Treatment and Outcomes Among 102 Posterior Inferior Cerebellar Artery Aneurysms: A Comparison of Endovascular and Microsurgical Clip Ligation

BACKGROUND: The vicinity of brainstem and cranial nerves as well as the limited operative working space make clip ligation of posterior inferior cerebellar artery (PICA) aneurysms challenging. The small caliber of the PICA and the broad neck often associated with these aneurysms also create challenges in preserving this artery during treatment. Few data exist to compare the 2 treatment approaches for aneurysms in this location. OBJECT: To assess treatment outcomes for PICA aneurysms based on mode of management and anatomical location. METHODS: A prospectively maintained database was queried for PICA aneurysms treated from 2000 through 2012. Patients were categorized on the basis of their aneurysm's anatomical location, presentation status, treatment modality, and subsequent complications. Descriptive, univariate, and multivariate statistical analyses were performed. RESULTS: A total of 113 PICA aneurysms were identified; 11 did not undergo treatment. Of the remaining 102 aneurysms, 77% were ruptured and 64% were treated microsurgically. In the ruptured group, patients with more proximally located aneurysms such as vertebral and proximal PICA aneurysms were more likely to experience hydrocephalus and cranial nerve deficits after treatment. Endovascular therapy was less likely to cause postoperative deficit or lead to a need for percutaneous endoscopic gastrostomy. Most importantly, discharge, 6-month, and 1-year outcomes were predicted based on presenting Hunt and Hess score and patient's age, not aneurysm location or management mode. CONCLUSIONS: PICA aneurysms are challenging and require a multimodality treatment paradigm. Although microsurgery is associated with more short-term postoperative complications, presenting grade and patient's age remain the primary predictors of long-term outcome.