Shaban, Amir

Abstract Background Recent trials have furthered uncertainty regarding the endovascular benefit for medium vessel occlusions (MeVO). Stent retrievers (SR) were employed in the first attempt in most interventional arm participants. We sought to compare outcomes in acute MCA M2 occlusions between frontline aspiration and SR, and to delineate procedural and anatomical covariates associated with differential treatment effect. Methods Retrospective analysis of a multicenter stroke thrombectomy cohort identified cases of MT for M2 occlusions. Unmatched and propensity score-matched (PSM) cohorts were generated comparing frontline aspiration to standalone and combined SR. The primary outcome was functional independence (mRS 0–2) at 90 days. Recanalization, symptomatic intracranial hemorrhage (sICH), mortality, and the effect of M2 laterality, division occlusion and procedure time were assessed. Results About 1734 patients with M2 occlusions underwent either frontline aspiration (n = 711) or SR/combined (n = 958) thrombectomy between 2013 and 2024. PSM analysis favored aspiration for functional independence (49.9% vs 44.0%, OR 1.27 (1.03–1.57)), complete recanalization (61.2% vs 48.7%, OR 1.66 (1.34–2.05)), complete first pass effect (35.0% vs 27.6%, OR 1.42 (1.13–1.78)), and sICH (3.5% vs 6.2%, OR 0.55 (0.33–0.91)), with no difference in mortality. Frontline aspiration had significantly shorter procedural times (median 28 [IQR 15–49.5] vs 51 [IQR 35–78] minutes; p < 0.001). For every minute increase in procedure time, the probability of functional independence decreased significantly (p < 0.001) less with frontline aspiration (0.35%) compared to SR/combined (1.61%). Conclusion Frontline aspiration for M2 occlusions resulted in better clinical and angiographic outcomes compared to SRs. Future trials for MeVO with a focus on contact aspiration thrombectomy may succeed where recent trials have failed.

Background Endovascular thrombectomy (EVT) has transformed acute ischemic stroke (AIS) care, with onset-to-puncture (OTP) time widely recognized as a critical determinant of outcome. However, emerging evidence suggests that in-hospital procedure time (PT)—from arterial puncture to final recanalization—may have an equally or more significant impact. This study examines the relative contribution of PT versus OTP to functional outcomes in patients with AIS undergoing EVT. Methods A retrospective analysis was conducted of 6644 patients with AIS treated at 44 international stroke centers from the Stroke Thrombectomy and Aneurysm Registry (STAR; 2016–2023). Multivariable regression, time-equivalence analysis, and marginal effects modeling were used to assess associations between PT, OTP, and 90-day modified Rankin Scale (mRS) outcomes. Centers were stratified by procedural efficiency and compared using propensity score matching (PSM). Mediation analysis evaluated whether PT accounted for inter-center differences. Results PT and OTP were independently associated with functional outcomes; however, PT had a significantly stronger effect (adjusted OR for mRS 0–2: PT=0.56 vs OTP=0.96 per hour). Each 5 min increase in PT was equivalent to 78–100 min of additional OTP in outcome impact. Centers with faster average PT had higher rates of functional independence (number needed to treat (NNT)=10), fewer complications, and lower symptomatic intracranial hemorrhage rates. PT significantly mediated the relationship between center tier and outcomes (Sobel’s P<0.001). Conclusion While minimizing OTP remains important, PT exerts a greater influence on outcomes after EVT. Procedural efficiency should be emphasized in stroke systems of care and included in center performance metrics to improve patient outcomes.

Background The effectiveness of endovascular thrombectomy (EVT) for low Alberta Stroke Program Early CT score (ASPECTS) stroke patients with occlusion of the second segment of the middle cerebral artery (M2) is unclear. Methods This was a multicenter retrospective study. Patients with M1 or M2 occlusions and low ASPECTS (<6) who underwent successful EVT (modified treatment in cerebral ischemia score of 2b or higher) were included. Primary outcome was futile EVT reperfusion (defined as 90-day modified Rankin scale of 5 or 6). Other outcomes of interest include acceptable outcomes (modified Rankin scale of 3 or less) and intracranial hemorrhage (ICH), and all-cause 90-day mortality. Outcomes for M1 patients were compared to M2 patients with multivariable logistic regression models accounting for potential confounders. Results 173 patients with M1 or M2 occlusions and low ASPECTS (<6) who underwent successful EVT were identified. After multivariable adjustments, M2 patients had significantly higher odds of futile reperfusion (OR 5.48 [95%CI 1.91 to 15.7], p = 0.002), lower odds of acceptable outcomes (OR 0.33 [95%CI 0.12 to 0.89], p = 0.028), and higher odds of all-cause mortality (OR 4.90 [95%CI 1.65 to 14.5], p = 0.004). These findings suggest that EVT's efficacy for low-ASPECTS stroke patients may be diminished for patients with M2 occlusions. M2 occlusion was not significantly associated with ICH. Conclusions Among low-ASEPCTS stroke patients who underwent successful EVT, those with M2 occlusions had significantly higher odds of poor outcome compared to those with M1 occlusions.

