Surgical alternatives in the treatment of cavernous sinus aneurysms.

Direct surgery on aneurysms in the cavernous sinus is a formidable technical procedure. The intimate relationship of the intracavernous carotid artery to the venous structures and to the cranial nerves make surgical access difficult at best. Thirty-two of 356 aneurysm patients presented with symptomatic aneurysms originating from the intracavernous internal carotid artery. Twenty-one patients had aneurysms contained entirely within the cavernous sinus, and in 11 others the aneurysms arose within the cavernous sinus and extended into the subarachnoid space. Of the purely intracavernous aneurysms there were five small aneurysms (less than 25 mm) and 16 giant (greater than or equal to 25 mm) aneurysms. Fifteen patients with purely intracavernous lesions had a superior orbital fissure syndrome, and six had a variety of other symptoms. Of 11 patients with subarachnoid extension, five had a subarachnoid hemorrhage (Grade I or II), five had ipsilateral visual loss, and one had periorbital pain. The aneurysms were treated as follows: Group 1 received progressive ligation of the internal carotid artery in the neck with a Selverstone clamp and a surface superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis (purely intracavernous in nine, and with subarachnoid extension in one); Group 2 underwent trapping of the internal carotid artery and a deep STA-MCA anastomosis (purely intracavernous in seven); and Group 3 had direct clipping of the aneurysm (purely intracavernous in five, and with subarachnoid extension in 10). The cavernous sinus was entered directly through its roof by a pterional craniotomy with radical removal of the optic canal, lesser sphenoid wing, and lateral and superior orbital walls. Proximal control of the internal carotid artery was obtained through a cervical incision. Two patients in Group 1 developed transient neurological deficits, which resolved. Two patients in Group 2 developed a cerebral infarction, one of whom died; in both of these patients, the anastomosis was completed after the internal carotid artery occlusion. Two patients in Group 3 progressed from marked visual loss to blindness of the same side, and one developed an intraventricular hemorrhage during induction of anesthesia and died without surgery. It is proposed that a direct approach to symptomatic aneurysms in the cavernous sinus is the best initial alternative. When this approach is not feasible, a trapping procedure preceded by a high-flow extracranial-intracranial anastomosis may be considered. Although the authors have been able to clip aneurysms of various sizes, this has not been possible in all patients. Further work is needed in this area.