Does stroke etiology influence outcome in the posterior circulation? An analysis of 107 consecutive acute basilar occlusion thrombectomies

OBJECTIVE Acute basilar artery occlusion (BAO) harbors a more guarded prognosis after thrombectomy compared with anterior circulation large-vessel occlusion. Whether this is a function of a greater proportion of atherosclerotic/ intrinsic lesions is not well studied. The authors aimed to elucidate the prevalence and predictors of intracranial intrinsic atherosclerotic disease in patients with acute BAO and to compare angiographic and clinical outcomes between patients with BAO secondary to embolic versus intrinsic disease. METHODS A prospectively maintained stroke database was reviewed for all patients presenting between January 2013 and December 2019 to a tertiary care academic comprehensive stroke center with acute, nontandem BAO. Patient data were extracted, subdivided by stroke mechanism and treatment modality (embolic [thrombectomy only] and intrinsic [thrombectomy + stenting]), and angiographic and clinical results were compared. RESULTS Of 107 patients, 83 (78%) had embolic occlusions (thrombectomy only) and 24 (22%) had intrinsic disease (thrombectomy + stenting). There was no significant difference in patient age, presenting National Institutes of Health Stroke Scale score, time to presentation, selected medical comorbidities (hypertension, hyperlipidemia, diabetes, and atrial fibrillation), prior stroke, and posterior circulation Alberta Stroke Program Early CT Score. Patients with intrinsic dis- ease were more likely to be active smokers (50% vs 26%, p = 0.04) and more likely to be male (88% vs 48%, p = 0.001). Successful recanalization, defined as a modified Thrombolysis in Cerebral Infarction (mTICI) grade of 2b or 3, was achieved in 90% of patients and did not differ significantly between the embolic versus intrinsic groups (89% vs 92%, p > 0.99). A 90-day good outcome (modified Rankin Scale [mRS] score 0-2) was found in 37% of patients overall and did not differ significantly between the two groups (36% vs 41%, p = 0.41). Mortality was 40% overall and did not significantly differ between groups (41% vs 36%, p = 0.45). CONCLUSIONS In the current study, demographic and clinical results for acute BAO showed that compared with intrinsic disease, thromboembolic disease is a more common mechanism of acute BAO, with 78% of patients undergoing thrombectomy alone. However, there was no significant difference in revascularization and outcome results between patients with embolic disease and those with intrinsic disease. https://thejns.org/doi/abs/10.3171/2021.4.FOCUS2189