Thrombectomy for Basilar Artery Occlusion with Mild Symptoms

Abstract

To evaluate outcomes of thrombectomy in patients with a basilar artery occlusion (BAO) and mild symptoms, defined by an initial National Institutes of Health Stroke Scale (NIHSS) score ≤6. We performed a retrospective analysis of a multicenter prospective cohort of consecutive patients with acute ischemic stroke with BAO who underwent thrombectomy. We compared baseline and procedural characteristics, as well as outcomes between patients with BAO with an NIHSS score ≤6 and >6. Multivariate analyses were performed to determine baseline and procedural predictors of good outcome (modified Rankin Scale score 0-2) among patients with an NIHSS score ≤6. A total of 269 patients were included: 50 (19%) had an initial NIHSS score ≤6 and 219 (81%) had an NIHSS score >6. Patients with mild strokes (NIHSS score ≤6) had better outcomes (68% of modified Rankin Scale score 0-2 vs. 27% for NIHSS score >6; P < 0.0001), lower mortality (14% vs. 48; P < 0.0001) and fewer parenchymal hematomas at day 1 (0% vs. 10%; P= 0.016). A multivariate analysis identified the following predictors for good outcome among patients with BAO with an NIHSS score ≤6: younger age, fewer passes, a cardioembolic cause, and the absence of need for angioplasty/stenting. Thrombectomy seems to be safer and more effective for mild BAO strokes with NIHSS score ≤6 than for more severe patients. Even although thrombectomy showed high rates of recanalization, a substantial proportion (32%) nevertheless had a poor long-term clinical outcome. The number of passes, patient's age, and stroke cause seem to be predictors of clinical outcome.