Response to Late-Window Endovascular Revascularization Is Associated With Collateral Status in Basilar Artery Occlusion

Abstract

Background and Purpose— The benefit of endovascular therapy in extended time windows has been demonstrated in patients with anterior circulation large vessel occlusion ischemic stroke and favorable imaging profile. We evaluated whether collaterals and thrombus burden influence the associations between revascularization, time-to-treatment, and outcome in endovascular therapy-treated patients with basilar artery occlusion. Methods— We retrospectively analyzed clinical and imaging data of consecutive endovascular therapy-treated patients with basilar artery occlusion included in the multicenter Basilar Artery Treatment and Management Collaboration. The BATMAN (Basilar Artery on Computed Tomography Angiography score, which evaluates thrombus burden and collaterals) and the PC-CS (Posterior Circulation Collateral score, which evaluates collaterals) were assessed on computed tomography angiography, blinded to clinical outcome. Good outcome was defined as modified Rankin Scale score of ≤3 within 3 months; revascularization (successful reperfusion) as modified Thrombolysis in Cerebral Infarction 2b–3 (or TIMI [Thrombolysis in Myocardial Infarction] 2–3 in the BASICS [Basilar Artery International Cooperation Study] registry). Results— We included 172 patients with basilar artery occlusion treated with endovascular therapy (124 with mechanical thrombectomy): mean (SD) age 65 (13) years, median National Institutes of Health Stroke Scale 22 (interquartile range 12–30), 64 (37%) treated >6 hours. Revascularization (achieved in 79% of patients) was associated with good outcome ( P =0.003). The use of new generation thrombectomy devices was associated with good outcome ( P =0.03). In patients who achieved revascularization, 29/46 (63%) of patients with a favorable BATMAN score and 26/51 (51%) with favorable PC-CS had good outcomes. In logistic regression analysis (adjusted for age, National Institutes of Health Stroke Scale, and time-to-treatment ≤6/>6 hours), revascularization was associated with good outcome in patients with favorable BATMAN score (odds ratio, 15.8; 95% CI, 1.4–175; P =0.02) or PC-CS (odds ratio, 9.4; 95% CI, 1.4–64; P =0.02). In patients who achieved revascularization, early (time-to-treatment ≤6 hours) but not late treatment was associated with improved outcome in patients with unfavorable BATMAN score (18/52 [35%]; odds ratio, 15; 95% CI, 1.9–124; P =0.01) or PC-CS (16/44 [36%]; odds ratio, 5.5; 95% CI, 1.4–21; P =0.01). Conclusions— Revascularization is associated with good outcome in patients with basilar artery occlusion with good collaterals and less extensive occlusion, even >6 hours after onset.

A Child with Paradoxical Cerebral Embolism in Whom Mechanical Thrombectomy Led to a Favorable Outcome

“…However, Lindsberg et al 6) reported that when posterior communicating artery-mediated blood flow from the anterior circulation system was sufficient, thrombosis of the BA did not frequently lead to embolism at the BA end due to blood flow, suggesting that posterior circulation system ischemia progression over time is slower than anterior circulation system ischemia progression. Furthermore, Alemseged et al 7) evaluated the thrombus size and collateral pathway using scoring systems, such as the Basilar Artery on Computed Tomography Angiography (BATMAN) score and Posterior Circulation Collateral Score (PC-CS), with respect to the visualization of the posterior communicating artery and posterior circulation blood vessels on contrast-enhanced cephalic CT at the time of onset, and suggested that the functional prognosis after mechanical thrombectomy is improved when the score is high even in patients with an interval of ≥6 hours from onset. In the present case, CT angiography (CTA) was not conducted and the scoring of MRA findings on arrival demonstrated sufficient collateral flow.…”

Postcontrast CT to Estimate Arteriosclerotic Stenosis at the Site of Occlusion before Emergency Endovascular Treatment for Vertebral–Basilar Artery Occlusion

“…1) Recently, several retrospective studies demonstrated the efficacy of mechanical thrombectomy for posterior circulation major artery occlusion. 7,15,16) Important factors for the favorable prognosis of patients with posterior circulation cerebral infarction included a favorable collateral pathway, narrow extent of occlusion, early reperfusion, and successful state of reperfusion. 7,[17][18][19][20] In patients with posterior circulation cerebral infarction, atherosclerosis was more frequent than in those with anterior circulation cerebral infarction.…”

“…4) The efficacy of mechanical thrombectomy for anterior circulation major artery occlusion was previously demonstrated, 5,6) and this procedure has become the standard treatment. Its efficacy for posterior circulation acute ischemic stroke has also been suggested, 7) but several studies reported that the addition of percutaneous transluminal angioplasty (PTA) was necessary when arteriosclerotic stenosis was detected at the site of occlusion during mechanical thrombectomy. [8][9][10] The presence of arteriosclerotic stenosis at the site of occlusion prevents early recanalization.…”

Extending boundaries for thrombectomy in stroke

“…We can clearly distinguish two groups of patients in anterior circulation stroke: slow progressors—those who are more likely to benefit from later intervention, and fast progressors—those with a malignant profile whose core will grow more quickly 5–7. This seems also to be true for posterior circulation stroke 8…”