Mitral valve surgery under perfused ventricular fibrillation with moderate hypothermia.
The safety and myocardial protective effect of perfused ventricular fibrillation (VF) under moderate hypothermia were investigated. Through a midline sternotomy and opening the left atrium from the right side, isolated mitral valve surgery was performed under aortic cross-clamping (ACC) and cardioplegic arrest using Bretschneider HTK solution in 96 patients, and under perfused VF in 20 patients (VF Group). Patient characteristics, clinical outcomes, and perioperative variables were compared. A satisfactory surgical view was obtained in all VF Group patients. Patient characteristics in the 2 groups were similar, and both groups had comparable results for mortality and morbidity, operation time, cardiopulmonary bypass time, peak levels of creatine kinase (CK) and its myocardial fraction, hours of mechanical ventilation, intensive care unit stay, and postoperative left ventricular ejection fraction. Even in VF Group patients with preoperative critical hemodynamic compromise, inotropes could be discontinued within 3 days. Thus, no detrimental effect of perfused VF was observed. On the other hand, in patients who underwent ACC and cardioplegic arrest of 120min or longer, peak levels of CK and its myocardial fraction were significantly higher than those of the rest of C group patients and VF Group patients. Perfused VF under moderate hypothermia can be a good alternative myocardial protection strategy during mitral valve surgery, particularly in patients in whom ACC is unsuitable or the duration of ACC is expected to be long.