Endovascular Treatment of Medium Vessel Occlusion

Key Takeaways

• Among patients with medium-vessel occlusion stroke and moderate-to-severe deficits, thrombectomy was associated with a higher rate of functional independence at 90 days than medical management alone.
• Symptomatic intracranial hemorrhage was more frequent with thrombectomy, while 90-day mortality was numerically similar between groups.

Thrombectomy plus medical management, compared with medical management alone, was linked to higher 90-day functional independence in adults with acute ischemic stroke due to medium-vessel occlusion and moderate-to-severe deficits, reaching 58.6% versus 46.6% in a NEJM randomized trial. The open-label trial with blinded outcome assessment enrolled adults from 48 centers in China who presented within 24 hours after onset and had moderate-to-severe deficits, defined by a National Institutes of Health Stroke Scale score of at least 6. Functional recovery was more frequent with thrombectomy, alongside a higher rate of symptomatic intracranial hemorrhage.

This open-label randomized trial used blinded outcome assessment and assigned patients in a 1:1 ratio to thrombectomy plus medical management or medical management alone. Adults were eligible if they presented within 24 hours after stroke onset, had a medium-vessel occlusion, and had an NIHSS score of at least 6. Investigators randomized 280 patients to thrombectomy and 283 to control; the median age was 71 years, the median NIHSS score was 10, 42.8% were women, and 36.6% received intravenous thrombolysis. The prespecified primary outcome was 90-day modified Rankin Scale shift, but functional independence, defined as a score of 0 to 2, served as the primary outcome after the proportional-odds assumption was violated, consistent with the analytic plan.

For the final primary outcome, functional independence at 90 days was more likely with thrombectomy, with an adjusted rate ratio of 1.24 (95% confidence interval, 1.07 to 1.44; P=0.004). The investigators concluded that thrombectomy was associated with a greater likelihood of functional independence than medical management alone.

Safety findings showed symptomatic intracranial hemorrhage in 4.7% of the thrombectomy group and 2.2% of the control group. Ninety-day mortality was 11.1% with thrombectomy and 10.2% with medical management alone.