Usefulness of Orbitocranial Approach in Neck Clipping of Aneurysms Arising from Middle Cerebral Artery Proximal to the Limen Insulae: A Case Series

Abstract

Neck clipping of the aneurysms arising from the middle cerebral artery (MCA) proximal to the limen insulae is often difficult because of difficulties in securing a bright and wide operative field to observe the aneurysms and surrounding structures, such as the anterior perforated substance, lenticulostriate arteries, and early frontal branch. Our objective was to determine the usefulness of the orbitocranial approach in neck clipping of the aneurysms arising from the MCA proximal to the limen insulae. This prospective study included 7 patients who underwent neck clipping of aneurysms arising from the MCA proximal to the limen insulae through the orbitocranial approach. In addition to conventional pterional craniotomy, the superiolateral orbital rim was resected with a 1-piece fashion. Its procedures, complications, and outcomes were reviewed. Removal of the superolateral orbital rim facilitated a bright and wide observation from the skull base side. It was much easier to identify the anterior perforated substance, lenticulostriate arteries, and early frontal branch around the aneurysm through the orbitocranial approach than through the conventional pterional approach. Neck clipping could be performed completely and safely in all cases. The orbitocranial approach to aneurysms arising from the MCA proximal to the limen insulae provides us a bright and wide operative field compared with the conventional pterional approach, which is useful to secure complete and safe neck clipping by avoiding cerebral contusion and unexpected obstruction of the early frontal branch.