The learning curve for pure retroperitoneoscopic donor nephrectomy by using cumulative sum analysis

Abstract

Introduction: This study aimed to identify a precise learning curve for pure retroperitoneoscopic donor nephrectomy (RDN).

Methods: Data from 172 consecutive kidney donors who underwent pure RDN between January 2010 and July 2019 were prospectively collected and evaluated. Cumulative sum (CUSUM) analysis was used for testing the operation time. Changepoints were determined by using the r program and BINSEG method. The cohort was divided into three groups - group 1: competence, including the first 10 cases; group 2: 11-48 cases as proficiency; and group 3: the subsequent 124 cases as expert level. Continuous variables were evaluated using one-way ANOVA, and categorical data were evaluated using the Chi-squared test.

Results: Right RDN was performed in 39 (22.7%) donors. The eighth patient was converted to open surgery due to vena cava injury and excluded from the CUSUM analysis. Depending on experience in pure RDN, a significant decrease was detected in operative time (p<0.001), warm ischemia time (p=0.006), and blood loss (p<0.001). Recipient complications and graft function were found to be statistically comparable.

Conclusions: In our study, the attainment of expertise in pure RDN was observed after performing 50 cases. The transperitoneal technique, which is a feasible alternative, is far more widely used than pure RDN. We believe that understanding the learning curve associated with pure RDN could facilitate the adoption of this approach as a viable alternative to the transperitoneal approach.

Figure 1

Changepoints were determined by using the binseg method.

Figure 2

The plot of cumulative sum analysis (CUSUM) of operation time against the case number.