Fig. 2.

Frequency of Time-Based Metrics Used to Define the Learning Curve in Included Studies. This figure summarizes the number of studies that reported key intraoperative time metrics to assess learning curve progression. Total procedure time and cross-clamp/occlusion time were each reported in 18 studies, cardiopulmonary bypass (CPB) time in 17 studies, and harvest time in 7 studies. These variables represent the most commonly used quantitative indicators of surgical proficiency in robotic cardiac surgery learning curve analyses