Microsurgical and endovascular management of pericallosal aneurysms

Pericallosal, or A2 bifurcation, aneurysms are an infrequently encountered cause of subarachnoid hemorrhage (SAH). While the International Subarachnoid Aneurysm Trial showed improved outcomes for patients with any ruptured anterior circulation aneurysm treated with embolization, there was also a higher recurrence rate for embolized aneurysms. Notably, there were relatively few pericallosal aneurysms.

Specific analysis of pericallosal aneurysms may help guide therapeutic decisions.

Retrospective analysis of patients who presented with proven saccular pericallosal aneurysms was performed at two institutions from 1999 to 2009. Patients were stratified according to presentation Hunt and Hess grades and modified Fisher scores, treatment modality and outcomes as well as development of vasospasm, hydrocephalus and required treatment.

Eighty-eight patients with pericallosal aneurysms were identified. Sixty-two presented with SAH and 26 in elective fashion, 2 of whom had a prior history of SAH. Fifty-four patients underwent microsurgical repair and 32 endovascular repair. Patients presenting with SAH due to pericallosal aneurysm treated with an endovascular approach were more likely to have a good modified Rankin scale (mRS) (mRS 0-2 vs 3-6) (p=0.028), to make a complete recovery (mRS=0) (p=0.017) and were less likely to die (mRS=6) (p=0.026). Patients with electively treated pericallosal aneurysms did not have statistically significant differences in outcome between surgical and endovascular cohorts. Differences in secondary endpoints did not reach significance.

Patients with ruptured pericallosal aneurysms fare better with endovascular therapy, with better chance of complete recovery. Surgical and endovascular treatments of unruptured pericallosal aneurysms have similar results and outcome.