Leptomeningeal collateral status predicts outcome after middle cerebral artery occlusion

Perfusion through leptomeningeal collateral vessels is a likely pivotal factor in the outcome of stroke patients. We aimed to investigate the effect of collateral status on outcome in a cohort of unselected, consecutive stroke patients with middle cerebral artery occlusion undergoing reperfusion therapy.

This retrospectively planned analysis was passed on prospectively collected data from 187 consecutive patients with middle cerebral artery occlusion admitted within 4.5 hours to one center and treated with intravenous thrombolysis alone (N = 126), mechanical thrombectomy alone (N = 5), or both (N = 56) from May 2009 to April 2014. Non-contrast CT (NCCT) and computed tomography angiography (CTA) were provided on admission and NCCT repeated at 24 hours. Collateral status was assessed based on the initial CTA. Hemorrhagic transformation was evaluated on the 24-hour NCCT and according to European Cooperative Acute Stroke Study (ECASS) criteria. Modified Rankin Scale score was assessed at 90 days, and mortality at 1 year.

At 90 days, median (IQR) modified Rankin Scale score in patients with poor collateral status was 4 (3-6) compared to 2 (1-4) in patients with good collateral status (P < .0001). Patients with poor collateral status were less likely to achieve a good 90-day outcome (modified Rankin Scale score 0-2) (Adjusted odds ratio 0.27, 95% CI: 0.09-0.86). During the first year, 40.9% of patients with poor collateral status died vs 18.2% of the remaining population (P = .001).

Leptomeningeal collateral status predicts functional outcome, mortality, and hemorrhagic transformation following middle cerebral artery occlusion.