ObjectiveTo compare early outcomes of the minimally invasive mitral valve surgery (MIMVS) through right anterolateral mini-thoracotomy (ALMT) with conventional mitral valve surgery (MVS), and evaluate feasibility and safety of MIMVS. MethodsFrom January 2011 to December 2013, 120 patients undergoing elective MVS in Nanjing First Hospital were prospectively enrolled in this study. There were 72 male and 48 female patients with their age of 22-71 (42.4±11.0) years. Using a random number table, all the patients were randomly divided into a portaccess MIMVS group (MIMVS group, n=60) and a conventional MVS group (conventional group, n=60). MIMVS group patients received port-access cardiopulmonary bypass (CPB) establishment via femoral artery, femoral vein and right internal jugular vein cannulation through right ALMT 5-6 cm in length. Special MIMVS operative instruments were used for mitral valve repair or replacement. Conventional group patients received mitral valve repair or replacement under conventional CPB through median sternotomy. Perioperative clinical data, morbidity and mortality were compared between the 2 groups. ResultsThere was no death in-hospital or shortly after discharge in this study. CPB time (98.0±26.0 minutes vs. 63.0±21.0 minutes) and aortic cross-clamping time (68.0±9.0 minutes vs.37.0±6.0 minutes) of MIMVS group were significantly longer than those of conventional group (P<0.05). Postoperative mechanical ventilation time (6.0±3.9 hours vs. 11.2±5.6 hours), length of ICU stay (18.5±3.0 hours vs. 28.6±9.5 hours) and postoperative hospital stay (8.0±2.0 days vs. 13.5±2.5 days) of MIMVS group were significantly shorter than those of conventional group (P<0.05). Chest drainage volume within postoperative 12 hours (110.0±30.0 ml vs. 385.0±95.0 ml) and the percentage of patients receiving blood transfusion (25.0% vs. 58.3%) of MIMVS group were significantly lower than those of conventional group (P<0.05). Patients were followed up for 1-24 months, and the follow-up rate was 94.2%. There was no statistical difference in postoperative morbidity or mortality between the 2 groups (P>0.05). ConclusionMIMVS through right ALMT is a safe and feasible procedure for surgical treatment of mitral valve diseases. MIMVS can achieve similar clinical outcomes as conventional MVS, but can significantly shorten postoperative ICU stay and hospital stay, reduce blood transfusion, and is a good alternative to conventional MVS.