Learning Curve in Laparoscopic Pancreaticoduodenectomy: Using Risk-Adjusted Cumulative Summation Methods

Laparoscopic pancreaticoduodenectomy (LPD) is one of the most technically challenging operations of minimally invasive surgery. We aimed to analyze the learning curve of a single surgeon who conducted 115 LPDs at a single center. From August 2015 to August 2020, 115 patients underwent LPD. Patient characteristics and perioperative variables were retrospectively collected and analyzed. Cumulative summation (CUSUM) and risk-adjusted cumulative summation (RA-CUSUM) analyses were used to evaluate the LPD learning curve. All variables were compared after dividing the learning curve phases. After 74 cases, operative time improved based on the CUSUM analysis of the operation time. From the RA-CUSUM analysis, three distinct phases of the learning curve were identified (phase I: 1-42 cases, phase II: 43-73 cases, and phase III: 74-115 cases). The mean operative time was significantly lower in phase III compared with that in phases I and II (348.5 minutes versus 444.6 minutes and 439.9 minutes, P < .001 and P < .001, respectively). The rate of estimated blood loss >500 mL was significantly decreased among the three phases (P = .017). The conversion rate significantly decreased from 11.9% in phase I to 6.5% in phase II to 0% in phase III (P = .023). The rates of overall complication (Clavien-Dindo >IIIA), postoperative pancreatic fistula, and postpancreatectomy hemorrhage were significantly decreased as phases progressed. Postoperative hospital stay, 30-day mortality, and 30-day readmission did not significantly differ among phases. According to learning curve analyses, the LPD failure rate plateaued after 42 cases and stabilized after 73 cases.