胸部大動脈瘤破裂自然経過の1例

Natural history of ruptured aneurysm of the thoracic aorta.: A case report

　近年，平均寿命の延長や食生活の変化にともない，わが国でも大動脈瘤の手術例は増加の傾向にあり^1），手術成績も向上してきたが，破裂瘤ではその成績はいまだ不良である。大動脈瘤の自然予後をみると，Estesは腹部大動脈瘤102例での臨床診断確定後の5年生存率は19％^2），Joyceらは胸部大動脈瘤107例での5年生存率は50％^3）であると述べている。死因の大部分は瘤破裂であり，特に胸部大動脈瘤では胸腔内へのopen ruptureによって急死することが多い。胸部大動脈瘤破裂であっても破裂が縦隔内へ起こった場合には急死を免れることもあるが，長期生存例の報告はきわめてまれである。われわれは胸部下行大動脈瘤破裂例で急死を免れ，手術適応としたものの手術を拒否されたため，自然経過をみるなかで多彩な臨床症状を呈した1例を経験したので，その臨床経過を若干の文献的考察を加えて報告する。

This report describes the natural course of a patient who developed ruptured aneurysm of the thoracic aorta. He survived for three months and it is rare to get such a long term survival.

A 76-year-old male with thoracic aortic aneurym was admitted complaining of severe back pain. Chest X-ray film and computed tomographty were interpreted as showing ruptured thoracic aortic aneurysm. Emergency operation should be performed, but he and his family did not agree to operate on. Four weeks after admission, he was suffered from dysphagia and dyspnea due to extrapleural hematoma and thoracic aneurysm itself clinically. His condition was getting severe progressively and died of respi-ratory disorders three months later. Autopsy reveal-led bilocular saccular aneurysm at descending thora-cic aorta just distal left subclavian artery. A slit was observed at the smaller aneurysm, but it was uncertain to which direction rapture had develo-ped.

Prognosis of ruptured aneurysm of the thoracic aorta is extremely poor even if sudden death can be avoided. Therefore surgical treatment should be carried out to save the patient.