Far lateral suboccipital approach for the treatment of proximal posteroinferior cerebellar artery aneurysms: surgical results and long-term outcome.

OBJECTIVE: Proximal posteroinferior cerebellar artery (PICA) aneurysms are challenging to treat surgically, with high reported perioperative complication rates. We describe the perioperative course and long-term clinical outcomes obtained via a far lateral suboccipital approach in 20 consecutive proximal PICA aneurysms.
METHODS: Data were collected prospectively on the first 20 proximal PICA aneurysms treated surgically by a single surgeon (ESC) between December 1997 and April 2003. All aneurysms were clipped via a far lateral approach. Patients with unruptured aneurysms were assessed at 3 and 12 months after surgery. For all subarachnoid hemorrhage patients, a battery of outcome tests was performed at 3- and 12-month intervals. Outcomes were then compared with those of a contemporaneously managed population of ruptured right-sided posterior communicating artery aneurysms.
RESULTS: The far lateral suboccipital approach achieved adequate exposure in all cases. There were no intraoperative complications or intraoperative aneurysm ruptures. All patients with unruptured aneurysms were fully functional at long-term follow-up. At 3 months of follow-up, 93% of the subarachnoid hemorrhage patients achieved a Glasgow Outcome Scale score of 1 to 2. At 12 months of follow-up, 92% achieved a Glasgow Outcome Scale score of 1 to 2. Compared with the patients with a ruptured right-sided posterior communicating artery aneurysm, no difference could be found in quality of life or activities of daily living at either time point.
CONCLUSION: The favorable outcomes and low postoperative morbidity in this subset of patients argues that clipping via this approach be considered a first-line therapeutic option. When performed in this manner, PICA aneurysm surgery seems to have no greater morbidity than right-sided posterior communicating artery aneurysm surgery.