Contralateral Approach to Bilateral Middle Cerebral Artery Aneurysms

Abstract

BACKGROUND: Bilateral aneurysms located between the 2 middle cerebral artery (MCA) bifurcations may be approachable through a single unilateral approach. OBJECTIVE: To identify anatomic parameters based on imaging that would favor a contralateral approach. METHODS: From January 1998 to December 2013, we retrospectively identified 173 patients with bilateral intracranial aneurysms. Fifty-one patients had bilateral MCA aneurysms. A total of 38 patients underwent a single craniotomy with a contralateral microsurgical approach (group 1 or contralateral group) and 13 patients underwent bilateral craniotomies (group 2 or bilateral group). For both groups, we analyzed aneurysm characteristics, morphology, size, projections, and distance to the contralateral corridor, as well as surgical time, outcome, and postoperative complications. RESULTS: All aneurysms approached contralaterally were unruptured and without wall calcifications. Of the contralaterally approached aneurysms, 97% were smaller than 14 mm. The median length of the contralateral A1 was 13.2 mm (range: 6–19.8 mm) and the median length of the contralateral M1 was 14.2 mm (range: 4.6–21 mm). The contralateral group had a good postoperative outcome (modified Rankin Scale 0–3) in 80% of ruptured cases and 86% of unruptured cases. The median surgical time was 120 minutes (range: 75–255 minutes), 43% shorter than the bilateral group. CONCLUSION: The contralateral approach for bilateral MCA aneurysms in selected patients is feasible in experienced hands, with acceptable morbidity and mortality. The contralateral approach requires a meticulous preoperative analysis of the characteristics of the aneurysms to be clipped and of the anatomic constraints of the microsurgical operative corridor.