[Myocardial protection for cardiac reoperations in patients with valvular disease]

In cardiac reoperations, the less dissection needed, the less potential blood loss from divided epicardial adhesions and the less trauma to the heart. However, minimal cardiac dissection may result in inadequate topical cooling. Therefore the optimal delivery of cardiac solution has a great influence upon postoperative myocardial function in cardiac reoperations. We have examined the effect of the modified Buckberg's method compared to that of simple cold blood cardioplegia in valvular reoperations. In the cases of redo aortic valve procedures, antegrade-retrograde delivery of cardioplegic solution was done in the modified Buckberg's method. It was superior to simple cold blood cardioplegia in terms of the doses of dopamine needed when weaning from cardiopulmonary bypass and the ratio of spontaneous beating after aortic declamping. Nevertheless, myocardial protection measures for hypertrophied myocardium have not yet been established. In particular, reoperations for hypertrophied hearts pose many problems for cardiac surgeons. To achieve better cardiac function postoperatively, further investigations of hypertrophied myocardium are needed at the cellular or molecular level.