Tanweer, Omar

Background Randomized trials have shown equivocal outcomes between a direct aspiration as first-pass technique (ADAPT) and stent retriever (SR) stroke thrombectomy, yet whether specific patient subgroups benefit differentially from one technique over the other remains unknown. Methods In this retrospective multicenter cohort study, patients with large vessel occlusion were included, and those who underwent ADAPT versus SR first-pass thrombectomy (either as standalone or combined with aspiration) were compared. The primary outcome was a composite of first-pass effect (FPE, modified Thrombolysis In Cerebral Infarction (mTICI) 2c or better with one attempt) with no symptomatic intracranial hemorrhage (sICH). A causal forest model was used to estimate the conditional average treatment effect (CATE) for each patient, with larger CATEs indicating that ADAPT is expected to be more advantageous. Patients were stratified by CATEs, and outcomes were compared between treatment groups. Results Among 6700 included patients, ADAPT (n=3695, 55%) was associated with a higher rate of FPE with no sICH (39.9% vs 26.9%; adjusted OR (aOR) 2.07, 95% CI 1.77 to 2.41, P<0.001). The causal forest identified significant treatment effect heterogeneity (interaction P<0.001), where ADAPT was more advantageous in more recent years and among patients with M1 occlusions presenting in earlier time windows. Low-CATE patients showed no statistically significant difference between techniques (aOR 0.91, 95% CI 0.57 to 1.45, P=0.70), while medium- and high-CATE patients demonstrated progressively larger ADAPT advantages (aOR 2.06, 95% CI 1.67 to 2.55, and aOR 2.99, 95% CI 2.24 to 3.98, respectively, both P<0.001). Conclusions ADAPT may be superior to SR for a majority of patients, particularly in recent years, and among patients with M1 occlusions presenting in earlier time windows.

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 &lt; 0.001). For every minute increase in procedure time, the probability of functional independence decreased significantly (p &lt; 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 AND OBJECTIVES: It remains unclear whether decompressive craniectomy (DC) is beneficial in patients who suffer symptomatic intracerebral hemorrhage (sICH) after acute ischemic stroke (AIS). We sought to study the effect of DC on functional outcomes in patients with sICH after AIS who underwent mechanical thrombectomy (MT). METHODS: Patients with AIS from anterior circulation large vessel occlusion who underwent MT and subsequently developed sICH were identified from the Stroke Thrombectomy and Aneurysm Registry database. The primary outcome was acceptable 90-day functional neurological outcome, defined as modified Rankin scale (mRS) 0-3. Multivariable logistic regression and propensity-score matching were used to identify and quantify risk factors. RESULTS: Of 464 patients identified with sICH after AIS after MT, 97 patients (20.9%) underwent DC. Patients who underwent DC were more likely to be female ( P < .001), younger ( P < .001), have a measured medical comorbidity, have higher baseline mRS ( P = .02), and have higher-grade hemorrhages ( P = .01). At 90 days, 14% of patients had the primary outcome of mRS 0-3 and 56% had died. The primary outcome was observed in 11 patients who underwent DC (11%) and 55 (15%) of those without DC (odds ratio [OR] 0.7, 95% CI 0.4-1.4, P = .40). DC did not affect mRS shift at 90 days ( P = .10) but was associated with lower mortality (OR 0.5, 95% CI 0.3-0.8, P = .01). Multivariable analysis demonstrated that DC decreased the odds of primary outcome (adjusted OR 0.2, 95% CI 0.02-0.9, P = .045), but did not affect mortality ( P = .94), mRS shift ( P = .50), or length of stay ( P = .90). Propensity-matched analysis similarly demonstrated that non-DC patients were more likely to achieve the primary outcome (24% vs 8%, P = .045). CONCLUSION: In patients with sICH after AIS after MT, those selected for DC had less favorable outcomes and similar rates of mortality at 90 days.

Background Flow-diverter stents (FDS) have become the standard of care for a wide range of intracranial aneurysms, but their efficacy/safety in the context of recurrent/recanalized aneurysms following stent-assisted coiling (SAC) is not well established. We evaluate the outcomes of FDS retreatment in a large multicenter cohort. Methods We retrospectively analyzed data from 118 patients across 22 institutions who underwent FDS retreatment for recurrent/persistent aneurysms after SAC (2008–22). The primary outcome was angiographic occlusion status at last follow-up, categorized as complete (100%), near-complete (90–99%), or incomplete (<90%) occlusion. Secondary outcomes included procedural complications and clinical outcomes measured by the modified Rankin Scale (mRS). Results A total of 118 patients (median age 57, 74.6% female) with median follow-up of 15.3 months were identified. Complete occlusion was achieved in 62.5% and near-complete occlusion in 25%. FDS deployment within the pre-existing stent was successful in 98.3% of cases. Major complications occurred in 3.4% of cases, including postoperative aneurysmal rupture with resultant mortality (1.6%) and thromboembolic events with long-term disability (1.6%). Favorable clinical outcomes (mRS 0–2) were observed in 95.1% of patients. Wider aneurysm neck diameter was a significant predictor of incomplete occlusion (adjusted OR (aOR) 1.23 per mm, P=0.044), with male sex trending towards association with non-occlusion (aOR 3.2, P=0.07), while baseline hypertension was associated with complete occlusion (aOR 0.32, P=0.048). Conclusions FDS treatment for recurrent/residual aneurysms after SAC represents a viable treatment option for these challenging cases with acceptable safety and reasonable occlusion rates, although lower than de novo FDS occlusion rates.

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.