Abstract:The surgical experience with 865 intracranial aneurysms is presented. Aneurysms arose from internal carotid artery 358 (41%), anterior cerebral artery 215 (25%), middle cerebral artery 192 (22%), vertebrobasilar circulation 100 (12%); 109 (13%) were giant aneurysms. Complex cerebral artery aneurysms are defined as aneurysms equal to or larger than 20 mm. There were 151 complex aneurysms, measuring 20 to 84 mm in diameter, in patients 16 to 72 years old. Fifty patients had subarachnoid hemorrhage, all had chronic headaches, 30 had focal neurologic findings secondary to mass effect. Ninety-eight patients underwent direct clipping, 16 had the aneurysm trapped and an intracranial anastomosis performed in 11, and 26 others had an extracranial-intracranial anastomosis in addition to trapping. Five patients had a proximal occlusion with no additional surgery, and five had endovascular treatment. Temporary clamp times: 7 to 155 minutes. Forty-seven patients did not have temporary clipping. Immediate neurologic worsening was noted in 53 patients, of whom 40 recovered before discharge, and 13 remained permanent. Of 15 deaths, five subarachnoid hemorrhage (grade 4 and 5) in whom vasospasm developed immediately after operation. Long-term recovery of the survivors (12-80 months) was excellent; 104 patients were normal, 5 patients had a mild deficit but returned to full function, and 14 had a severe deficit. Two more patients died of unrelated causes. Immediate postoperative angiography revealed complete obliteration or exclusion of the aneurysm in every patient. All extracranial-intracranial anastomoses were patent, as were all intracranial reconstructions. Collateral flow was observed in the territories of the distal arteries, which were trapped and not bypassed. Five patients who died had severe arterial vasospasm distal to the aneurysm location. All surviving patients returned to independent living, although only 30 were able to return to work. No additional deaths in the long-term survivors were related to their aneurysms or surgery. Complex cerebral artery aneurysm may be handled successfully without resorting to extraordinary measures, such as cardiopulmonary arrest.