Microsurgical Clipping of an Unruptured Carotid Cave Aneurysm: 3-Dimensional Operative Video

Most aneurysms originating from the clinoidal segment of the internal carotid artery (ICA) are nowadays managed conservatively, treated endovascularly with coiling (with or without stenting) or flow diverters. However, microsurgical clip occlusion remains an alternative. This video demonstrates clip occlusion of an unruptured right carotid cave aneurysm measuring 7 mm in a 39-year-old woman. The patient opted for surgery because of concerns about prolonged antiplatelet use associated with endovascular therapy. After patient consent, a standard pterional craniotomy was performed followed by extradural anterior clinoidectomy. After dural opening and sylvian fissure split, a clinoidal flap was opened to enter the extradural space around the clinoidal segment. The dural ring was dissected circumferentially, freeing the medial wall of the ICA down to the sellar region and mobilizing the ICA out of its canal of the clinoidal segment. With the aneurysm neck in view, the aneurysm was clipped with a 45° angled fenestrated clip over the ICA. Indocyanine green angiography confirmed no further filling of the aneurysm and patency of the ICA. Complete aneurysm occlusion was confirmed with postoperative angiography, and the patient had no neurologic deficits (Video 1). This case demonstrates the importance of anterior clinoidectomy and thorough distal dural ring dissection for effective clipping of carotid cave aneurysms. Control of venous bleeding from the cavernous sinus with fibrin glue injection simplifies the dissection, which should minimize manipulation of the optic nerve. Knowledge of this anatomy and proficiency with these techniques is important in an era of declining open aneurysm cases.