Re-do Cases and Histidine Buffered Cardioplegia / 日本心臓血管外科学会雑誌

ABSTRACT

Re-do open cardiac surgery may sometimes require complete ablation around the pericardium for the 2 major reasons of attaining better myocardial protection and obtaining effective DC cardioversion. However, this ablation may increase postoperative hemorrhage which may require blood transfusion. Hypothermia is based on the concept of myocardial protection during open heart surgery by suppressing myocardial metabolism, but recently the approach has been changed to maintaining myocardial metabolism with aerobic or anaerobic energy production. We have already reported that histidine-buffered cardioplegia which promote anaerobic glycolysis, provided an excellent functional recovery of myocardium post-ischemia with lower inotropic requirements in a range from 10°C to 37°C of myocardial temperature. Based on our theoretical background and clinical data, we tested the efficacy of this type of cardioplegia in patients receiving multiple surgical procedures with minimum ablation after sternotomy. First case, who had undergone a Bentall procedure for annulo-aortic ectasia 14 years previously had a thrombotic valve and mitral regurgitation. Aortic valve plasty and mitral valve replacement (MVR) was performed. The second case who had undergone MVR 15 years previously had malfunction of the prosthetic valve and underwent re-MVR. The third and fourth cases had ventricular septal defect (VSD) which were closed using Teflon patches. The third case had patch closure during second operation for residual shunt. The fourth case received tricuspid valve replacement (TVR) for tricuspid regurgitation due to a pacemaker lead implanted into the right ventricle through the left subclavian vein. The fifth case received coronary artery bypass surgery in a second operation for restenosis of the graft and progressing atherosclerosis. All hearts started beating spontaneously without DC cardioversion after the aortic unclamp. Ventricular fibrillation occurred in the first case while the patient was weaned from cardiopulmonary bypass and treatment was performed by aortic cross clamp, infusion of the cardioplegia followed by aortic unclamp to start own beat again. Two of 3 patients who were able to donate their own blood preoperatively did not require homologous blood transfusion. Due to advantages such as excellent myocardial protection under hypothermic or normothermic condition, ease of use and relatively lower potassium concentration, histidine-buffered cardioplegia can be an excellent candidate for myocardial protection in re-do cases with less ablation technique.