Rhabdomyolysisを伴った若年性解離性大動脈瘤の1例

A case of dissecting aortic aneurysm accompanied by rhabdomyolysis

　1941年のBywaters^1）の外傷による急性腎不全の報告以来，筋細胞の融解，壊死によって血中に遊出されるミオグロビンと急性腎不全との関連がまずCrush syn—dromeとして広く知られるようになった。その後，外傷以外にもスポーツ，薬物，代謝性異常，感染，筋疾患など種々の原因による高ミオグロビン血症が骨格筋細胞の融解を意味するRhabdomyolysisとして知られるようになり，主に諸外国においてそれらの病態に続発したRhabdomyolysisによる急性腎不全のまとまった数の症例報告もみられるようになった^2〜4）。また，近年radioimmunoassay法による血中，尿中ミオグロビンの定量が簡単に行えるようになり，最近では我が国においても様々の原因に続発したRhabdomyolysisによる急性腎不全の報告もいくつかみられるようになったが^5〜9），解離性大動脈瘤に続発したRhabdomyolysisの報告はほとんどみあたらない。

　今回，我々は若年者に解離性大動派瘤を発症し，同時にRbabdomyolysisを来たした1例を経験したので，貴重なものと考え，報告する。

A 30-year-o1d male was brought to the emergency room with severe anterior chest pain, backache andlumbago. On physical examination, the blood pres-sure was 108/70 mmHg. No abnormal peripheral arterial pulses were found. A diastolic blowing mur-mur was not audible along left sternal border. An enhanced computed tomography of the thoracic and abdominal aorta did not demonstrate clear evi-dence for dissecting aortic aneurysm. Serum GOT, GPT, LDH and myoglobin were markedly elevated. He developed acute renal failure (ARF) in asso-ciation with rhabdomyolysis and hemodialysis was performed. He recovered once from ARF, but again he became anuric. The chest X-ray film revealed remarkable cardiomegaly and pulmonary congestion. Physically a diastolic blowing murmur appeared. A (M-mode) echocardiograph showed aflattering of mitral valve. No evidence of an intimal flap was seen. Congestive heart failure due to aortic regurgitation was considered as etiolgy of ARF. Heart failure was refractory to medical therapy. After all, he was sent to operation room. During surgery, a circumferential intimal tear with widen-ing of aortic root and separation of the aortic cusps was noted. He underwent successful surgical replace-ment of the ascending aortic valve. ARF was im-proved in the immediate postoperative period. Renal biopsy was not performed.

A discussion of the rhabdomyolysis related to the dissecting aortic aneurysm and a literature review pertaining to these complications are pre-sented.