Surgical treatment of internal carotid siphon aneurysms

AbstractSurgical treatment of internal carotid artery aneurysms around the carotid siphon is discussed. The surgical approach to the aneurysms in this region, is as follows: 1. A fronto-temporal approach with the patient in a 45° semi-sitting position to decrease venous pressure. 2. A Dolenc approach cutting a part of the dura mater of the superior orbital fissure to facilitate removal of the anterior clinoid process and unroofing of the optic canal. 3. Opening the medial triangle followed by transection of the optic canal duraI sheath. Carotid siphon aneurysms can be divided into three groups anatomically; aneurysms of the ophthalmic segment (C2), those of the clinoid segment (C3), and those of the horizontal segment (C4). We present 29 cases of aneurysms arising from the C2 or C2/3 segment, 14 cases arising from the C3 or C3/4 segment, and 11 cases arising from the C4 segment. Anatomic localization of the aneurysms was established preoperatively by angiography and three-dimensional CT imaging. Small ane...