Minimally invasive treatment strategy for partially thrombosed anterior inferior cerebellar artery aneurysm: A case report

Background: Partially thrombosed anterior inferior cerebellar artery (AICA) aneurysms are extremely rare; thus, no established therapeutic approach exists. Case Description: We report a large, partially thrombosed AICA aneurysm and discuss its therapeutic nuances. The aneurysm was asymptomatic; therefore, we aimed to treat it through a minimally invasive procedure. The aneurysm was of fusiform type and the proximal neck of the aneurysm was positioned at midline in front of the brainstem. To approach the neck, posterior transpetrosal approach is recommended. However, this approach can be invasive; thus, we performed distal clipping of the aneurysm using transcondylar fossa approach with occipital artery-AICA bypass to avoid ischemia of the AICA territory. Although the size of the aneurysm initially increased, it subsequently decreased. Conclusion: This is a rare case report describing the long-term clinical course after distal clipping in detail. We showed that traditional microsurgical techniques can be applied to treat patients with new, minimally invasive treatment strategies.