Flow Diverter Treatment for Ruptured Dissecting Aneurysm at A1-A2 Junction of the Anterior Cerebral Artery in a Young Adult: A Case Report.

Ruptured dissecting aneurysms (DAs) of the anterior cerebral artery (ACA), particularly at the A1-A2 junction, are rare and diagnostically challenging, especially in young patients. Conventional treatment options may be limited due to anatomical constraints and the lesion's fragility. We report the case of a 23-year-old male who presented with diffuse subarachnoid hemorrhage and seizure. Initial imaging failed to identify the bleeding source. On follow-up, computed tomography angiography revealed subtle findings suggestive of a dissection at the right A1-A2 junction, which was subsequently confirmed by digital subtraction angiography. Considering the lesion's morphology and location, the aneurysm was treated with a flow diverter (Pipeline Flex with Shield Technology) following clinical stabilization. The patient recovered without neurological deficits and was discharged in good functional condition. This case highlights the potential of flow diversion as an effective treatment strategy for ruptured DAs in the distal ACA. Early recognition through repeat imaging and individualized multidisciplinary planning may contribute to favorable outcomes in anatomically complex lesions.