Aneurysm of the anterior inferior cerebellar artery (AICA) associated with high-flow lesion: report of two cases and review of literature.

Item does not contain fulltextOBJECTIVE AND IMPORTANCE: Although aneurysms of the anterior inferior cerebellar artery (AICA) are rare lesions, their occurrence in combination with high-flow lesions in the same arterial territory is even more striking. Two cases of an AICA aneurysm in combination with a high -flow lesion are described. CLINICAL PRESENTATION: In one case, a 52-year-old female presented with cerebellar syndrome as the result of a left-sided cerebellar tumor. Angiography revealed a highly vascularized tumor and a broad-based aneurysm at the offspring of the left AICA. In the second case, a 17-year-old female presented with a right-sided cerebellar hemorrhage. Angiography revealed a large peripheral AICA aneurysm and a distal arteriovenous malformation (AVM) fed by the AICA. INTERVENTION: In the first case, a left lateral suboccipital craniotomy was performed and a highly vascularized tumor was removed. The AICA aneurysm could not be adequately clipped and was subsequently wrapped with muscle and reinforced with fibrin glue. Pathological examination of the tumor revealed a hemangioblastoma. Five years after surgery, the patient experienced a subarachnoid hemorrhage. Subsequent vertebral angiography revealed local enlargement of the known AICA aneurysm just at the superior aspect, but the patient refused further treatment. In the second case, the patient sustained a novel cerebellar rebleed while awaiting surgery. A right-sided lateral retromastoid suboccipital craniotomy was performed and the AICA aneurysm could be successfully clipped. More peripherally, the AVM with two draining veins could be totally removed. Postoperative angiography revealed no residual aneurysm or AVM. CONCLUSION: Several aspects of these cases are discussed, such as the rare occurrence of AICA aneurysm and the contribution of high-flow lesions to the genesis of the AICA aneurysms