Ruptured fusiform callosomarginal artery aneurysm treated by excision and end-to-end reconstruction - Case report,...

Aneurysms of the callosomarginal artery (CMA), a major branch of the pericallosal artery, are rare and typically located at the CMA-pericallosal bifurcation. These distal anterior cerebral artery (DACA) aneurysms comprise 1.5 %-9 % of all intracranial aneurysms and are usually saccular. Fusiform aneurysms in this location are exceedingly uncommon and present unique management challenges due to their morphology and location. This report describes the management of a ruptured fusiform CMA aneurysm and discusses key technical aspects of microsurgical planning and reconstruction.

A 60-year-old smoker presented with a one-week history of severe headache, nausea, and vomiting. Imaging revealed a ruptured fusiform aneurysm of the distal callosomarginal artery. Given the aneurysm's location and morphology, open surgical treatment was chosen. The aneurysm was excised, and after careful mobilization, the affected vessel was reconstructed with a tension-free end-to-end anastomosis. Histological and microbiological analysis of the aneurysm and abnormal arachnoid showed no signs of mycotic origin. A cardiological evaluation ruled out infective endocarditis. Postoperative recovery was uneventful, and follow-up angiography confirmed complete aneurysm resection with vessel patency. The patient was started on lifelong antiplatelet therapy and remained asymptomatic with full functional recovery at the one and two year follow-up.

While endovascular options are expanding, distal aneurysms in small-caliber vessels remain inaccessible in most cases. Direct microsurgical vessel reconstruction offers a durable and definitive treatment option in carefully selected cases. Microsurgical training and expertise in vascular reconstruction are essential for managing complex vascular lesions that fall beyond the reach of endovascular therapy.