Surgical strategies using cerebral revascularization in complex middle cerebral artery aneurysms.

OBJECTIVES: To describe surgical strategies using cerebral revascularization for complex middle cerebral artery aneurysms unsuitable to microsurgical clipping.

MATERIALS AND METHODS: In this study, the clinical features, case management, and results in 9 consecutive patients who underwent 10 cerebral revascularization procedures between January 1999 and April 2008 were retrospectively analyzed. The patient population consisted of 6 men and 3 women whose ages ranged from 15 to 71 years (mean, 42.4 years). The size of the aneurysms ranged from 12 to 35 mm (mean, 24.3 mm). Treated aneurysms were located in the M1 segment in 2 patients, the middle cerebral artery (MCA) bifurcation in 3 patients, the distal M3 segment in 3 patients, and the anterior temporal artery (ATA; the early cortical branch of the M1 segment) in 1 patient. A total of 10 revascularizations were performed. Three aneurysms were saccular and six aneurysms were fusiform. For the fusiform aneurysms of the M1 segment in 2 patients, superficial temporal artery (STA) trunk-saphenous vein (SV)-MCA bypasses followed by trapping were performed. For the large saccular MCA bifurcation aneurysms in 3 patients, STA-MCA bypasses followed by complete neck clipping, including the revascularized branch with the preservation of the flow of the other branch, were performed in 2 cases, and a STA trunk-SV-MCA bypass secondary to direct neck clipping with the preservation of both M2 branches was performed in 1 case. For the fusiform distal MCA aneurysms, STA-MCA bypasses in 2 patients and in situ MCA-MCA bypasses in 2 patients were performed. In one case involving distal MCA fusiform aneurysm, STA-MCA bypass and MCA-MCA bypass were performed simultaneously. In a case involving fusiform ATA aneurysm, primary reanastomosis after aneurysm excision was performed in 1 patient.

RESULTS: The post-operative 3-month Glasgow outcome scales were good recovery in 6 patients, severe disability in 1 patient, a vegetative state in 1 patient, and death in 1 patient. A follow-up angiography was performed in 6 patients and revealed a patent bypass in 5 patients. In one case treated by direct neck clipping secondary to cerebral revascularization, the angiography obtained 2 weeks later showed graft occlusion, but there were no neurologic symptoms. Among the unfavorable outcomes of 3 patients who did not undergo follow-up angiography, surgery-related morbidity secondary to cerebral infarction was due to the size discrepancy between the donor and recipient vessels in 1 patient with severe disability. In the other 2 patients, the preoperative conditions were Hunt and Hess grade V.

CONCLUSIONS: Cerebral revascularization is a safe and effective technique of treatment for selective cases of complex large or giant aneurysms and unclippable fusiform aneurysms in the MCA.