World Stroke Organization The Paper of The Month – April
16 Apr 2025Distal and Medium Vessel Occlusions — Redefining the Boundaries of Mechanical Thrombectomy for Ischemic Stroke
Distal and Medium Vessel Occlusions — Redefining the Boundaries of Mechanical Thrombectomy for Ischemic Stroke
By Prof. Octavio Marques Pontes-Neto, MD, PHD – WSA Editor-in-Chief
This article is a commentary on the following: Endovascular Treatment for Stroke Due to Occlusion of Medium or Distal Vessels, N Engl J Med 2025;392:1374-84, DOI: 10.1056/NEJMoa2408954, https://www.nejm.org/doi/abs/10.1056/NEJMoa2408954
Commentary:
Over the past decade, endovascular thrombectomy (EVT) has revolutionized the treatment of acute ischemic stroke due to large-vessel occlusions (LVO). However, as the field advanced, a growing enthusiasm emerged for expanding EVT to more distal and medium-vessel occlusions (DMVO). Within the last few weeks, the publication of two pivotal randomized controlled trials—DISTAL and ESCAPE-MeVO—brings long-awaited clarity to this debate. Both trials reached the same realistic conclusion: EVT did not demonstrate clinical superiority over best medical management for DMVO.
The DISTAL trial, a pragmatic, multicenter RCT, enrolled 543 patients with occlusions in the M2–M4 segments of the MCA and other medium/distal cerebral arteries. Patients were randomized to EVT plus best medical treatment or best medical treatment alone. The results were conclusive: there was no difference in functional outcomes at 90 days (common odds ratio for improved modified Rankin Scale score, 0.90; 95% CI, 0.67–1.22; P = 0.50). Mortality and symptomatic intracranial hemorrhage rates were slightly higher in the EVT group but not statistically significant
Similarly, the ESCAPE-MeVO trial, conducted across five countries with 530 patients, showed no improvement in excellent functional outcome (mRS 0–1 at 90 days: 41.6% with EVT vs. 43.1% with usual care; P = 0.61) and an increased mortality in the EVT group (13.3% vs. 8.4%; HR, 1.82; 95% CI, 1.06–3.12).
Taken together, these trials mark an important inflection point. The enthusiasm for EVT in DMVO stroke, fueled by observational data and post hoc analyses, must now be questioned by high-level evidence showing no added benefit and potential harm. While prior studies suggested possible gains, these were often uncontrolled and vulnerable to selection bias. Both trials faced the inherent challenges of enrolling patients with mild-to-moderate strokes and older age—a group often underrepresented in earlier thrombectomy trials. Median ages in DISTAL and ESCAPE-MeVO were 77 and 75, respectively, and nearly half of all patients had NIHSS ≤5. Furthermore, both studies showed relatively low rates of reperfusion (~72–75%), raising questions about whether current techniques and devices are optimized for the intricacies of distal vasculature.
These trials do not close the door on EVT for DMVO strokes—but they caution against assuming its efficacy without rigorous testing. Future research must focus on refining patient selection, optimizing device technology for smaller vessels, and better understanding the natural history of these occlusions. Studies targeting select subgroups with disabling deficits, younger age, or favorable imaging profiles may still identify niches where EVT is beneficial. Meanwhile, the stroke community must adopt a more evidence-based restraint in clinical practice. Until further data emerge, best medical therapy, specially IV thrombolysis, remains the standard of care for patients with medium or distal vessel occlusions.
References:
- Psychogios M, Brehm A, Ribo M, et al.; DISTAL Investigators. Endovascular Treatment for Stroke Due to Occlusion of Medium or Distal Vessels. N Engl J Med. 2025 Apr 10;392(14):1374-1384.
- Goyal M, Ospel JM, Ganesh A, et al.; ESCAPE-MeVO Investigators. Endovascular Treatment of Stroke Due to Medium-Vessel Occlusion. N Engl J Med. 2025 Apr 10;392(14):1385-1395.
;
