Treatment strategies for subarachnoid hemorrhage in a distal basilar dolichoectatic aneurysm: illustrative case.

backgroundFusiform aneurysms of the distal basilar artery are challenging, with high morbidity and mortality. Brainstem perforating vessels, the lack of an aneurysm neck, critical anatomical location near the brainstem, and progression to a large size make any treatment difficult. They are usually treated in an elective planned setting. An acute rupture poses extra challenges. Treatment options are surgical or endovascular. Endovascular treatments have revolved around flow diversion, although given the irregular lumen, this is difficult. Open microsurgical techniques center around bypass and parent vessel occlusion. OBSERVATIONS: A 54-year-old man was admitted to the authors' hospital 4 days after experiencing a subarachnoid hemorrhage from a distal basilar fusiform aneurysm. The rupture point was clipped acutely. The aneurysm rupture point recurred quickly and required definitive treatment of the parent fusiform aneurysm with bypass and parent artery clipping. LESSONS: This case illustrates challenging decision-making in the management of an acute subarachnoid hemorrhage from a complex aneurysm. The case was managed surgically with early treatment of the acute rupture and planned later definitive treatment of the parent aneurysm. Endovascular options are also discussed. https://thejns.org/doi/10.3171/CASE25895.