Risk Factors for Unfavorable Functional Outcome after Endovascular Treatment of Cerebral Vasospasm following Aneurysmal Subarachnoid Hemorrhage

BACKGROUND AND PURPOSE: Cerebral vasospasm remains a strong predictor of poor outcomes after aneurysmal subarachnoid hemorrhage (aSAH). Endovascular treatment of vasospasm can be considered when conservative treatment options are exhausted, but its superiority over standard treatment remains a subject of critical debate. This study focuses on patients with clinically relevant vasospasm after aSAH who underwent endovascular vasospasm treatment and aims to analyze patients’ individual risk factors, intensity, and extent of cerebral vasospasm associated with poor functional outcomes after aSAH.

MATERIALS AND METHODS: We conducted a retrospective cohort study of consecutive patients with aSAH admitted at a tertiary stroke center between January 2016 and December 2022. Patients with medically refractory cerebral vasospasm necessitating at least 1 endovascular intervention were analyzed. Primary end point was defined as functional outcome defined as modified Rankin Scale (mRS) scores after 6 months. Secondary end point was the occurrence of cerebral infarctions following cerebral vasospasm.

RESULTS: Overall, 138 patients received endovascular treatment due to cerebral vasospasm, including 322 treatments, with 78 patients receiving more than 1 endovascular treatment. In 65.2% (90) of patients, cerebral vasospasm developed in both hemispheres; in 16.7% (23), cerebral vasospasm occurred involving the posterior circulation; and in 10.1% (14), percutaneous transluminal angioplasty was performed. Multivariable logistic regression analysis showed an association of higher age (adjusted odds ratio [aOR], 1.05, 95% CI: 1.0–1.1), higher Hunt and Hess grades (aOR, 2.12, 95% CI: 1.38–3.24), the occurrence of rebleeding (aOR, 4.97, 95% CI: 1.0–24.65), and bihemispheric vasospasm (aOR, 4.05, 95% CI: 1.4–11.72) with unfavorable outcome (mRS 3–6). Further analysis showed that higher age (aOR, 1.07, 95% CI: 1.03–1.13) was associated with an increased risk of developing vasospasm-associated infarctions.

CONCLUSIONS: Our results indicate an association between bihemispheric cerebral vasospasm and poor functional outcomes after aSAH. This finding supports a more aggressive treatment strategy in patients developing bihemispheric vasospasm to prevent unfavorable disease courses.