Endovascular thrombectomy for mild vertebrobasilar artery occlusion: a hierarchical win-ratio analysis

Background Endovascular thrombectomy (EVT) is used selectively for vertebrobasilar artery occlusion (VBAO), but its net value in mild deficits remains uncertain. We performed a hierarchical win-ratio analysis of EVT versus best medical management (BMM) in patients with acute VBAO and admission National Institutes of Health Stroke Scale (NIHSS) scores of 10 or less. Methods We performed a secondary analysis of a multicenter retrospective registry of acute VBAO with admission NIHSS scores of 10 or less. EVT plus BMM was compared with BMM alone in the overall cohort and in admission NIHSS strata of 0-5 and 6-10. The primary hierarchy ranked death status through common follow-up, 90-day modified Rankin Scale score, and symptomatic intracranial hemorrhage (sICH). All EVT-BMM pairs were compared sequentially and classified as an EVT win, BMM win, or tie. The adjusted analysis used stabilized inverse probability of treatment weighting (IPTW), with weights truncated at the 1st and 99th percentiles in a sensitivity analysis. Results The analysis included 1,232 patients: 428 underwent EVT and 804 received BMM. In the unweighted overall analysis, EVT had 146,674 wins, BMM had 149,958 wins, and 47,480 ties, yielding a WR of 0.98 (95% CI, 0.84-1.15; P = 0.749). After stabilized IPTW, the WR was 0.96 (95% CI, 0.80-1.14; P = 0.618). Sensitivity analyses did not show a robust overall association favoring EVT. In exploratory NIHSS-stratified analyses, the WR was 0.80 (95% CI, 0.61-1.05; P = 0.101) for NIHSS scores of 0-5 and 1.36 (95% CI, 1.10-1.68; P = 0.004) for scores of 6-10. Conclusions EVT was not associated with an overall net advantage over BMM in this hierarchical analysis. The exploratory signal among patients with admission NIHSS scores of 6-10 suggests that EVT may be feasible in selected patients and warrants confirmation in randomized trials; for patients with NIHSS scores of 0-5, EVT use should remain cautious and individualized.