Defining the Tipping Point in Surgical Performance for Laparoscopic Donor Nephrectomy Among Transplant Surgery Fellows: A Risk-Adjusted Cumulative Summation Learning Curve Analysis

The United Network for Organ Sharing recommends that fellowship-trained surgeons participate in 15 laparoscopic donor nephrectomy (LDN) procedures to be considered proficient. The American Society of Transplant Surgeons (ASTS) mandates 12 LDNs during an abdominal transplant surgery fellowship. We performed a retrospective intraoperative case analysis to create a risk-adjusted cumulative summation (RACUSUM) model to assess the learning curve of novice transplant surgery fellows (TSFs). Between January 2000 and December 2014, 30 novice TSFs participated in the organ procurement rotation of our ASTS-approved abdominal transplant surgery fellowship. Measures of surgical performance included intraoperative time, estimated blood loss, and incidence of intraoperative complications. The performance of senior TSFs was used to benchmark novice TSF performance. Scores were tabulated in a learning curve model, adjusting for case complexity and prior TSF case volume. Rates of adverse surgical events were significantly higher for novice TSFs than for senior TSFs. In univariable analysis, multiple renal arteries, high BMI, prior abdominal surgery, male donor, and nephrolithiasis were correlated with higher incidence of adverse surgical events. Based on the RACUSUM model, high intraoperative time is mitigated after 28 procedures, incidence of intraoperative complications tends to diminish after 24 procedures, and improvement in estimated blood loss did not remain consistent. TSFs exhibit a tipping point in LDN performance by 24–28 cases and proficiency by 35–38 cases.