The Art of Cerebral Revascularization: an Illustrative Case Series of Bypass Techniques for Complex Intracranial Aneurysms

IntroductionComplex intracranial aneurysms (CIAs) comprise a subset of lesions with defiant vascular architecture, difficult access, and prior treatment. Surgical management of CIAs is often challenging and demands an assessment on a case-by-case basis. The generational evolution of bypass surgery has offered a long-standing potential for effective cerebral revascularization. Herein, we aim to illustrate a single-center experience treating CIAs.MethodsThe authors conducted a retrospective analysis of clinical records of patients treated with cerebral revascularization techniques at Hospital Nacional Dos de Mayo, Lima, Peru during 2018-2022. Relevant data were collected, including patient history, aneurysm features on imaging, preoperative complications, the intraoperative course, aneurysm occlusion rates, bypass patency, neurological function, and postoperative complications.ResultsSeventeen patients (70.59% female; median age: 53 years) with 17 CIAs (64.7% saccular; 76.5% ruptured) were included. The most common clinical presentation included loss of consciousness (70.6%) and headaches (58.8%). Microsurgical treatment included first, second, and third-generation bypass. In 47.1% of cases, an anastomosis between the superior temporal artery (STA) and the M3 segment was predominantly used, followed by an A3-A3 bypass (29.4%), STA-M2 bypass (17.6%), and an external carotid artery to M2 bypass (5.9%). The intraoperative aneurysm rupture rate was 11.8%. Postoperative complications included ischemia (40%), cerebrospinal fluid fistulas (26.7%), and pneumonia (20%). At hospital discharge, the median Glasgow Coma Scale score was 14 (range: 10-15). At the six-month follow-up, 82.4% of patients had a modified ranking scale (mRS) score ≤2, bypass patency was present in all cases, and the morbidity rate was 17.6%.ConclusionCIAs represent a spectrum of defiant vascular lesions with a poor natural history. Bypass surgery offers the potential for definitive treatment. Our case series illustrated the predominant role of cerebral revascularization of CIAs with a critical case-by-case approach to provide optimal outcomes in a limited-resource setting.