Feasibility and safety of partial resection of the anterior insular cortex for microsurgical treatment of middle cerebral artery aneurysms located in the limen recess: patient series

BACKGROUND: When performing clip ligation of superior projecting aneurysms of the proximal (M1) segment of the middle cerebral artery (MCA), meticulous sylvian fissure dissection alone may be inadequate for safe clip application, especially in cases in which the aneurysm is buried in the limen recess, since the limen insulae may be positioned lateral to the aneurysm. In the present patient series, the authors present their surgical technique for clip ligation of aneurysms located in the limen recess, with partial resection of the limen insulae. OBSERVATIONS: A retrospective analysis of patients who had undergone clip ligation of MCA aneurysms located at the limen recess at a single institute was performed. Patients with angiographic and clinical follow-up data were considered eligible. A total of 11 aneurysms (4 ruptured and 7 unruptured aneurysms) in 11 patients were evaluated. Postoperative ischemic lesions were observed on images obtained within 1 week after surgery in 5 (45.5%) patients who had undergone partial resection of the limen insulae, although none of them presented with neurological deterioration. LESSONS: Partial resection of limen insulae may be feasible to avoid severe ischemic complications following clip ligation of M1 aneurysms embedded in the limen recess.