Surgical Clipping of a Ruptured Distal Anterior Inferior Cerebellar Artery Aneurysm: A Technical Note

Aneurysms of the distal anterior inferior cerebellar artery (AICA) are uncommon. They can present with subarachnoid hemorrhage (SAH), cerebellopontine angle syndrome, or a combination of the two. We describe the technique and nuances of microsurgical clipping of a ruptured distal AICA aneurysm using a retrosigmoid approach. After performing the craniotomy, the AICA was exposed in a distal to proximal fashion and the aneurysm and the proximal parent vessel were identified. After establishing proximal control, a clip was placed across the neck of the aneurysm to obliterate it while maintaining flow within the parent vessel. Finally, the flow within the parent vessel was confirmed and the final clip position was checked to ensure that it was not compressing any of the cranial nerves in the vicinity. The aneurysm was completely obliterated, and the parent vessel remained patent. Distal AICA aneurysms are rare and challenging to treat. The retrosigmoid approach is commonly used to treat these aneurysms. Careful planning, which includes studying the vascular anatomy and the aneurysm characteristics, and proficient execution of the procedure can increase the safety and improve outcomes of surgical clipping of these aneurysms.