracranial hemorrhage (sICH) occurred in 4.5%. Independent outcome (mRS 0–2) was achieved in 26.2%, poor outcome (mRS 5–6) in 49.2%. Only 33.5% met the stringent enrolment criteria of previous RCTs. Lower age, baseline NIHSS, pre-stroke mRS, higher ASPECTS, and successful recanalization were independent predictors of favourable outcome.

Conclusions

The majority of stroke patients treated by ET in clinical practice would not have qualified for randomization in prior RCTs. Outcome in real-life patient cohorts is worse than in the highly selected cohorts from randomized trials, while rates of successful recanalization, sICH and outcome predictors are the same. Our findings support ET in broader patient populations than in the RCTs and may improve treatment decision in individual stroke patients with LVO in clinical practice.

Mechanical Thrombectomy for Posterior Circulation Occlusion: A Comparison of Outcomes with the Anterior Circulation Occlusion - A Meta-Analysis

Aim: There is no randomized controlled trial to compare the effectiveness and safety of mechanical thrombectomy (MT) to intravenous thrombolysis in patients with posterior circulation occlusion (PCO). Hence, we firstly performed a meta-analysis to investigate the outcomes of MT in PCO and then compared these outcomes to anterior circulation occlusion (ACO) to provide fundamental data to further studies.

Methods: We searched the PubMed, EMBASE, and Cochrane Library from dates of inception to June 2019 for relevant studies. Outcomes including functional independence at 90 days, successful recanalization, mortality, symptomatic intracranial hemorrhage (sICH), and futile recanalization were extracted.

Results: Seven studies involving 474 patients with PCO thrombectomy were analyzed. There was a lower rate of functional independence at 90 days and a higher rate of mortality after thrombectomy in PCO versus ACO (odds ratios (OR) 0.72; 95% confidence interval (CI) 0.57–0.90; OR 2.03; 95% CI 1.30–3.18). Recanalization rates were comparable (OR 1.01; 95% CI 0.62–1.65), but a higher futile recanalization rate was found in basilar artery occlusion (BAO) (OR 1.75; 95% CI 1.30–2.37). There was a lower rate of sICH in MT for patients with PCO versus ACO (OR 0.54; 95% CI 0.29–0.99).

Conclusions: We found that the outcomes of MT for patients with PCO were poorer than with ACO. On the other hand, MT appears to have lower rates of sICH and to increase successful recanalization. Given the high recanalization rate, MT may serve as an adjunct to standard treatment. The key point to improve outcomes is recognizing reliable factors associated with futile recanalization and optimizing the results of MT. But in view of the different characteristics of posterior circulation stroke and anterior circulation stroke, the results are far from robust.

Endovascular Treatment of Acute Ischemic Stroke

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

Recanalization is the Key for Better Outcome of Thrombectomy in Basilar Artery Occlusion

PURPOSE

Patients with basilar artery occlusion (BAO) were excluded from previous randomized controlled trials (RCTs) of endovascular treatment (ET) for acute ischemic stroke, but are commonly treated in clinical practice. This study aimed at analyzing predictors of functional outcome of ET in patients with BAO to improve patient selection for ET.

METHODS

Consecutive patients with BAO who received ET over a 2-year time period were prospectively studied. Baseline characteristics, procedural and outcome data were evaluated. Outcome was assessed by the modified Rankin Scale (mRS) 90 days after stroke. Multivariate regression analyses were performed to identify predictors of outcome across the range of the mRS, of poor outcome (mRS 5-6) and independent outcome (mRS 0-2).

RESULTS

A total of 39 patients with BAO (median age: 75 years, 67% male) were included. Median baseline National Institutes of Health Stroke Scale (NIHSS) score was 24. Intravenous thrombolysis therapy (IVT) was administered in 56%. Successful recanalization assessed by a modified thrombolysis in cerebral infarction (TICI) score ≥2b was achieved in 82%. Independent outcome was observed in 30% of patients with successful recanalization, but in no patient with failed recanalization. Poor outcome was observed in 47% and 86%, respectively. Successful recanalization was associated with lower scores on the mRS at 90 days (p = 0.035), and failed recanalization was associated with an odds ratio of 13.6 for poor outcome (p = 0.036).

CONCLUSION

Reperfusion is the major predictor of functional outcome in BAO in clinical practice. Failed recanalization resulted in a 13-fold increase of the risk of poor outcome. Successful recanalization is crucial to achieve a better functional outcome in BAO.

Endovascular treatment versus standard medical treatment for vertebrobasilar artery occlusion (BEST): an open-label, randomised controlled trial

BACKGROUND

Previous randomised trials have shown an overwhelming benefit of mechanical thrombectomy for treating patients with stroke caused by large vessel occlusion of the anterior circulation. Whether endovascular treatment is beneficial for vertebrobasilar artery occlusion remains unknown. In this study, we aimed to investigate the safety and efficacy of endovascular treatment of acute strokes due to vertebrobasilar artery occlusion.

