[A case of multiple aneurysms at the distal portion of the posterior inferior cerebellar artery].

We present a case of multiple aneurysms of the posterior inferior cerebellar artery (PICA) at the distal portion, which is very rare. A 62-year-old woman was admitted to our hospital with complaint of a severe headache. Four-vessel study was carried out and we found one aneurysm in the retromedullary segment of the right PICA. The aneurysm was clipped through the median suboccipital approach. But postoperative angiography showed that aneurysm was not being clipped and the clip was seen about 1 cm proximal to the aneurysm. We concluded that she had two aneurysms and the second operation was performed. The second aneurysm was found about 1cm distal of the one first clipped. The histological finding of the first clipped aneurysm was a degenerative change of slight cellular swelling of the muscle layer. The patient died 10 days after the second operation from fluminant hepatitis and autopsy was not performed. We made a review of the literature about the incidence of multiple aneurysms at the distal portion of PICA.