Mitral valve replacement via minimally invasive totally thoracoscopic surgery versus traditional median sternotomy: a propensity score matched comparative study.

backgroundTo compare surgical outcomes after mitral valve replacement via either minimally invasive thoracoscopic (MIs) or traditional median sternotomy (MS) surgery and determine the short- and mid-term clinical outcomes of the MI approach.

methodsAll patients who received either MIs (n=405) or MS (n=691) mitral valve replacement surgery at the Guangdong Cardiovascular Institute between January 2012 and July 2015 were analyzed for outcome differences due to surgical approach using propensity score matching. The best 202 matches from the MI group and the MS group were analyzed. The clinical data of the two groups were collected, including preoperative cardiac function, operative data, postoperative complications, and follow-up.

resultsA final total of 404 patients were included in this study after propensity score matching; the MIs group and the MS group each contained 202 patients. The two groups were similar in age, weight, pathological changes, and surgical approach. Compared with the MS group, the MIs group had a longer cardiopulmonary bypass time (P<0.001), aortic cross-clamping time (P<0.001), and total procedure time (P<0.001). There were no significant differences between the groups regarding in-hospital mortality, stroke, pneumonia, acute renal failure, arrhythmia, and chylothorax. The MS group had significantly more patients with poor wound healing than the MIs group (P=0.004). The MI group had a lower rate of transfusion (P=0.037), shorter ventilation time (P=0.041), shorter ICU stay (P=0.033), reduced chest tube drainage and length of chest tube stay (P<0.001), and shorter hospital stay (P<0.001). There was no significant difference between the groups in hospital re-admission for bleeding, but the total hospitalization cost was higher in the MIs group (P=0.002). The mean follow-up was 26.59±12.33 months, the 1-year postoperative survival rate was 98.86%, and the overall survival rate was 97.44%. Compared with the MS group, the MIs group recovered earlier (P<0.05), and returned to work or study earlier (P<0.05). More patients in the MIs group were satisfied with the wound (P<0.001). The MS group had a higher incidence of postoperative osteomyelitis than the MIs group (P=0.028). There were no significant differences between groups in rates of mortality, stroke, pacemaker, reoperation, or 36-item Short Form Health Survey score.

conclusionsCompared with the MS approach, the MIs method of mitral valve replacement has longer cardiopulmonary bypass time and aortic cross-clamp time; however, it does not increase the risk of mortality and complications. Furthermore, MIs causes less trauma, fewer transfusions, less wound infection, faster recovery, faster return to work or study, and greater satisfaction with the incision in the mid-term. MI cardiac surgery is safe, effective, and feasible.