Posterior Circulation Ischemia in the Endovascular Era

Abstract

Background and ObjectivesTo perform literature review of clinical, radiographic, and anatomical features of posterior circulation ischemia (PCI) and systematic review of the literature on the management of basilar artery occlusion (BAO) and associated outcomes.MethodsReview of literature was conducted to identify publications describing the risk factors, etiology, clinical presentation, and imaging for PCI. A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement. PubMed and Ovid MEDLINE were searched from 2009 to 2020 for articles relating to management of BAO. A synthesis was compiled summarizing current evidence on management of BAO.ResultsPCI accounts for 15%–20% of strokes. Risk factors are similar to anterior circulation strokes. Dizziness (47%), unilateral limb weakness (41%), and dysarthria (31%) are the most common presenting symptoms. A noncontrast head CT will identify PCI in 21% of cases; diffusion-weighted MRI or CT perfusion increase sensitivity to 85%. Recent trials have shown endovascular therapy can achieve >80% recanalization of BAO. In select patients, 30%–60% who receive endovascular treatment can achieve favorable outcome vs without. A total of 13% achieve good outcome and there is an 86% mortality rate.DiscussionPCI can present with waxing and waning symptoms or clinical findings that overlap with stroke mimics and anterior circulation ischemia, making diagnosis more heavily dependent on imaging. Recanalization is an important predictor of improved functional outcome and survival. In this endovascular era, trials of BAO are fraught with deterrents to enrollment. Despite limitations, endovascular treatment has shown improved outcome in select patients.

Outcomes of Endovascular Therapy in Young Patients with Acute Basilar Artery Occlusion: A Substudy of BASILAR Registry Study

“…Our findings also reveal associations between admission NIHSS, pc-ASPECTS, and recanalization and favorable outcomes at 90 days, which is further supported by previous studies [ 30 , 31 ]. Interestingly, we found sex as an independent predictor of mortality within 90 days for young patients.…”

Leaving the day behind: endovascular therapy beyond 24 h in acute stroke of the anterior and posterior circulation

“…BA occlusion was particularly frequent in our population treated beyond 24 h. Such occlusions based on pre-existing stenosis can be clinically challenging, as patients often present with unspecific dizziness or vertigo or gait imbalance and might initially be only mildly affected. 25 Therefore, physicians might refrain from direct vessel imaging, or, if BA occlusion is detected, consider the risk of treatment greater than the benefit. In our patients with posterior circulation stroke treated after more than 24 h (41.7%), despite good to excellent reperfusions achieved in more than 80%, only 16.7% of the patients reached favorable outcome, and mortality was high (41.7%).…”

The Neurointerventional Revolution

“…Symptoms in the posterior circulation may be atypical relative to the symptoms manifested by anterior circulation dysfunction. Novakovic-White et al 27 probe the manifestations, prognosis, and management of this less common but potentially more fatal stroke subgroup.…”