Posterior Inferior Cerebellar Artery/Vertebral Artery Subarachnoid Hemorrhage: A Comparison of Saccular vs Dissecting Aneurysms.

BACKGROUND: Two distinct categories of aneurysms are described in relation to the posterior inferior cerebellar artery (PICA) and vertebral artery (VA): saccular (SA) and dissecting (DA) types. This distinction is often unrecognized because abnormalities here are uncommon and most studies are small.

OBJECTIVE: To determine if there are any differences in the clinical presentation, in-hospital course, or outcomes in patients with DA vs SA of the PICA or VA.

METHODS: Thirty-eight patients with a VA or PICA aneurysm were identified from a departmental subarachnoid hemorrhage database and categorized into DA or SA types. Prospectively collected demographic and outcome data (length of stay, discharge Glasgow Outcome Score) were supplemented by abstracting records for procedural data (extraventricular drain [EVD], ventriculoperitoneal [VP] shunt, tracheostomy, and nasogastric feeding). Univariate, binary logistic regression, and Cox regression analysis was used to compare patients with SA vs DA.

RESULTS: Three aneurysms related to arteriovenous malformation were excluded. Five patients were conservatively managed. Of the 30 treated cases, more patients with a DA presented in poor grade (6/13 vs 2/17 SA; P = .035). More DA patients required an EVD (85% vs 29%; P = .003), VP shunt (54% vs 6%; P = .003), tracheostomy (46% vs 6%; P < .01), and nasogastric feeding (85% vs 35%; P = .007). The median length of stay (41 vs 17 d, P < .001) was longer, and the age and injury severity adjusted odds of discharge home were significantly lower in the DA group (P = .008). Thirty-day mortality was not significantly different (23% of DA vs 24% of SA; P = .2).

CONCLUSION: The presentation, clinical course, and outcomes differ in patients with DA vs SA of the PICA and VA.