Posterior circulation stroke from diagnosis to management, including recent data on thrombectomy for basilar artery occlusion from the BAOCHE and ATTENTION trials

Abstract

Posterior circulation stroke accounts for one-fifth of all strokes, but despite this, it has been a neglected area. It can present considerable challenges in diagnosis, and there are fewer studies examining optimal treatment compared with anterior circulation stroke. This month's issue of IJS attempts to address this balance. We have a particular focus on posterior circulation stroke with coverage of areas ranging from diagnosis, through acute treatment and thrombectomy, to secondary prevention. This initiative is particularly opportune with the recent announcement of two positive studies of thrombectomy for basilar artery occlusion (BAO).Diagnosis of posterior circulation stroke can be challenging, in part because of substantial overlap in symptoms and signs with ischemia in the anterior circulation, but some clinical signs are highly specific to posterior circulation strokes because of the unique functions and vascular supply of the brainstem. A comprehensive review from Salerno and colleagues describes the clinical and corresponding anatomical features of PC stroke, and highlights specific syndromes. 1 It also covers optimal imaging approaches. It makes for a very useful clinical update.Management of posterior circulation stroke, particularly acute reperfusion therapy and neurointervention procedures for secondary prevention, has received much less attention than similar interventions for the anterior circulation. For example, whether thrombectomy is as effective for BAO as it is for anterior circulation stroke is debated, particularly after the negative BASICS trial. 2 Our second review in this issue provides the latest data on management of posterior circulation stroke, both acute and secondary prevention. 3 It highlights the results from two recent trials of thrombectomy presented in May at the European Stroke Congress 2022, which both showed that thrombectomy was highly effective for BAO. 4 ATTENTION (EndovAscular TreaTmENT for acute basilar artery occlusION), the protocol paper of which is also published in this issue, 5 recruited patients within 0-12 h from the estimated time of stroke onset in China. A total of 340 patients were randomly assigned to thrombectomy or best medical management in a 2:1 ratio. There was a highly significant improvement in the primary endpoint of modified Rankin score 0-3 at 90 days which was achieved in 104/226 (46%) of the endo-

Imaging Advances in Stroke: Use of Advanced Neurovascular Imaging or Disruptive Innovation With Artificial Intelligence?

“…For basilar artery occlusion, recent positive randomized trials and looming regulatory decisions provocatively ask whether any type of advanced neurovascular imaging is necessary. 7 The collateral routes, associated perfusion maps, lesion size, association with underlying etiology of occlusion, and timecourse of lesion evolution may not be relevant or critical in medical decision-making for evaluation and treatment of basilar artery occlusion.…”

Efficacy and safety of mechanical thrombectomy in the posterior cerebral circulation—a single center study

“…Although there is limited data available on the efficacy and safety of MT in the posterior vasculature, recent studies have demonstrated the effectiveness of this procedure compared to the best non-invasive treatment 2 , 3 . Acute ischemic strokes in the posterior cerebral vessels are estimated to account for 13.5–20% of all strokes 4 – 6 .…”

Real‐World Outcomes of Endovascular Thrombectomy for Basilar Artery Occlusion: Results of the BArONIS Study

“…3 Although a preponderance of evidence had previously demonstrated equipoise between endovascular thrombectomy (EVT) and medical therapy alone for the treatment of acute BAO, recent randomized clinical trial data have, for the first time, demonstrated a clinical benefit to EVT in the posterior circulation. 4 This study [termed the BAO National Inpatient Sample (BArONIS) study] draws on real-world populationlevel data from the United States to examine the association between EVT and clinical outcomes in acute BAO patients.…”

“…Basilar artery occlusions (BAO), which account for approximately 10% of large vessel strokes, 2 confer especially poor outcomes, as severe deficits persist in 80% or more of patients following treatment and as many as 40% may progress to mortality 3 . Although a preponderance of evidence had previously demonstrated equipoise between endovascular thrombectomy (EVT) and medical therapy alone for the treatment of acute BAO, recent randomized clinical trial data have, for the first time, demonstrated a clinical benefit to EVT in the posterior circulation 4 . This study [termed the BAO National Inpatient Sample (BArONIS) study] draws on real‐world population‐level data from the United States to examine the association between EVT and clinical outcomes in acute BAO patients.…”