Considerations in the surgical treatment of superior-wall type aneurysm at the proximal (M1) segment of the middle cerebral artery

Abstract

Objective: To present our experience and analyze the risks of neck clipping for superior-wall type aneurysms of the proximal segment of the middle cerebral artery (M1-Sup aneurysm).

Methods: Of 14 patients with M1-Sup aneurysms, 4 suffered postoperative infarctions in the territory of the lenticulostriate arteries (LSA) or fronto-orbital arteries. We re-examined our intraoperative findings and clinical records in an effort to identify possible causes.

Results: The patency of the LSA was confirmed at the end of surgery in all 14 cases. We posit that temporary occlusion of the LSA by a permanent clip resulted in delayed obstruction of the LSA in 3 patients. Other possibilities we considered were relatively long temporary occlusion of the M1, slipping of the clips and twisting of the clip blades after release of the brain retractors.

Conclusion: M1-Sup aneurysms are some of the most complicated aneurysms; they carry the risk of perforator injury during neck clipping. Surgical considerations to avoid perforator injury are discussed.