高度左室機能低下症例に対するA-Cバイパス術の手術成績ならびに手術効果に関する検討

Results of aortocoronary bypass surgery for patients with severe left ventricular dysfunction

　虚血性心疾患に基因する高度左室機能低下例に対する大動脈冠動脈バイパス手術（A-Cバイパス術）の手術成績は，手術手技の改善，心筋保護法の確立，補助循環の発達，術後管理の向上，などにより近年著明に改善し，比較的安全に手術が行なわれるようになった^1,2）。しかしながら，これらの症例は術前に比較的広範囲心筋梗塞の既往を有することが多く，本手術が有効であるか否かの点で，不明な点が存在する。

　今回，虚血が心疾患に基因する高度左室機能低下例（左室駆出率＜0.4）に対するA-Cバイパス術症例22例について，A-Cバイパス術の有効性を中心に，その手術成績を検討した。

In this paper, we evaluated the efficacy of aorto-coronary bypass surgery in the patients with severe left ventricular dysfunction. Between 1974 and 1983, 22 patients with left ventricular ejection fraction (EF) less than 0.4 underwent aortocoronary bypass surgery.

Operative mortality was 14 percent, but there was no operative death in patients after 1979. Actuarial survival rate was 86.4 percent 9 years after operation. Clinical improvement were obvious in 18 patients. Eleven of them were in NYHA class I after operation.

Postoperative hemodynamic studies and coronary sinus blood flow measurements were carried out at rest and during exercise in 7 patients whose stenotic lesions in left anterior descending arteries were completely revascularized. In left ventricular minute work and coronary sinus blood flow during exercise, there were no significant differences between in these 7 patients and in normal control group. Left ventricular endodiastolic pressure during exercise was significantly higher than that in normal control.

These data indicated that aortocoronary bypass surgery was effective in patients with severe left ventricular dysfunction.