Background The contact aspiration (CA) technique is often used to perform endovascular thrombectomy (EVT) for acute ischemic stroke (AIS); however, rescue strategies are necessary if CA fails to achieve recanalization. This study investigates the outcomes of incorporating stent retriever (SR) thrombectomy in the rescue strategy following failed CA. Methods EVT patients with failed CA attempts were identified from a large multicenter registry and stratified by rescue technique: CA alone or incorporating SR in the rescue strategy. Outcomes included successful recanalization, 90-day functional outcomes (defined by the modified Rankin Scale (mRS) score), symptomatic intracranial hemorrhage (sICH), and 90-day mortality. Results Among 1885 patients with failed CA attempts, conversion to SR was associated with higher recanalization rates (85.2% vs 80.6%; p=0.03), higher rates of second-pass recanalization (31.2% vs 23.4%; p<0.001), and better 90-day outcomes (mRS 0–2: 35.2% vs 29.9%; p=0.04) when compared with repeated CA attempts. Trevo SRs showed higher odds of successful recanalization (adjusted odds ratio (aOR)=1.9; p=0.02), second-pass recanalization (aOR=1.7; p=0.01), and reduced odds of sICH (aOR=0.3; p=0.02). EmboTrap SRs were associated with higher odds of 90-day mortality (aOR=2.6; p=0.004) and sICH (aOR=2.9; p=0.04) and lower odds of recanalization (aOR=0.5; p=0.03). Conclusions Incorporating SR in the rescue strategy after a failed CA improves recanalization rates and functional outcomes. Trevo SRs demonstrated superior efficacy and safety when incorporated into the rescue strategy.

Background Whereas mechanical thrombectomy (MT) has become standard-of-care treatment for patients with salvageable brain tissue after acute stroke caused by large-vessel occlusions, the results of MT in patients with medium-vessel occlusions (MEVOs), particularly in the posterior cerebral artery (PCA), are not well known. Methods Using data from the international Stroke Thrombectomy and Aneurysm Registry (STAR), we assessed presenting characteristics and clinical outcomes for patients who underwent MT for primary occlusions in the P2 PCA segment. As a subanalysis, we compared the PCA MeVO outcomes with STAR's anterior circulation MeVO outcomes, namely middle cerebral artery (MCA) M2 and M3 segments. Results Of the 9812 patients in STAR, 43 underwent MT for isolated PCA MeVOs. The patients’ median age was 69 years (interquartile range 61–79), and 48.8% were female. The median NIH Stroke Scale score was 9 (range 6–17). After recanalization, 67.4% of patients achieved successful recanalization (modified treatment in cerebral infarction score [mTICI] ≥ 2b), with a first-pass success rate of 44.2%, and 39.6% achieved a modified Rankin score of 0–2 at 90 days. Nine patients (20.9%) had died by the 90-day follow-up. In comparison with M2 and M3 MeVOs, there were no differences in presenting characteristics among the three groups. Patients with PCA MeVOs were less likely to undergo intra-arterial thrombolysis (4.7% PCA vs. 10.1% M2 vs. 16.2% M3, p = 0.046) or to achieve successful recanalization (mTICI ≥ 2b, 67.4%, 86.7%, 82.3%, respectively, p < 0.001); however, there were no differences in the rates of successful first-pass recanalization (44.2%, 49.8%, 52.3%, respectively, p = 0.65). Conclusions We describe the STAR experience performing MT in patients with PCA MeVOs. Our analysis supports that successful first-pass recanalization can be achieved in PCA MEVOs at a rate similar to that in MCA MeVOs, although further study and possible innovation may be necessary to improve successful PCA MeVO recanalization rates.

