Exact Basilar Artery Occlusion Location Indicates Stroke Etiology and Recanalization Success in Patients Eligible for Endovascular Stroke Treatment

Abstract

Introduction Endovascular stroke treatment (EST) is commonly performed for acute basilar artery occlusion (BAO). We aimed to identify the role of the exact location of BAO in patients receiving EST regarding the stroke etiology, recanalization success and prediction of favorable clinical outcome. Methods Retrospective analysis of 191 consecutive patients treated for BAO with EST from 01/2013 until 06/2021 in a tertiary stroke center. Groups were defined according to exact location of BAO in I: proximal third, II: middle third, III: distal third and IV: tip of the basilar artery. Univariate and multivariate analyses were performed for BAO location comparing stroke etiology, recanalization result and favorable clinical outcome according to mRS 0–3 90 days after stroke onset. Results Occlusion sides types I–IV were evenly distributed (37, 36, 60 and 58 patients). Types I and II were more often associated with large artery atherosclerosis (50 vs. 10 patients, p < 0.001). Distal/tip occlusion (types III/IV) occurred mostly in cardiac embolism or embolic stroke of unknown source (89 vs. 12 in types I/II, p < 0.001). Occlusion site correlated with the underlying stroke etiology (AUC [Area under the curve] 0.89, p < 0.0001, OR [odds ratio] for embolism in type IV: 245). Recanalization rates were higher in patients with distal occlusions (type III/IV OR 3.76, CI [95% confidence interval] 1.51–9.53, p = 0.0076). The BAO site is not predicting favorable clinical outcome. Conclusion The exact basilar artery occlusion site in patients eligible for endovascular stroke treatment reflects the stroke etiology and is associated with differing recanalization success but does not predict favorable clinical outcome.

Impact of the basilar artery occlusion location on the recanalization rate and clinical outcome with endovascular therapy

“…proximal and middle BAO (27% and 23%) even though the difference was not statistically signi cant (P = 0.093). 7 However, it is important to note that Mutke et al employed a distinct classi cation method for the BAO location to that used in our study and did not exclude patients with mild stroke from their analysis who are less likely to bene t from EVT. 5,7 The differences in methodology may explain why in the study of Mutke et al, the BAO location did not have a signi cant impact on the clinical outcome.…”

“…These ndings were in line with those published in previous studies. 7,[15][16][17][18] In such cases, a longer intraoperative procedure may increase the risk of damaging the vascular endothelium and eventually lead to platelet activation, reformation of the thrombus, and, ultimately, occlusion. 19 In our study, 50.9% and 62.7% of cases in the proximal and middle occlusion groups, respectively, required rescue therapy.…”

“…6 Previous studies have demonstrated that the location of the BAO was associated with the underlying stroke mechanism. 7,8 However, the effect of the speci c BAO location on the recanalization rate and clinical outcome after EVT is not fully understood. Various anatomical and pathologic factors can contribute to this variation.…”

Endovascular Treatment for Acute Basilar Artery Occlusion: A Fragility Index Meta-Analysis

“…The site of occlusion is also linked to the underlying etiology, since embolic stroke will more frequently involve the distal basilar artery, whereas proximal BAO is usually linked to atherosclerotic lesions of the vertebrobasilar junction. These differences also have treatment implications, since it has been shown that recanalization rates are higher in patients with distal BAO occlusions [ 28 ]. Furthermore, among all stroke subtypes, adjunctive pharmacotherapy, such as antiplatelet agents and anticoagulants, either in the acute–subacute phase or as secondary stroke prevention measures, may inherently influence the efficacy and safety following acute reperfusion therapies [ 29 , 30 ].…”

Endovascular treatment of acute basilar artery occlusion: A systematic review and meta‐analysis of first‐line stent retriever versus direct aspiration

“…Although thromboembolism is a more common cause of ischemic stroke with large and medium size vessel occlusion in the anterior circulation, the underlying etiology of basilar artery occlusion is often associated with cardioembolism, large artery atherosclerosis, and other mechanisms such as dissection and vasculopathy (Buchman & Merkler, 2019 ). Importantly, basilar artery occlusion stemming from atherosclerotic disease tends to be linked with unfavorable clinical outcomes (Lee et al., 2017 ; Mutke et al., 2023 ). During a basilar artery occlusion, atherosclerotic occlusions are commonly observed in proximal locations, whereas thromboembolic occlusions tend to occur more frequently in distal locations (Mutke et al., 2023 ).…”