Immediate and long-term results of mitral prosthetic replacement using a right thoracotomy beating heart technique

OBJECTIVE: Repeat median sternotomy is a potentially dangerous technique providing variable but mainly poor access to the mitral valve. Right thoracotomy is an alternative route previously used to access the mitral valve in the early years of cardiac surgery that offers the advantage of a fresh surgical field in the context of redo surgery. We have reviewed our experience with mitral prosthetic replacement undertaken via a right thoracotomy in order to determine the immediate and long-term results obtained with this approach. METHODS: The operation was carried out on a beating heart using normothermic bypass without cross-clamping the aorta. Arterial inflow was achieved via the femoral artery or ascending aorta and venous drainage with bi-caval cannulae. Pre-, intra- and postoperative data were documented from case note review. Long-term follow-up was established from the UK Heart Valve Registry, referring Cardiologist, direct patient contact and the Scottish Registry for births and deaths. Statistical analysis was undertaken using a desktop computer package. RESULTS: One hundred and twenty-five patients (mean age 63 years) underwent mitral prosthetic replacement by this technique. One hundred and eleven patients (86%) were in NYHA grades III or IV preoperatively. Twenty-two patients (16.6%) had also undergone previous CABG. Thirty-five patients (28%) had undergone two or more sternotomies. Mean bypass time was 83.6 min (SD 43.1). Postoperatively, mean duration of ventilation was 44 h; mean ITU stay was 4 days (SD 5.3) and mean inpatient total stay was 12 days. Thirty-six patients (28.8%) required inotropic support postoperatively. Complication rates were low: pleuro-pulmonary, 30 patients (24%), re-operation for bleeding, four patients (3.2%) and CVA, two patients (1.6%). Eight patients (6.4%) died within 30 days. Ten-year survival figures (Kaplan-Meier) were: 47% for all causes of mortality and 82.9% when only valve related causes of death were considered. Most of the patients (97.5%) had not required re-operation at 10 years. CONCLUSION: Mitral prosthetic replacement via a right thoracotomy on beating heart under normothermic bypass offers a safe alternative to redo median sternotomy in this high-risk group. Operative access is facilitated and procedural time reduced. Complication rates are low and perioperative mortality is lower than that generally reported with conventional surgery.