Background Multiple randomized trials could not establish the noninferiority of endovascular thrombectomy (EVT) alone without preceding intravenous thrombolysis (IVT) or superiority of IVT followed by EVT in anterior circulation large‐vessel occlusion stroke. The role of prior IVT in posterior circulation large‐vessel occlusion remains controversial. Methods In this multicenter, retrospective study, patients with stroke with large‐vessel occlusion in the posterior circulation who received EVT alone or with IVT were selected from the stroke thrombectomy and aneurysm registry between 2013 and 2022. Effects of IVT followed by thrombectomy on favorable functional outcome (defined as modified Rankin scale≤3 at 90 days) and safety were investigated using multivariable logistic and linear regression models. Results Of the 588 included patients, 67% (n = 394) were treated with EVT alone and 29% (n = 170) with EVT after IVT, and 4% (n = 24) have missing values on this variable. Controlling for multiple confounding factors, IVT was not associated with a higher likelihood of favorable functional outcome at 90 days (odds ratio, 1.04 [95% CI, 0.52–2.09; P = 0.901). Thrombectomy alone did not show any safety advantages compared with those receiving IVT. Conclusion Similar functional outcomes and complication rates were seen in patients with posterior circulation large‐vessel occlusion treated with EVT alone versus EVT after IVT. Further prospective studies are required to determine the utility of IVT in posterior circulation stroke, especially in patients being directly admitted to thrombectomy centers.

BACKGROUND AND OBJECTIVES: First pass effect (FPE) is a metric increasingly used to determine the success of mechanical thrombectomy (MT) procedures. However, few studies have investigated whether the duration of the procedure can modify the clinical benefit of FPE. We sought to determine whether FPE after MT for anterior circulation large vessel occlusion acute ischemic stroke is modified by procedural time (PT). METHODS: A multicenter, international data set was retrospectively analyzed for anterior circulation large vessel occlusion acute ischemic stroke treated by MT who achieved excellent reperfusion (thrombolysis in cerebral infarction 2c/3). The primary outcome was good functional outcome defined by 90-day modified Rankin scale scores of 0–2. The primary study exposure was first pass success (FPS, 1 pass vs ≥2 passes) and the secondary exposure was PT. We fit-adjusted logistic regression models and used marginal effects to assess the interaction between PT (≤30 vs >30 minutes) and FPS, adjusting for potential confounders including time from stroke presentation. RESULTS: A total of 1310 patients had excellent reperfusion. These patients were divided into 2 cohorts based on PT: ≤30 minutes (777 patients, 59.3%) and >30 minutes (533 patients, 40.7%). Good functional outcome was observed in 658 patients (50.2%). The interaction term between FPS and PT was significant ( P = .018). Individuals with FPS in ≤30 minutes had 11.5% higher adjusted predicted probability of good outcome compared with those who required ≥2 passes (58.2% vs 46.7%, P = .001). However, there was no significant difference in the adjusted predicted probability of good outcome in individuals with PT >30 minutes. This relationship appeared identical in models with PT treated as a continuous variable. CONCLUSION: FPE is modified by PT, with the added clinical benefit lost in longer procedures greater than 30 minutes. A comprehensive metric for MT procedures, namely, FPE 30 , may better represent the ideal of fast, complete reperfusion with a single pass of a thrombectomy device.

Introduction: Acute ischemic stroke (AIS) patients often require multiple passes during mechanical thrombectomy (MT) to open the vessel. Yet, at times, even numerous passes are unsuccessful. This study aims to investigate the impact of the number of passes on the outcomes of patients who underwent failed MT. Methods: We used Data from the Stroke Thrombectomy and Aneurysm Registry (STAR) from 2013 to August 2023. Patients who underwent MT for ICA, M1, or M2 with unsuccessful recanalization (modified Thrombolysis in Cerebral Infarction ≤ 2a) were included. Primary outcome was 90- day modified Rankin Scale (mRS) 0-2. Secondary outcomes included any intracranial hemorrhage (ICH) and symptomatic ICH (sICH). Outcomes were compared among patients who received ≤ 2, 3, 4, and ≥ 5 MT passes. Results: 736 patients met inclusion criteria. 90-day mRS 0-2 was found to decrease with number of passes (Figure 1). Multivariate logistic regression analysis revealed that 3 passes (OR: 0.48, 95% CI: 0.23 -0.96, P-value: 0.04), 4 passes (OR: 0.46, 95% CI: 0.19 -1.03, P-value: 0.07), and ≥ 5 passes (OR: 0.22, 95% CI: 0.08 -0.50, P-value: <0.001) were associated with lower odds of mRS 0-2 compared to ≤ 2 passes. However, there were no significant differences between groups in ICH, sICH, or 90-day mortality. Conclusion: The number of passes affects functional outcomes among stroke patients who underwent failed MT.

