Outcomes of Mechanical Angioplasty in Cerebral Vasospasm after Aneurysmal Subarachnoid Hemorrhage: Balloon versus Stentriever in a Propensity Score-Matched Analysis

Introduction: Cerebral vasospasm is the leading cause of morbidity and mortality after aneurysmal subarachnoid hemorrhage (aSAH). Mechanical angioplasty may improve vasospasm and reduce the risk of delayed cerebral ischemia; Optimal target and device selection remains controversial. We aimed to propose a minimum target of angioplasty for sustained efficacy and to compare the outcomes of balloon versus stentriever devices.

Methods: We identified consecutive patients who underwent mechanical angioplasty for aSAH vasospasm between 2018 and 2022. Primary outcome was successful angioplasty (residual narrowing < 50%) without complications. Secondary outcome included rates of refractory/recurrent vasospasm, retreatment, and sustained improvement at follow-up. The outcomes were compared between balloon and stentriever in a propensity score-matched cohort with balanced baseline and within subgroups. Associated features were identified through multivariable analysis.

Results: A total of 41 patients underwent 59 angioplasty procedures involving 149 vasospastic segments. Among the patients, 70.7% presented with Hunt-Hess grade III-V aSAH. Balloon angioplasty was employed in 127 segments, Comaneci in 16 segments and other stentrievers in 6 segments. 61.7% of angioplasties were performed in proximal anterior circulation (ICA, M1, A1), 20.1% in distal segments (A2 and M2) and 18.1% in posterior circulation. Successful angioplasty was achieved in 83.2% of vessels, while refractory/recurrent vasospasm was observed in 17.4%, resulting in a 10.1% retreatment rate. Notably, 68.8% of vessels that underwent successful angioplasty demonstrated sustained improvement at follow-up. Angioplasty targeting distal MCA (adjusted OR, 0.10) or BA-V4 (aOR, 0.10), and residual narrowing exceeding 50% (aOR, 0.03) were identified as unfavorable predictors for sustained improvement. Efficacy outcomes were similar between balloon and stentriever in a matched analysis.

Conclusion : Mechanical angioplasty, when achieving residual narrowing < 50%, demonstrated sustained improvement for vasospasm following aSAH. Novel stentriever devices may exhibit comparable efficacy to balloon angioplasty. Vigilant follow-up might be warranted after angioplasty for specific segments.