Microsurgical Management of Middle Cerebral Artery Aneurysms: Clinical Features and Outcomes

Middle Cerebral Artery Aneurysms

Abstract

Background: Middle cerebral artery (MCA) aneurysms are a frequent cause of spontaneous subarachnoid hemorrhage (SAH) and pose distinct surgical challenges because of their anatomical location and association with intracerebral hematomas. This study analyzed the clinical features, microsurgical management, and outcomes of MCA aneurysms to identify prognostic factors and optimal surgical timing.

Methods: We retrospectively reviewed 107 patients with MCA aneurysms who underwent microsurgical clipping at a single neurosurgical center between 1992 and 2002. Demographic characteristics, risk factors, clinical presentation, radiological findings, aneurysm morphology and location, and surgical details were evaluated. All patients were treated using a standard pterional transsylvian approach. Clinical severity was graded using a modified Hunt and Hess/Yasargil classification, and hemorrhage extent was assessed with Fisher CT grading. Outcomes at discharge and follow-up (≥6 months, up to 5 years) were categorized as good recovery, moderate disability, severe disability, or death.

Results: MCA aneurysms accounted for 29.2% of all intracranial aneurysms treated during the study period. The cohort included 107 patients (60.7% female) with a mean age of 52.3 years; 80% were between 40 and 70 years old. Thunderclap headache was the most common presenting symptom (72.8%), followed by sudden loss of consciousness (13.1%) and focal neurological deficits (11.2%). Hypertension was the predominant risk factor (62.6%). A total of 116 MCA aneurysms were identified: 94% were located at the bifurcation, 5.2% at the distal M1 segment, and 0.8% at the M2 segment. Nineteen patients (17.7%) had multiple aneurysms, including bilateral or multiple MCA aneurysms in 7.4%. Among 133 total aneurysms, 129 (97%) were successfully clipped in single or staged procedures; four were not clipped (three in elderly poor-grade patients and one small aneurysm treated with coagulation). Temporary arterial occlusion was required in 17.8% of cases. Overall outcomes were favorable in 81.3% of patients, while 11.2% had moderate disability, 1.8% severe disability, and mortality was 5.6%. All patients presenting with Grade 0–IIa achieved good recovery, whereas poor-grade patients (Grades IV–V) had a mortality rate of 66.6%. Patients younger than 50 years had better outcomes than those aged ≥50 years (92.6% vs 74.2% good recovery). Optimal outcomes were observed when surgery was performed 8–21 days after SAH.

Conclusion: Microsurgical clipping of MCA aneurysms yields excellent outcomes, particularly in younger patients and those presenting with good neurological grade. Preoperative clinical status and age are the strongest predictors of outcome. Carefully timed surgery after the acute phase of SAH appears to reduce complications related to vasospasm and rebleeding, supporting meticulous microsurgical management as a durable and effective treatment strategy.