Six-year single-centre experience in minimally invasive mitral valve repair – impact of the team learning curve on in-hospital clinical outcome

Introduction: Minimally invasive mitral repair is less traumatic and more acceptable for the patient than traditional surgery. However, it is a challenging procedure that requires effort from all the personnel involved. Aim: To investigate the results of the minimally invasive mitral valve repair learning curve at the institution. Material and methods: The indication for the surgery was severe mitral regurgitation. Patients with other valvular insufficiency, body mass index (BMI) > 30 kg/m 2 , ejection fraction (EF) < 45%, aortic dilatation, reoperation, pleural adhesions, coronary artery disease requiring invasive treatment, and pregnant women were disqualified. The patients were assigned to one of three groups regarding their surgery date -group 1 (2012-2013), group 2 (2014-2015) and group 3 (2016-2017). The primary endpoints were death, myocardial infarction, stroke, an reoperation for mitral dysfunction. The investigation was performed to determine preoperative parameters (EuroSCORE, age, sex, BMI, arrhythmias, EF), intraoperative parameters (procedure, cross-clamp, extracorporeal circulation), and postoperative parameters (chest revision, transfusion, drainage, ventilation time, pleurocentesis, hospitalization time). Results: There were 173 patients in total. One patient from group 1 (0.6% overall) died. No myocardial infarction or stroke was observed in any of the three groups. Chest revision count (5 vs. 1 vs. 1; p = 0.0004), total drainage (797.20 vs. 517.92 vs. 449.69; p = 0.0018) and hospitalization time (7.89 vs. 7.18 vs. 6.73; p = 0.0005) were significantly different among the groups. The ventilation time, transfusion number and pleurocentesis count did not differ significantly. Conclusions: The procedure is safe and ensures optimal perioperative results. The number of complications is low and acceptable.