Surgery of proximal anterior cerebral artery aneurysms

Aneurysms of the proximal segment of anterior cerebral artery (A1) are uncommon, but present a unique challenge to surgeons because of the risk of injury to the nearby perforating arteries. Surgical issues and treatment options, however, have not been detailed in the previous literature.

We report a consecutive series of 11 patients with A1 aneurysms focusing on the surgical considerations. The A1 aneurysms represented 3.4% of the 322 cerebral aneurysms treated in our hospital in the last 6 years. All patients presented with subarachnoid hemorrhage, and 8 patients (73%) had multiple aneurysms.

All aneurysms were secured by neck clipping via pterional craniotomy without any surgery-related morbidity. All of the aneurysms projected superiorly or posteriorly from the origin of the perforating artery of the A1 segment. The aneurysm dome was tightly adherent to the perforating arteries in 7 cases (64%) and the base extended broadly along the axis of the parent artery in 4 cases (36%).

Separating the perforating arteries from the neck or dome of the A1 aneurysm and preserving the vessel presents a substantial challenge to the surgeon, because the aneurysm is almost always behind the parent artery in the surgical field, making it difficult to achieve good access for this particular type of dissection. Consideration should be given to additional orbitotomy, wide opening of the Sylvian fissure, mobilization of the MCA and ICA, selection of aperture clip and intra-operative shortening of the clip blades.