Posterior Circulation Aneurysmal Subarachnoid Hemorrhage: A Comparison Between Saccular and Dissecting Aneurysms

Abstract

Background

There is a lack of comparative studies between posterior circulation saccular aneurysms (SA) and dissecting aneurysms (DA). This study aims to comprehensively compare the clinical characteristics, treatment strategies, and outcomes of SA and DA.

Methods

We included all consecutive patients with posterior circulation aneurysmal subarachnoid hemorrhage (aSAH) who underwent surgical treatment between January 2017 and December 2020 from the Chinese Multicenter Cerebral Aneurysm Database (CMAD). Baseline data were retrospectively collected, and survival status and 2-year mRS scores were prospectively assessed. Functional outcomes were categorized as favorable (mRS 0–2) and unfavorable (mRS 3–6). Logistic regression models were used to explore the association between aneurysm morphology and outcomes.

Results

Note that 406 patients with posterior circulation aSAH who underwent surgical treatment were included, comprising 314 (77.3%) with SA and 92 (22.7%) with DA. In unadjusted analyses, DA was associated with a lower rate of unfavorable outcomes at 2 years (17.1% vs. 34.8%, p = 0.003) but a higher rate of parent vessel sacrifice (22.8% vs. 8.0%, p < 0.001), while ischemic complications were comparable between groups. After further adjustment for covariates, DA showed a trend toward a lower risk of unfavorable outcomes in Model 3 (OR = 0.490, 95% CI 0.237–1.013, p = 0.054). In addition, the association between DA and a higher risk of parent vessel sacrifice remained consistent across all models (Model 1: OR = 3.419, 95% CI 1.811–6.456, p < 0.001; Model 2: OR = 2.737, 95% CI 1.415–5.293, p = 0.003; Model 3: OR = 2.899, 95% CI 1.463–5.747, p = 0.002).

Conclusion

DA may be associated with a trend toward better long-term functional outcomes compared with SA. Although parent vessel sacrifice was more frequently required, it was not associated with an increased risk of ischemic complications.