Surgical Experience of Distal Middle Cerebral Artery Aneurysm Rupture

원위부 파열 중대뇌동맥류의 수술적 경험

Objective : Distal middle cerebral artery (MCA) aneurysms are the least frequent aneurysms of the MCA, and they represent about 1.1 to 5% of all MCA aneurysms. Patients with ruptured distal MCA aneurysms generally have a poor clinical outcome. The purpose of this article is to review the characteristics of distal MCA aneurysms to avoid the complications of microsurgical dissection and clipping of distal MCA aneurysms. Methods : A total of 1187 patients with ruptured aneurysms were treated at our hospital between January 1997 and May 2008. All patients underwent surgical procedures. Computed tomography (CT) revealed rupture of distal MCA aneurysms in 15 (1.26%) patients. The location of the aneurysm were the M2 (insular) segment in seven patients, the M2-3 junction in three and the M3 (opercular) segment in five. Brain CT images revealed the presence of both subarachnoid hemorrhage (SAH) and intracranial hemorrhage (ICH) in 11 of 15 (77.3%) patients, with a mean ICH volume of 14.5 cc (range : 5 to 32 cc). Rebleeding occurred in 7 out of the 15 (46.7%) patients. Results : All the patients underwent early surgical procedures, including clipping in seven, trapping in two, bypass surgery in four, Guglielmi detachable coil embolization in one and exploratory craniotomy in one patient. The aneurysm had a fusiform appearance in 9 out of 15 cases (60%), and the mean size of the aneurysm was 10.4 mm (range : 2 to 35 mm). Three patients died due to severe brain swelling (20%). Conclusion : In this study, distal MCA aneurysms had a relatively fusiform shape as well as high rates of rebleeding and ICH. A good clinical outcome was associated with early surgery for adequately controlling brain swelling and preventing rebleeding.