Background: The optimal endovascular strategy for reperfusing distal medium-vessel occlusions (DMVO) remains unknown. This study evaluates angiographic and clinical outcomes of thrombectomy strategies in DMVO stroke of the posterior circulation. Methods: TOPMOST (Treatment for Primary Medium Vessel Occlusion Stroke) is an international, retrospective, multicenter, observational registry of patients treated for DMVO between January 2014 and June 2020. This study analyzed endovascularly treated isolated primary DMVO of the posterior cerebral artery in the P2 and P3 segment. Technical feasibility was evaluated with the first-pass effect defined as a modified Thrombolysis in Cerebral Infarction Scale score of 3. Rates of early neurological improvement and functional modified Rankin Scale scores at 90 days were compared. Safety was assessed by the occurrence of symptomatic intracranial hemorrhage and intervention-related serious adverse events. Results: A total of 141 patients met the inclusion criteria and were treated endovascularly for primary isolated DMVO in the P2 (84.4%, 119) or P3 segment (15.6%, 22) of the posterior cerebral artery. The median age was 75 (IQR, 62–81), and 45.4% (64) were female. The initial reperfusion strategy was aspiration only in 29% (41) and stent retriever in 71% (100), both achieving similar first-pass effect rates of 53.7% (22) and 44% (44; P =0.297), respectively. There were no significant differences in early neurological improvement (aspiration: 64.7% versus stent retriever: 52.2%; P =0.933) and modified Rankin Scale rates (modified Rankin Scale score 0–1, aspiration: 60.5% versus stent retriever 68.6%; P =0.4). In multivariable logistic regression analysis, the time from groin puncture to recanalization was associated with the first-pass effect (adjusted odds ratio, 0.97 [95% CI, 0.95–0.99]; P <0.001) that in turn was associated with early neurological improvement (aOR, 3.27 [95% CI, 1.16–9.21]; P <0.025). Symptomatic intracranial hemorrhage occurred in 2.8% (4) of all cases. Conclusions: Both first-pass aspiration and stent retriever thrombectomy for primary isolated posterior circulation DMVO seem to be safe and technically feasible leading to similar favorable rates of angiographic and clinical outcome.

Background Evidence supporting a potential benefit of thrombectomy for distal medium vessel occlusions (DMVOs) of the anterior cerebral artery (ACA) is, to the knowledge of the authors, unknown. Purpose To compare the clinical and safety outcomes between mechanical thrombectomy (MT) and best medical treatment (BMT) with or without intravenous thrombolysis for primary isolated ACA DMVOs. Materials and Methods Treatment for Primary Medium Vessel Occlusion Stroke, or TOPMOST, is an international, retrospective, multicenter, observational registry of patients treated for DMVO in daily practice. Patients treated with thrombectomy or BMT alone for primary ACA DMVO distal to the A1 segment between January 2013 and October 2021 were analyzed and compared by one-to-one propensity score matching (PSM). Early outcome was measured by the median improvement of National Institutes of Health Stroke Scale (NIHSS) scores at 24 hours. Favorable functional outcome was defined as modified Rankin scale scores of 0-2 at 90 days. Safety was assessed by the occurrence of symptomatic intracerebral hemorrhage and mortality. Results Of 154 patients (median age, 77 years; quartile 1 [Q1] to quartile 3 [Q3], 66-84 years; 80 men; 94 patients with MT; 60 patients with BMT) who met the inclusion criteria, 110 patients (median age, 76 years; Q1-Q3, 67-83 years; 50 men; 55 patients with MT; 55 patients with BMT) were matched. DMVOs were in A2 (82 patients; 53%), A3 (69 patients; 45%), and A3 (three patients; 2%). After PSM, the median 24-hour NIHSS point decrease was -2 (Q1-Q3, -4 to 0) in the thrombectomy and -1 (Q1-Q3, -4 to 1.25) in the BMT cohort (P = .52). Favorable functional outcome (MT vs BMT, 18 of 37 [49%] vs 19 of 39 [49%], respectively; P = .99) and mortality (MT vs BMT, eight of 37 [22%] vs 12 of 39 [31%], respectively; P = .36) were similar in both groups. Symptomatic intracranial hemorrhage occurred in three (2%) of 154 patients. Conclusion Thrombectomy appears to be a safe and technically feasible treatment option for primary isolated anterior cerebral artery occlusions in the A2 and A3 segment with clinical outcomes similar to best medical treatment with and without intravenous thrombolysis. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Zhu and Wang in this issue.

Background Mechanical thrombectomy (MT) is a safe and effective therapy for ischemic stroke. Nevertheless, very elderly patients aged ≥90 years were either excluded or under-represented in previous trials. It remains uncertain whether MT is warranted for this population or whether there should be an upper age limit. Methods We retrospectively reviewed 79 patients with stroke aged ≥90 years from three neurointerventional centers who underwent MT between 2013 and 2017. Good functional outcome was defined as modified Rankin scale (mRS) ≤2 and assessed at 90-day follow-up. Successful recanalization was graded by Thrombolysis in Cerebral Infarction Scale (TICI) ≥2 b. Feasibility and safety assessments included unsuccessful recanalization attempts (TICI 0), time from groin puncture to recanalization, symptomatic intracranial hemorrhage (sICH), mortality, and intervention-related serious adverse events. Results Only occlusions within the anterior circulation were included. Median time from groin puncture to recanalization was 39 min (IQR 25–57 min). The rate of successful recanalization (TICI ≥2 b) was 69.6% (55/79). Good functional outcome (mRS ≤2) at 90 days was observed in 16% (12/75) of patients. In-hospital mortality was 29.1% (23/79) and increased significantly at 90 days (46.7%, 35/75; p<0.001). sICH occurred in 5.1% (4/79) of patients. No independent predictor for good functional outcome (mRS ≤2) at 90 days was identified through logistic regression analysis. Conclusion MT in nonagenarians leads to high mortality rates and less frequently good functional outcome compared with younger patient cohorts in previous large randomized trials. However, MT appears to be safe and beneficial for a certain number of very elderly patients and therefore should generally not be withheld from nonagenarians.