Characteristics and management of ruptured distal middle cerebral artery aneurysms.

OBJECTIVE: Distal middle cerebral artery (dMCA) aneurysms are very rare with a reported frequency of 2-6%. Typically, patients with ruptured distal MCA aneurysms have poor clinical outcomes because often there is both a subarachnoid haemorrhage (SAH) and an intracerebral haematoma (ICH). The goals of this study were to identify the characteristics of the distal MCA aneurysms and evaluate the optimal treatment for a good outcome.

METHODS: The clinical, neuroradiological and operative records of 8 patients with a ruptured distal MCA aneurysm who underwent surgical management were reviewed retrospectively. The outcomes were presented according to the Glasgow Outcome Scale (GOS).

RESULTS: The clinical characteristics of the patients with ruptured dMCA aneurysms included the following: (1) a fusiform appearance in five out of eight (63%) patients. (2) Mean aneurysm size of 9.4 mm (range 2-35 mm). (3) The location being M2 (insular segment) in three, M2-3 junction in three, and M3 (opercular segment) in two patients. (4) Brain CT images revealed both SAH and an ICH in six of eight (75%) patients with the mean size of the ICH being 10 cc (range 5-25 cc). (5) Re-bleeding occurred in four out of eight (50%) of patients. All patients underwent early surgical treatment and the procedures used for surgical repair were, clipping in five patients, trapping in two, and trapping with end-to-end bypass surgery in one patient. Clinical outcomes were poor in two patients (death) due to severe brain swelling.

CONCLUSIONS: In this study, dMCA aneurysms had a fusiform shape and a high re-bleeding rate; if ruptured, there was generally ICH and SAH. A good clinical outcome was associated with adequate control of brain swelling and early surgery to prevent re-bleeding.