Successive Development and Rupture of Blister-Like Anterior Communicating Artery Aneurysms at Mirror Locations.

This is the first report of the successive development and rupture of blister-like anterior communicating artery (ACoA) aneurysms at mirror locations with a short interval. A 49-year-old man presented with an angiogram-negative subarachnoid hemorrhage with significant basal frontal interhemispheric blood. Surgical exploration revealed a blister-like aneurysm on the left side of the superior wall of the ACoA, which was treated using a microsuturing technique. On the 18th day after the initial subarachnoid hemorrhage, the second operation due to another angiogram-negative hemorrhage revealed a de novo blister-like aneurysm with a small blood clot on the posterosuperior wall of the ACoA close to the right A1/A2 junction. The rupture point and ACoA on the right side were occluded using an aneurysm clip. Follow-up digital subtraction angiogram at 4 years and computed tomography angiogram at 14 years after the surgery showed no recurrence or associated abnormality.