What Does Minimally Invasive Mitral Valve Surgery Really Mean? Defining Totally Endoscopic Mitral Valve Surgery Through Meta Analysis.

INTRODUCTION: Minimally invasive approaches to mitral valve surgery are being performed with increasing frequency; however, many of these procedures still involve rib spreading and large incisions. The heterogeneity of self-reported "minimally invasive" approaches limits analysis of outcomes. This review aims to formally define totally endoscopic mitral valve surgery (TEMVS) and assess outcomes. MATERIALS AND METHODS: A comprehensive literature search in Pub-Med, Cochrane Library, and EMBASE was used to find studies reporting outcomes on totally endoscopic mitral valve surgery. "Totally endoscopic" was defined as incisions less than 3cm and the avoidance of rib spreading. The primary outcome was 30-day mortality and secondary endpoints included postoperative myocardial infarction (MI), stroke, early reoperation, wound infection, renal failure, and prolonged ventilation. Perioperative patient characteristics were also recorded and analyzed. RESULTS: Thirty-three studies (6031 patients) were included in our meta-analysis. The 30-day mortality rate was 0.33%, p=0.88. The most frequent complications were early reoperation (2.12%, p=0.44) and prolonged ventilation (1.46% p=<0.01). Rates of MI, stroke, and renal failure were each less than 1%. Patient characteristics including age, body mass index (BMI), and ejection fractions were also analyzed. CONCLUSIONS: We propose a formal definition of TEMVS, which is performed through incisions less than 3cm and without rib spreading. Thirty-day mortality and other adverse sequelae of TEMVS are uncommon.