Intravenous thrombolysis of basilar artery occlusion: predictors of recanalization and outcome

Abstract

Background and purpose: Basilar artery occlusion has a high mortality rate (85% to 95%) if untreated. We describe a large single-center cohort treated mostly with intravenous alteplase and heparin.

Methods: The cohort included 116 patients with angiography-verified basilar artery occlusion. We studied baseline characteristics, frequencies of recanalization and symptomatic intracranial hemorrhage, and 3-month outcome (modified Rankin Scale [mRS]).

Results: Thirty patients (25.9%) had mRS 0 to 2, 42 patients (36.2%) had moderate outcome (mRS, 0-3), 26 patients (22.4%) required daily help (mRS, 4-5), and 48 patients (41.4%) died. Eighteen patients (15.7%) developed symptomatic intracranial hemorrhage. In patients with post-treatment angiogram available (n=91), 59 patients (64.8%) had a complete or partial recanalization. Radiological location of basilar artery occlusion was known in 55 of 91 instances, and recanalization was associated directly with clot location at the top-of-basilar (odds ratio, 4.8 [1.1-22]; P=0.048). Independent outcome (mRS 0-2) was associated with lower age and National Institutes of Health Stroke Scale (NIHSS) score at baseline. Age, nil or minimal recanalization, and symptomatic intracranial hemorrhage were independently associated with fatal outcome. Sixteen of 71 patients (22.5%) who presented with coma eventually reached moderate outcome, and additional 8 patients (11.3%) progressed to mRS 4.

Conclusions: Whereas recanalization after intravenous thrombolysis strongly predicts survival and moderate outcome, therapeutic techniques should concentrate on clot location. Although most adverse baseline variables, age, symptom severity, but also coma are beyond control, it should not preclude thrombolysis, which may permit independent survival.