前交通動脈瘤を合併したPersistent primitive arteryの2例

Two Cases of Persistent Primitive Artery Associated with Anterior Communicating Aneurysm

I．はじめに

　persistent primitive trigeminal artery（PTA）は，内頸動脈—脳底動脈吻合遺残のうち最も頻度が高く，脳血管撮影上，0.1-0.3％にみられ^{4,12,14,17）}，persistent primi—tive hypoglossal artery（PHA）はその1／6の頻度でみられるといわれている^12,17）．persistent primitive arteryは，それ自体臨床症状を呈することは少なく，くも膜下出血，脳腫瘍，頭部外傷などの疾患で脳血管撮影が行われたときに，偶然発見されるものが多い．われわれは，くも膜下出血で発症し，脳血管撮影で前交通動脈瘤とpersistent primitive arteryの合併した2例を経験したので報告する．

Two aneurysm patients who have persistent primi-tive artery are reported. Both patients were admitted to our hospital under the diagnosis of subarachnoid hemorrhage. Carotid angiograms revealed saccular aneurysms in the anterior communicating artery. One case had the right persistent trigeminal and the other had the right persistent hypoglossal artery. Both pa-tients were treated by aneurysmal neck clipping suc-cessfully.

The incidence of association of persistent primitive trigeminal artery with intracranial vascular disease is 25%, in which 14% of cases have the intracranial aneurysms.