Introduction: Recent randomized control trials suggested that mechanical thrombectomy (MT) was associated with good functional outcomes after acute ischemic stroke (AIS) due to large vessel occlusion (LVO) in patients presenting with low Alberta Stroke Program Early CT Score (ASPECTS) (defined as ASPECTS 2-5). The aim of this study is to develop and validate a stroke prediction tool for outcome in MT for AIS patients with low ASPECTS using data from an ongoing international multicenter registry, the Stroke Thrombectomy and Aneurysm Registry (STAR). Methods: 236 AIS patients with low ASPECTS caused by LVO who undertook MT between January 2010 and December 2022 were retrospectively investigated. Univariate and multivariate logistic regression results were used to screen model predictors and construct nomograms of 90-day modified Rankin Scale scores (mRS) 0-3. The performance of the model was detected by using receiver operating characteristic analysis. The bootstrap resampling method was considered internal validation of the model. Results: Age (< 70 years), premorbid status (mRS 0), National Institutes of Health Stroke Scale (NIHSS) (< 20), and recanalization status after the MT (modified Thrombolysis in Cerebral Ischemia [mTICU] ≥2b) were related to 90-day mRS 0-3. Predictive score was calculated by adding 1 point for age (< 70 years), premorbid status (mRS 0), and NIHSS < 20 and 3 points for a mTICI ≥2b (ranging 0-6). 90-day mRS 0-3 was observed in 0% of patients with a score of 0 or 1, 6.3% with a score of 2, 17.7% with a score of 3, 22.2% with a score of 4, 45.7% with a score of 5, and 73.7% with a score of 6. The score showed relatively high performance in predicting 90-day mRS0-3 (area under the curve: 0.79 [95% CI 0.73-0.79] and 0.78 [95% CI 0.78-0.78] for derivation and validation cohorts, respectively). Conclusions: This study indicates the STAR score can be calculated with baseline and periprocedural characteristics to predict the 90-day outcome after MT in AIS patients with low ASPECTS.

Introduction: The outcomes of mechanical thrombectomy (MT) for patients with acute ischemic stroke (AIS) caused by medium vessel occlusions (MeVOs) in different vessels remains unknown. The aim of this study is to investigate MT outcomes in AIS patients with isolated MeVOs in different occluded vessel segments using the data from an ongoing international multicenter registry, the Stroke Thrombectomy and Aneurysm Registry (STAR). The aim of this study is to investigate MT outcomes in AIS patients with isolated MeVOs in different occluded vessel segments using the data from an ongoing international multicenter registry, the Stroke Thrombectomy and Aneurysm Registry (STAR). Methods: 110 AIS patients with MeVO who undertook MT between January 2010 and December 2022 were retrospectively investigated. MeVO was defined as isolated occlusion of the A2 or A3 (A23O) segment of the anterior cerebral artery, M3 segment of the middle cerebral artery (M3O), and P2 or P3 segment of the posterior cerebral artery (P23O). The primary outcome measure was a 90-day modified Rankin score (mRS) 0-2. The 90-day mRS 0-1, any intracranial hemorrhage, symptomatic intracranial hemorrhage, and 90-day mortality were used as secondary outcomes. Outcomes were compared between A23O, M3O, and P23O. Results: Median (interquartile range) age was 68.3 (58.4-76.0) years and 49 patients were female (46.7%). MeVO included 17 A23O (15.5%), 60 M3O (54.5%), and 33 P23O (30.0%).Compared to patients with A23O (17.7%), those with M3O (56.7%) and P23O (45.5%) had a higher proportion of 90-day mRS 0-2 (M3O, adjusted odds ratio 10.3, 95% confidence interval 1.71-62.2, p = 0.01; P23O adjusted odds ratio 8.86, 95% confidence interval 1.32-59.3, p =0.02). Other outcomes showed no significant differences. Conclusions: This study indicates A2O might be related to poorer outcomes compared to M3O and P23 in MT treatment for AIS patients due to isolated MeVO. Efforts should be aimed at improving outcomes following A23O to match those at other MeVO locations.