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

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.