MATERIAL and METHODS: Data relating to clinical presentation, radiological findings, operative approaches and outcomes were analyzed in 27 consecutive patients surgically treated for PICA aneurysms in a single hospital between January 1991 and December 2010.

RESULTS: Headache was the most common presentation (100%) followed by gait ataxia (14.8%) and lower cranial nerve dysfunction (7.4%). SAH was seen in 20 patients, intraventricular hemorrhage in 22 patients, and 3 had evidence of intracerebellar hematoma. Eighteen aneurysms were located proximally and 9 were located distally. The 25 saccular and 2 fusi-saccular aneurysms were secured by direct clipping (24 cases) or aneurysmorrhaphy (3 cases) using a far-lateral suboccipital (without condylar resection) or midline/ paramedian suboccipital approach. Overall outcome at the time of hospital discharge was excellent or good in 88.9% of the patients.

CONCLUSION: PICA aneurysms, by virtue of their rarity and strategic location pose a unique technical challenge. Depending on the PICA segment affected, variations in the surgical corridor and clipping strategy were major contributors to good outcomes. Keywords : Posterior inferior cerebellar artery, Intracranial aneurysm, Subarachnoid hemorrhage, Far lateral suboccipital approach, Outcome