Proximal Middle Cerebral Artery Aneurysms: Microsurgical Management and Therapeutic Results

BACKGROUND: Management of proximal (M1) middle cerebral artery (MCA) aneurysms can be challenging. Because of the diversity of aneurysm morphology and location of M1 aneurysms, the surgical strategy should be tailored to each individual case, especially for complex cases. We assessed the safety and efficacy of an algorithmic strategy for the management of M1 aneurysms. METHODS: A prospective single-center study of M1 aneurysms treated with microsurgery was performed. Our algorithmic strategy was determined by the location and complexity (e.g., size, shape) of the aneurysms. The surgical modalities included neck clipping, aneurysm resection and/or trapping, and proximal occlusion with revascularization. The clinical and radiographic data were analyzed. RESULTS: From January 2007 to March 2017, 92 proximal MCA aneurysms in 92 patients were treated microsurgically. Aneurysm treatment techniques included clipping in 55, proximal occlusion in 21, aneurysm resection in 11, and trapping in 4. Bypass techniques included 2 anterior temporal artery reconstructions, 5 middle cerebral bifurcation reconstructions, 4 parent artery reanastomoses, 2 interpositional bypasses, 25 high-flow bypasses, and 7 medium-flow bypasses. Overall, good outcomes (modified Rankin scale score, 0-2) were seen in 49 of 92 patients (53.3%) at discharge and in 79 of 91 (86.8%) at the last follow-up visit. On the latest angiogram, 78 of 90 aneurysms (86.7%) had been completely occluded without a remnant. Bypass patency was confirmed in 38 of 43 bypass procedures. CONCLUSIONS: Our present treating strategy might provide a benefit for patients with proximal MCA aneurysms.