末端肥大症に合併した大動脈弁狭窄症に対する1治験例

A Case of Aortic Valve Replacement for Aortic Stenosis Associated with Acromegaly

要旨

　末端肥大症に合併した大動脈弁狭窄症(AS)の1例を経験した．患者は慢性腎不全に対し10年の透析歴を有する72歳，女性．6年前より呼吸困難，胸部不快感，動悸が出現し，次第に増強した．精査にて圧較差57mmHgの大動脈弁狭窄症と診断された．17年前に末端肥大症に対する手術を受けていたが，ブロモクリプチン5mg/日の内服にて成長ホルモン(GH)は34.5ng/ml(正常値5ng/ml以下)と高値を示した．大動脈弁は高度の石灰化を伴っており，19mm Carpentier-Edwards弁にて人工弁置換術を施行した．術後3日間IABPを使用し，7日目に人工呼吸器より離脱した．末端肥大症においてはGHの作用により心血管病変が指摘されており，術前からのGHのコントロールが重要であると考えられた．

Summary

　We report a case of aortic valve replacement for aortic stenosis associated with acromegaly. A 72-year-old woman with the complaint of progressive dyspnea and chest pain was admitted to our hospital. She was on hemodialysis because of chronic renal failure. Although 17 years previously she had undergone Hardy's operation with bromocriptine mesilate administration, herpreoperative serum growth hormone(GH) was markedly elevated.

　Cardiac catheterization revealed diffuse hypokinesis on left ventriculography, a pressure gradient of 57 mmHg at the left ventricular outflow tract, and diffuse atherosclerotic changes in the coronary arteries. This data suggested aortic stenosis.

　During the operation, diffuse sclerotic changes were noted on the aortic valves, which were excised, and replaced with Carpentier-Edwards bioprosthesis. An intraoperative intraaortic balloon pump was required because of low cardiac output after discontinuation of extracorporeal circulation. She experienced congestive heart failure after the operation. Histopathological findings showed myxomatous, calcified and hyalinized changes with fibrous thickening of the aortic valves.

　Surgical cases of heart diseases associated with acromegaly are rare in Japan. Preoperative control of serum GH level is thought to be important.