Pial arteriovenous fistulas (AVFs) are known as rare cerebrovascular lesions. They are composed of ≥ 1 arterial feeding vessels and a single draining vein that usually has high perfusion pressure and generally occur in infants. Cases involving adults are very rare and the developmental mechanisms and natural history of these lesions remain unknown. The authors present a case of multiple pial AVFs in an adult in whom the lesions developed after radiosurgical treatment of dural AVFs. Direct disconnection of pial arterial supplies was performed, and the abnormal shunts were successfully eliminated. The authors report the clinical course of this case and discuss the characteristics of and treatment strategy for multiple pial AVFs, reviewing the published literature.
Atsushi Saito, Takayuki Sugawara, Shigeki Mikawa, Yousuke Akamatsu, Heisuke Saito and Hirofumi Seki
Yousuke Akamatsu, Takayuki Sugawara, Shigeki Mikawa, Atsushi Saito, Sadafumi Ono, Kazuo Takayama, Hidefumi Jokura and Hirofumi Seki
A 75-year-old woman underwent Gamma Knife surgery (GKS) for a vestibular schwannoma. Eight years after GKS, she suffered sudden onset of headache. Computed tomography revealed diffuse subarachnoid hemorrhage around the cisterns of the posterior fossa. Right vertebral artery angiography showed an aneurysm arising from the lateral pontomedullary segment of the left anterior inferior cerebellar artery. The aneurysm was not located at a branching site. Trapping of the distal anterior inferior cerebellar artery aneurysm was performed, and the aneurysm was removed. The pathological features of this aneurysm are discussed. This aneurysm was diagnosed as a pseudoaneurysm pathologically. This is the first report of aneurysm formation with pathological findings following GKS for a vestibular schwannoma.