DOI: 10.5061/dryad.wpzgmsbmm
title: Posterior Circulation Ischemia in the Endovascular Era

description: Objective To elucidate the topic a literature review of clinical,
 radiographic and anatomical features of posterior circulation ischemia
 (PCI) was summarized, and systematic review of the literature on the
 management of basilar artery occlusion (BAO) and associated outcomes was
 performed. Methods Review 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
 Preferred Reporting Items for Systematic Reviews and Meta-Analysis
 statement.1 Pubmed and Ovid MEDLINE were searched from 2009-2020 for
 papers relating to management of BAO.  A synthesis was compiled
 summarizing current evidence on management of BAO. Results PCI account for
 15-20% of strokes.  Risk factors are similar to anterior
 circulation strokes.  Dizziness (47%), unilateral limb weakness
 (41%), and dysarthria (31%) are most common presenting symptoms. 
 A non-contrast 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 &gt;80%
 recanalization of BAO.  In select patients, 30-60% that receive
 endovascular treatment can achieve favorable outcome versus without 13%
 achieve good outcome and 86% mortality rate. Conclusion PCI 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.
description: To elucidate best
 management of acute BAO in an endovascular era of newer generation MT
 devices, a systematic review was performed in accordance with Preferred Reporting
 Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines (Figure
 6).<sup>1</sup>  Pubmed and Ovid MEDLINE were searched from January 2009 to October 2020 for papers relating to management of BAO using search criteria BA, treatment and stroke. Previous meta analyses, RCT, systematic reviews and case series with more than 5 cases were included. Papers about pediatric population, isolated VA occlusion, VA stenosis treated with angioplasty and stenting for nonacute strokes, expert opinions and study protocols (except for one RCT near completion) were not included. A synthesis was compiled summarizing the current evidence regarding management of acute BAO. After removal of duplications, the initial search revealed 440 articles, of which 58 studies were related to acute BAO management.  Thirty-seven publications<sup>58-94</sup> and 1 RCT which reported results at an international meeting May 13, 2020 (publication pending)<sup>95</sup> met the final inclusion criteria.  Seven systematic reviews or meta-analyses and 2 reviews of the literature on the subject were included to identify articles that may have been missed during the literature review.  Two studies were RCTs comparing IVT vs IVT plus endovascular treatment (EVT).  Twenty-one, either prospective or retrospective, observational studies describing the recanalization rates and outcomes of BAO treated with EVT were identified.  Additionally, 5 registries on PCI and 1 study protocol of an ongoing prospective RCT near completion were included.  The papers were evaluated and the data was summarized in the article.