Short-term outcomes of minimally invasive mitral valve repair: a propensity-matched comparison

We aimed to investigate the effect of minimally invasive mitral valve repair on early pulmonary function and haemodynamics, as well as its short-term efficacy.

From March 2012 to July 2015, 78 cases of minimally invasive mitral valve repair and 89 cases of conventional mitral valve repair were included in this study, with 67 well-matched pairs of patients identified by a propensity score matching, who were divided into the conventional sternotomy group and the right minithoracotomy group (the RT group).

The in-hospital mortality was similar between the 2 groups (3.0% vs 1.5%, P = 1.000). Both cross-clamp time and bypass time were higher in the RT group (P < 0.001), whereas drainage amount, blood transfusion and length of intensive care unit stay were higher in the conventional sternotomy group (P < 0.001). There was not much discrepancy in pulmonary function between the 2 groups, except that partial pressure of O2 in arterial blood (PaO2)/fraction of inspired oxygen (FiO2) in the RT group was significantly lower than that in the conventional sternotomy group 0, 4 and 8 h after surgery (P < 0.05), whereas the extravascular lung water index (ELWI), pulmonary vascular permeability index (PVPI) and alveolar-arterial PO2 difference (PA-aO2) of the RT group was higher (P < 0.05). We found no disparity in haemodynamics (P > 0.05), incidence of complications (P > 0.05) and short-term recurrence between the 2 groups (P = 0.7697).

When compared with the median sternotomy approach, the RT approach shows comparable results in short-term efficacy and safety. On relatively increasing cardiopulmonary bypass time and operation time, the RT approach shortens the patient's intensive care unit stay and reduces the need for blood transfusion. Pulmonary function may be affected shortly post-surgery in the RT approach, with insignificant difference in haemodynamics.