The learning curve of minimally invasive aortic valve replacement for aortic valve stenosis

Few clinical studies have been conducted to evaluate the learning curve of minimally invasive aortic valve replacement. The purpose of this study was to retrospectively analyze the learning curve of initial and isolated minimally invasive aortic valve replacement for aortic valve stenosis which performed at our institution.

This study included 126 patients who underwent initial and isolated minimally invasive aortic valve replacement via right infra-axillary mini thoracotomy for aortic valve stenosis. Patients were divided into the first 50 patients [1-50 cases: E group (n = 50)] and the last 76 patients [51-126 cases: L group (n = 76)].

A significantly shorter operative time (239.4 ± 35.2 min vs. 206.5 ± 25.5 min, P < 0.001), cardiopulmonary bypass time (151.1 ± 27.4 min vs. 126.9 ± 20.2 min, P < 0.001) and aortic cross-clamp time (115.2 ± 19.0 min vs. 93.9 ± 14.7 min, P < 0.001) were found in the L group. The learning curves of operative time, cardiopulmonary bypass time, and aortic cross-clamp time plateaued after 40 cases.

Learning curves were observed in surgical processes such as operative time. A total of 40-50 cases are required to achieve a stable operative time. However, patient outcomes were not significantly different between the groups. This study could be helpful in introducing minimally invasive aortic valve replacement and designing training programs.