METHODS

We did a multicentre, randomised, open-label trial, with blinded outcome assessment of thrombectomy in patients presenting within 8 h of vertebrobasilar occlusion at 28 centres in China. Patients were randomly assigned (1:1) to endovascular therapy plus standard medical therapy (intervention group) or standard medical therapy alone (control group). The randomisation sequence was computer-generated and stratified by participating centres. Allocation concealment was implemented by use of sealed envelopes. The primary outcome was a modified Rankin scale (mRS) score of 3 or lower (indicating ability to walk unassisted) at 90 days, assessed on an intention-to-treat basis. The primary safety outcome was mortality at 90 days. Secondary safety endpoints included the rates of symptomatic intracranial haemorrhage, device-related complications, and other severe adverse events. The BEST trial is registered with ClinicalTrials.gov, NCT02441556.

FINDINGS

Between April 27, 2015, and Sept 27, 2017, we assessed 288 patients for eligibility. The trial was terminated early after 131 patients had been randomly assigned (66 patients to the intervention group and 65 to the control group) because of high crossover rate and poor recruitment. In the intention-to-treat analysis, there was no evidence of a difference in the proportion of participants with mRS 0-3 at 90 days according to treatment (28 [42%] of 66 patients in the intervention group vs 21 [32%] of 65 in the control group; adjusted odds ratio [OR] 1·74, 95% CI 0·81-3·74). Secondary prespecified analyses of the primary outcome, done to assess the effect of crossovers, showed higher rates of mRS 0-3 at 90 days in patients who actually received the intervention compared with those who received standard medical therapy alone in both per-protocol (28 [44%] of 63 patients with intervention vs 13 [25%] of 51 with standard therapy; adjusted OR 2·90, 95% CI 1·20-7·03) and as-treated (36 [47%] of 77 patients with intervention vs 13 [24%] of 54 with standard therapy; 3·02, 1·31-7·00) populations. The 90-day mortality was similar between groups (22 [33%] of 66 patients in the intervention vs 25 [38%] of 65 in the control group; p=0·54) despite a numerically higher prevalence of symptomatic intracranial haemorrhage in the intervention group.

INTERPRETATION

There was no evidence of a difference in favourable outcomes of patients receiving endovascular therapy compared with those receiving standard medical therapy alone. Results might have been confounded by loss of equipoise over the course of the trial, resulting in poor adherence to the assigned study treatment and a reduced sample size due to the early termination of the study.

FUNDING

Jiangsu Provincial Special Program of Medical Science.

Significance of angiographic clot meniscus sign in mechanical thrombectomy of basilar artery stroke

Introduction

The relationship between the occlusive clot morphology and the efficacy of mechanical thrombectomy (MT) in basilar artery occlusion (BAO) is not well known. Our aim was to evaluate the clinical significance of the clot meniscus sign in patients with acute BAO.

Methods

89 patients with acute BAO who underwent MT were retrospectively analyzed. The clot meniscus sign was defined as meniscoid/tram-track like antegrade side-wall contrast opacification of the thrombus. Patients were assigned to two groups based on the presence of the clot meniscus sign. The treatment and clinical outcomes were compared.

Results

The clot meniscus sign was diagnosed in 62.9% (53/89) of the patients. The meniscus sign (+) group showed a shorter procedure time (55 vs 85 min; p=0.045), higher rate of successful recanalization (89.3% vs 63.6%, p=0.004), higher incidence of first pass effect (32.1% vs 6.1%, p=0.004), and lower number of passes (2 vs 3; p=0.042) when compared with the meniscus sign (−) group. The procedure time (OR 0.972, 95% CI 0.962 to 0.992; p=0.003) and clot meniscus sign (OR 7.920, 95% CI 1.769 to 35.452; p=0.007) were independent predictors of successful recanalization.

Conclusion

The clot meniscus sign is related to high first pass effect and short procedure time and is a reliable predictor of successful recanalization in patients with acute BAO.

Predictors of Outcome After Endovascular Thrombectomy in Acute Basilar Artery Occlusion and the 6hr Time Window to Recanalization

Background and Purpose: Decision algorithms for large vessel occlusions in the anterior circulation remain unconfirmed for acute basilar artery occlusion (aBAO). The aim of this study was to investigate procedural parameters, patient characteristics, functional outcome, and survival in dependency of the time window to recanalization from symptom onset. Furthermore predictors of outcome were identified.

Materials and Methods: Retrospectively 231 patients with aBAO treated with endovascular treatment (EVT) between November 2008 and February 2019 were identified in a prospectively maintained single center stroke database. Baseline characteristics such as age, cardiovascular risk factors, NIHSS at admission, pre-interventional PC-ASPECTS, periprocedural parameters such as time to recanalization, duration of treatment, extent of reperfusion, collateral status, and occlusion patterns, as well as post-interventional 24 h NIHSS and post-interventional ICH were evaluated. Target variables were mRS at 90 days and mortality over 90 days.

