[Microsurgical treatment of large or giant aneurysms in anterior circle of Willis]

To improve the operative results in large or giant aneurysms of the anterior circle Willis.

Retrospective analysis was performed on 28 patients with large or giant aneurysms of the anterior circle Willis after operation. Three-D CT angiography was used to detect and delineate aneurysm preoperatively. Improved operative technique included cranial base approach, temporary artery occlusion, intra-aneurysm decompression, obliteration of aneurysm with multiple clips, stepwise coagulation clipping and resection of aneurysms.

Good results were noted in 24 patients (85.7%), fair in 2, and poor in 1. One patient died, but no patient with Hunt and Hess 0-III grade died.

Three-D CT angiography is useful in delineating the shape, size, neck of aneurysms, and their relation to near arteries and to cranial base structures. These are helpful to improve operative results of large or giant aneurysms of the anterior circle of Willis.