Surgical management of anterior cerebral artery aneurysms of the proximal (A1) segment.

Objective: To report a series of 20 consecutive patients with aneurysms of the proximal segment (A1) of the anterior cerebral artery (ACA.

Methods: The medical records of patients who had undergone surgery for intracranial aneurysms at two institutions between January 1, 1989, and February 1, 2009, were reviewed. Mean patient age was 52.15 years (range 39-69 years). All 20 patients underwent direct surgery, with clipping or trapping, via standard pterional craniotomy.

Results: The incidence of A1 segment aneurysm was 0.59%. There were 16 women and 4 men, showing a strong predominance of this lesion in women. Mean aneurysm size was 6.95 mm (range 3-10 mm). Four patients (20%) had multiple aneurysms, and three patients (15%) had associated vascular anomalies. Among patients whose aneurysms originated from perforating arteries, dissection sacrificed the perforating arteries in two patients, and the perforating arteries occluded postoperatively in three patients. In the patients whose aneurysms did not originate from perforating arteries, no perforating arteries were sacrificed during dissection, and perforating arteries became occluded in two patients postoperatively. There was no statistically significant difference between the two groups of patients regarding the incidence of injury or occlusion. Clinical outcomes were as follows: good recovery in 15 (75%) patients, moderate disability in 2 (10%) patients, severe disability in 2 (10%) patients, and death in 1 (5%) patient.

Conclusions: The important consideration in surgery for intracranial aneurysms is preservation of the perforating arteries, through cautious dissection around the neck or dome and avoidance of direct clip compression, even after releasing the retracted frontal lobe.