Cumulative Sum Analysis of the Learning Curve for Modified Retroperitoneoscopic Living-Donor Nephrectomy

Abstract

Objectives: To introduce our modified retroperitoneoscopic living-donor nephrectomy (RPLDN) techniques and estimate the learning curve. Methods: We retrospectively evaluated 121 consecutive donors who underwent modified RPLDN performed by a single surgeon. While the surgeon controlled the renal vessels, one hand was inserted through an abdominal incision for assistance. The kidney was manually retrieved through the abdominal incision. The learning curve was evaluated using the cumulative sum (CUSUM) method, which was a graphical method showing changes in individual surgical performance. Results: The mean operating time and warm ischemic time (WIT) were 129.4 min and 154.5 s, respectively. The mean estimated blood loss (EBL) was 44.4 mL. Regarding intraoperative complications, no open conversions or blood transfusions were required. The CUSUM learning curve included the following 3 unique phases: phase 1 (the initial 32 cases), representing the initial learning curve; phase 2 (the middle 38 cases), representing expert competence; and phase 3 (the final 51 cases), representing mastery. Conclusions: Our modified method has the advantages of a short operating time, an optimized WIT, a low EBL, and acceptable complication rates. The surgeon completed the initial learning phase of RPLDN after 32 cases and could effectively perform RPLDN after 70 cases.