Does full sternotomy have more significant impact than the cardiopulmonary bypass time in patients of mitral valve surgery?

Over the past decade, minimally invasive mitral valve surgery (MIMVS) has grown in popularity. Less invasive approaches to mitral valve surgery are increasingly used for improved cosmesis. We sought to compare these minimally invasive approaches fairly with conventional full sternotomy approaches by using propensity-matching methods. From January 2011 to January 2017, a total of 1120 isolated mitral valve operations were performed at our institution. Data were retrospectively collected on all patients, and a logistic regression model was created to predict selection to a minimally invasive versus conventional sternotomy approach. Propensity scores were then generated based on the regression model and matched pairs created using 1:1 nearest neighbor matching. There were 165 matched pairs in the analysis (sternotomy, n = 165;MIMVS, n = 165). Clinical outcomes included bypass and cross-clamp time, length of hospitalization, morbidity, and mortality. Patient details and follow-up outcomes were compared using multivariate, and Kaplan-Meier analyses. The minimally invasive approach led to slightly longer cardiopulmonary bypass time (99 ± 25 vs 88 ± 17 min, p