Endovascular treatment for stroke caused by occlusion of medium or distal vessels did not significantly improve disability outcomes or reduce mortality compared to best medical treatment alone, according to recent findings.

Published in The New England Journal of Medicine, the randomized DISTAL trial, conducted across 55 hospitals in 11 countries, enrolled 543 participants with isolated occlusions of medium or distal vessels within 24 hours of symptom onset. The primary outcome, disability at 90 days as measured by the modified Rankin Scale, showed no significant difference between EVT plus best medical treatment and best medical treatment alone (common odds ratio, 0.90; 95% confidence interval [CI], 0.67 to 1.22; P = 0.50).

Participants had a median NIHSS score of 6 (IQR, 5–9) at admission, and 65.4% received intravenous thrombolysis. The most common occlusion locations were the M2 segment (44.0%), M3 segment (26.9%), P2 segment (13.4%), and P1 segment (5.5%). Symptomatic intracranial hemorrhage occurred in 5.9% of the EVT plus best medical treatment group versus 2.6% in the best medical treatment group (odds ratio, 2.38; 95% CI, 0.44 to 6.14), while all-cause mortality at 90 days was 15.5% and 14.0%, respectively (odds ratio, 1.17; 95% CI, 0.71 to 1.90).

"In persons with stroke with occlusion of medium or distal vessels, EVT did not result in a lower level of disability or a lower incidence of death than best medical treatment alone," said Marios Psychogios, M.D. from the Department of Diagnostic and Interventional Neuroradiology, University Hospital Basel, Basel, Switzerland.

Although successful reperfusion was achieved in 71.7% of EVT-treated patients, this rate was lower than expected. Researchers noted that new techniques or devices may be needed to improve EVT outcomes for these occlusions.

The study was funded by the Swiss National Science Foundation, Gottfried und Julia Bangerter-Rhyner-Stiftung, and several medical device companies including Medtronic, Stryker Neurovascular, Phenox, Rapid Medical, and Penumbra. Further research may be warranted to identify patient subgroups that could benefit from EVT based on imaging selection and treatment strategies.

Disclosures can be found in the study.