Giant, unruptured, partially thrombosed right MCA aneurysm treated with 2 bypasses and excision.

Abstract

Aneurysms of the middle cerebral artery (MCA) account for up to 40% of all unruptured intracranial aneurysms [1-3] and 14% to 20% of ruptured ones. [4-5] Giant MCA aneurysms are rare, representing 10% of cases [6], but carry an aggressive natural history, with the UCAS Japan study reporting an annual rupture rate of ∼ 17%. [7]. Additionally, unruptured giant MCA aneurysms can present with neurological symptoms including headache, focal neurological deficit, seizure, or ischemia infarcts. Here we report a 58-year-old male with a history of alcohol abuse, hypertension, diabetes, and smoking that presented after a first-time seizure. Imaging revealed an unruptured, giant (2.9 cm), partially thrombosed right MCA aneurysm. A microsurgical approach using clipping and bypass was planned due to the aneurysm's complexity. Six weeks later, the patient underwent a right frontotemporal craniotomy with radial artery graft (RAG) extraction, followed by two bypasses: an M2-M2 intracranial bypass and a right external carotid to M2 bypass using the RAG. The aneurysm was successfully excised. Otolaryngology assisted with the RAG extraction during the craniotomy and neck dissection. This case highlights the technical complexities involved in managing giant aneurysms via microsurgical technique, including appropriate pre-operative strategy development. Informed consent from next of kin as well as IRB approval (IRB #23.0720) was obtained for this retrospective study of patients with cerebrovascular disease.