Step-specific temporal patterns in robot-assisted sacrocolpopexy: an exploratory CUSUM analysis

Background Learning curves for robot-assisted sacrocolpopexy (RSC) are commonly evaluated using total operative or console time, although RSC consists of multiple technically distinct steps. We evaluated step-specific learning patterns using cumulative sum (CUSUM) analysis. Methods We retrospectively analyzed the first 29 consecutive RSC procedures performed by a single surgeon with approximately 100 prior robotic procedures and experience in robotic surgical instruction. Seven procedural steps were timed using prespecified video landmarks. CUSUM analysis and Spearman correlations were used to evaluate temporal efficiency patterns. Early and late phases were compared using the console-time CUSUM peak. Results Median operative and console times were 183 and 139 min, respectively, and both CUSUM curves peaked at case 14. Step-specific CUSUM peaks varied substantially. Hysterectomy, anterior and posterior mesh suturing, and peritoneal closure became significantly shorter with increasing case sequence, whereas bladder dissection showed greater variability and a later CUSUM peak. Despite significant shortening of several individual steps in the late phase, total operative and console times did not differ significantly between phases. Conclusions RSC demonstrated heterogeneous step-specific learning patterns that were not captured by total console time alone. Even for an experienced robotic surgeon, step-specific CUSUM analysis may identify procedure-specific technical bottlenecks and provide an objective framework for proctoring and surgical training.