Results: Good outcome (mRS 0–2) was attained in 29.5% (n = 68) of patients, overall mortality was 36.8% (n = 85). In mulitivariate analyses patients with time to reperfusion beyond 6 h had a more than half fold decreased chance of good outcome [OR 0.47 95% CI (0.23–0.95) p < 0.05]. The odds for good outcome were reduced by almost 2/3 if post-interventional imaging revealed intracerebral hemorrhage [OR 0.28 95% CI (0.08–0.98)]. Unfavorable outcome was noted in 100% (n = 14) of patients with symptomatic ICH. Risk for death was reduced by more than 80% if collaterals were present [0.16 95% CI (0.03–0.87)] and if recanalization was successful (TICI 2b-3) [OR 0.19 95% CI (0.05–0.78)]. The odds for survival were 5-fold higher in patients with no post-interventional hemorrhages present [OR 5.35 95% CI (2.2–1.58)].

Conclusion: This study might contribute to explaining the ambiguous findings regarding the validity of the 6 h time window in aBAO, suggesting that collateral status impacts the odds of survival in the time window to recanalization beyond 6 h. In our study recanalization within 6 h from symptom onset was associated with good outcome. Successful recanalization (TICI 2b-3a) was necessary for good outcome and survival, post-interventional ICH was highly associated with unfavorable outcome. This might ease the decision making for EVT.

Blood pressure characteristics in patients with acute basilar artery occlusion undergoing endovascular thrombectomy

Acute basilar artery occlusion (BAO) is a rare but potentially life-threatening neurological condition. While endovascular therapy (EVT) has been shown to improve outcome, there is limited knowledge about prognostic factors beyond early recanalization. We studied whether blood pressure (BP) exceeds or falls below suggested thresholds during intervention and whether these changes are associated with complications and outcome. BP measurements mostly with one-minute intervals were available in 39 patients. An individual systolic blood pressure (SBP) reference value was defined as the median of the first five intra-procedural measurements. Half of the patients (51.3%) received drugs for BP augmentation and two a BP lowering drug (5.1%). Thrombolysis in cerebral infarction grade 2b and 3 (TICI) was achieved in 29 (74.4%) and 23 patients (58.9%) had good outcome at three months. We observed a continuous intra-procedural increase of median SBP (+11%) and mean arterial pressure (MAP, +10%, both p < 0.001), and a unique temporal pattern of intermittent peaks and troughs. Successful recanalization was more common in patients whose intra-procedural duration with SBP under 140 mmHg was shorter (p = 0.009). Patients with isolated tip of basilar artery (TBA) occlusion had significantly more BP excursion of 20% below the reference SBP and required more frequent use of sympathomimetic drugs compared to vertebrobasilar occlusion (p = 0.008 and p = 0.041, respectively). Brain hemorrhage was more prevalent in patients who experienced SBP excursions at least 20% above the individual reference value (p = 0.038) and a longer duration of time spent with SBP above 180 mmHg (p = 0.029). Patients with higher pre-procedural mean SBP had a greater chance of a good outcome (p = 0.03). This study using high resolution BP monitoring suggests a relationship between intra-procedural BP characteristics and recanalization, hemorrhagic complications and outcome in patients receiving EVT for acute posterior circulation cerebrovascular syndromes. Differences with regard to BP regulation during recanalization therapy for vertebrobasilar and TBA occlusion deserves further attention.

Mechanical thrombectomy for basilar artery occlusion: efficacy, outcomes, and futile recanalization in comparison with the anterior circulation

BACKGROUND

Performing mechanical thrombectomy (MT) in patients with basilar artery occlusion (BAO) is currently not evidence-based.

OBJECTIVE

To compare patients' outcome, relative merits of achieving recanalization, and predictors of futile recanalization (FR) between BAO and anterior circulation large vessel occlusion (ACLVO) MT.

METHODS

In the multicenter BEYOND-SWIFT registry (NCT03496064), univariate and multivariate (displayed as adjusted Odds Ratios, aOR and 95% confidence intervals, 95%-CI) outcome comparisons between BAO (N=165) and ACLVO (N=1574) were performed. The primary outcome was favorable outcome at 90 days (modified Rankin Scale, mRS 0-2). Secondary outcome included mortality, symptomatic intracranial hemorrhage (sICH) and FR. The relative merits of achieving successful recanalization between ACLVO and BAO were evaluated with interaction terms.

RESULTS

MT in BAO was more often technically effective and equally safe in regards to mortality and sICH when compared to ACLVO. When adjusting for baseline differences, there was no significant difference between BAO vs ACLVO regarding rates of favorable outcome (aOR 0.986, 95%-CI 0.553 - 1.758). However, BAO were associated with increased rates of FR (aOR 2.146, 95%-CI 1.267 - 3.633). Predictors for FR were age, stroke severity, maneuver count and intracranial stenting. No significant heterogeneity on the relative merits of achieving successful recanalization on several outcome parameters were observed when comparing BAO and ACLVO.

CONCLUSIONS

In selected patients, similar outcomes can be achieved in BAO and ACLVO patients treated with MT. Randomized controlled trials comparing patient selection and interventional strategies seem warranted to avoid FR.

TRIAL REGISTRATION NUMBER

NCT03496064.