Outcomes in Endovascular Therapy for Basilar Artery Occlusion: Intracranial Atherosclerotic Disease vs. Embolism

Abstract

Acute ischemic stroke due to basilar artery occlusion (BAO) carries a very poor prognosis. Functional outcomes in BAO patients undergoing endovascular therapy (EVT) may differ according to the specific pathological mechanisms. We aimed to explore the impact of the underlying pathological mechanisms on prognosis at 90-days and long-term follow-up in BAO patients treated with EVT. We analyzed consecutive BAO patients undergoing EVT from December 2012 to December 2018 at a single center (Xuanwu Hospital). Patients were classified into either an intracranial atherosclerotic disease (ICAD) group or an embolic group according to the corresponding angiographic findings. The baseline characteristics and functional outcomes were compared between the two groups. Multivariable logistic regression analysis was performed. Among the 167 patients enrolled, 78 patients (46.7%) were in the ICAD group and 89 patients (53.3%) were assigned to the embolic group. Overall, 149 patients (89.2%) achieved successful reperfusion post-EVT. There were no significant differences in functional outcomes at 90-days and long-term follow-up between the two groups. Similarly, a Kaplan-Meier survival analysis showed similar long-term survival probabilities (P = 0.438). The pathological mechanism was not associated with functional independence (OR, 1.818; 95% CI, 0.694-4.761; P = 0.224), favorable outcome (OR, 1.476; 95% CI, 0.592-3.681; P = 0.403), or mortality (OR, 1.249; 95% CI, 0.483-3.226; P = 0.646). However, based on subgroup analysis, embolic BAO versus ICAD was significantly associated with better functional independence in those aged 60 years and younger (OR, 4.513; 95% CI, 1.138-17.902). In this study, no differences in either 90days or long-term functional outcomes between ICAD-related BAO and embolic BAO patients undergoing EVT were observed. However, in BAO patients aged ≤ 60 years, the pathological mechanism of embolism was associated with better functional independence.

Endovascular Thrombectomy for Acute Basilar Artery Occlusion: Latest Findings and Critical Thinking on Future Study Design

“…Intraprocedural use of glycoprotein IIb/IIIa inhibitor, percutaneous transluminal angioplasty, or stenting for underlying intracranial stenosis as rescue therapy was shown to improve the rate of functional outcome. With the use of rescue therapy, there was no significant difference in the rates of favorable outcome between in situ atherosclerotic thrombosis group and embolic group (26.9% vs. 33.7%, 37.5% vs. 41.5%, or 60% vs. 51%, respectively) [26,55,57].…”

“…Due to poor natural history, significant numbers of patients with acute BAO were treated with EVT empirically worldwide in the last 2 decades. Eighteen published retrospective studies were found to have sample size ≥ 100 and functional outcome data at 90 days [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. In these studies, most patients had median or mean National Institutes of Health Stroke Scale (NIHSS) scores 14-31.…”

“…Futile recanalization was defined as a technical success without meaningful improvement in functional outcome [18,25,26]. Compared with large vessel occlusion in the AC, BAO was associated with increased rate of futile recanalization [18,32].…”

“…Extensive baseline infarction or large pontine infarct was found to be associated with higher rate of futile recanalization and poor outcome at 90 days. [18,25,26,30,33] The BASICS trial showed higher basilar artery patency at 24 h post-enrollment in the EVT group than in medical group (84.5% vs. 56.3%) [37], suggesting a significant rate of futile recanalization.…”

“…Approximately 24-47% of patients with acute BAO were found to have underlying intracranial atherosclerotic disease and superimposed in situ thrombosis [19,26,29,[54][55][56][57]. Patients with underlying intracranial stenosis were found to have longer procedure time, lower recanalization rate, or higher rate of re-occlusion than those with embolic occlusion [19,26,54,55]. They were also found to have lower rate of favorable outcome than patients with embolic occlusion (37.9% vs. 62.1%, 20% vs. 53%, or 10.5% vs. 37.5, respectively) [19,54,56].…”