Direct microsurgical approach to aneurysms of the internal carotid bifurcation.

In this report, a series of 21 aneurysms of the internal carotid bifurcation, all treated with a direct microsurgical approach, is discussed. A classification of these aneurysms, according to angiographic and anatomical considerations, is proposed. The surgical treatment of aneurysms of the internal carotid bifurcation is discussed, emphasizing the importance of avoiding damage to perforating vessels. One of the patients presented in this report died from postoperative vascular spasm and three had transient disturbances in the postoperative course. All surviving patients recovered completely.