汎下垂体機能低下症を呈した未破裂内頚動脈瘤の治療後，内分泌学的機能の改善が得られた1例

A Case of Unruptured Internal Carotid Artery Aneurysm with Improved Endocrinological Function after Treatment

Ⅰ．はじめに

　成人下垂体機能低下症の原因として，本邦の報告では腫瘍性病変が多く，その内訳は下垂体腺腫が27.4%であり，次いで特発性21.5%，頭蓋咽頭腫13.3%，胚芽腫7.3%, Sheehan症候群6.4%と報告されている¹⁸⁾．一方で，頭蓋内動脈瘤が原因で汎下垂体機能低下症を呈することは0.17%と稀であり⁶⁾，内分泌機能の回復に関するまとまった報告はなく，詳細は不明である^6,13,16)．今回われわれは，汎下垂体機能低下症を呈した未破裂内頚動脈瘤の治療後，内分泌学的機能の改善が得られた1例を経験したので報告する．

　We experienced a case of unruptured internal carotid artery aneurysm improved endocrinological function after the treatment. A 68-year-old woman was admitted to our hospital complaining of general fatigue, dizziness, and decreased visual acuity. Radiological examination revealed unruptured large aneurysm at the right anterior carotid artery compressing on the pituitary gland. We underwent right STA-MCA bypass and trapping of right internal carotid artery. Post-operative course was uneventful. Although visual function was not improved, her endocrinological function was improved 8 months after surgery by thrombosed and shrunken aneurysm. The mechanism of panhypopituitarism due to aneurysm has been suggested to involve mechanical compression on the pituitary gland, pituitary stalk, or hypophyseal artery. Although it was unclear about the improvement of endocrine function after the treatment of aneurysm, some cases could recover the hypopituitarism after enough follow-up period.