Recanalization treatments in basilar artery occlusion—Systematic analysis

Background and aims: Basilar artery occlusion is a most devastating form of stroke, and the current practice is to reverse it with revascularization therapies. Pharmacological thrombolysis, intravenous or intraarterial, has been adjuncted or replaced with invasive, endovascular thrombectomy procedures. The preferred approach remains unknown and many recanalizations are futile with no clinical benefit. We sought to determine reasons for futility and weigh the existing reports to find whether endovascular mechanical interventions provide superior outcomes over pharmacological thrombolysis alone. Methods: After analyzing systematically the reports of outcomes produced by variable basilar artery occlusion recanalization protocols, information was retrieved and reconciled from 15 reports published from year 2005 comprising 803 patients in 17 cohorts. In the largest single-center cohort (162, Helsinki), predictors of futile recanalization (three-month modified Rankin Scale score 4 to 6) were determined. Results: Good outcome was reported by mechanical approaches either alone or on demand more frequently than by pharmacological, intravenous or intraarterial thrombolysis protocols (35.5% versus 24.4%, p< 0.001), accompanied by higher recanalization rates (84.1% versus 70.9%, p< 0.001). Along with superior recanalization rate at 91%, good outcome was reached by primary thrombectomy in 36% at the cost of substantial futile recanalization rate at 60%, which was lower when using modern stentrievers only (52.8%). In the Helsinki cohort, the single most significant predictor was extensive baseline ischemia, increasing the odds of futility 20-fold (95%CI 4.39–92.29, p< 0.001). Other attributes of futility were ventilation support and history of atrial fibrillation or previous stroke. Conclusions: Endovascular mechanical approaches have been reported to provide superior outcomes over pharmacological thrombolysis in basilar artery occlusion. Stricter patient selection, most notably to exclude victims of already extended ischemia, would assist in translating excellent recanalization rates into improved clinical outcomes and more acceptable futility rates.