2026 年 13 巻 p. 311-316
Aneurysms associated with arteriovenous malformations occur in up to 20% of cases, but distal anterior inferior cerebellar artery aneurysms associated with arteriovenous malformations are extremely rare. We report a case of a ruptured distal anterior inferior cerebellar artery aneurysm associated with a cerebellar arteriovenous malformation in a 71-year-old man presenting with subarachnoid hemorrhage. Digital subtraction angiography revealed a cerebellar arteriovenous malformation supplied mainly by the right anterior inferior cerebellar artery and a fusiform aneurysm located at the meatal loop within the internal auditory canal. The aneurysm was considered the most likely rupture point based on the hemorrhage distribution and angiographic findings. Endovascular treatment was attempted to prevent re-rupture. Due to challenging distal catheterization and unattainable complete coil embolization of the aneurysm, the aneurysm and a short proximal segment of the parent artery were occluded. Postoperatively, the patient developed a mild hearing loss without brainstem infarction. Subsequent arteriovenous malformation resection via lateral suboccipital craniotomy led to complete obliteration. Parent artery occlusion reduced arteriovenous malformation flow and served as preoperative embolization to facilitate safe surgical removal. This case highlights the importance of individualized treatment strategies for rare distal anterior inferior cerebellar artery aneurysms associated with arteriovenous malformations and suggests that parent artery occlusion with subsequent staged arteriovenous malformation resection can be an effective approach.
