Microsurgical and angiographic analysis of anterior communicating artery aneurysms with associated anomalies.

A direct operation was performed on 110 patients with an aneurysm of the anterior communicating artery (ACoA). During the surgery, in 52% of the cases, the neck of the aneurysm was found at the junction of the A-1 segment and ACoA and they presented with a hypoplastic contralateral A-1 segment. Associated ACoA anomalies were seen in 13 (12%) of the 110 cases. The most common anomaly was duplication of the ACoA, found in 11 cases (10%). In 2 other cases triplicate ACoA was found. Preoperative bilateral carotid angiograms were reviewed and duplication of the ACoA associated with the aneurysms able to be pointed out on angiograms in 4 cases, retrospectively. The anatomical and radiological aspects of aneurysms with associated anomalies are also discussed.