The Learning Curve for Retroperitoneoscopic Donor Nephrectomy
Condition: Transplant;Failure,Kidney
MeSH terms: Renal Insufficiency
Study type: Observational

Summary: 
      Purpose: The aim of the study is 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. CUSUM (cumulative sum) 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 refers to 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-square test
    

Detailed description: 
      The prospectively collected data of 172 consecutive kidney donors undergoing pure RDN for
      transplantation at Ondokuz Mayıs University from January 2010 to July 2019 were evaluated
      retrospectively. Tc-99m mercaptoacetyltriglycine (MAG3) renal scintigraphy was performed to
      evaluate for split renal function. Three-dimensional computed tomography was performed to
      evaluate kidney anatomy and vasculature. The final decision for the laterality of surgery was
      based on the conviction that the better kidney remains with the donor. If both kidneys have
      equal functional characteristics, the left kidney or the kidney with simpler vascular anatomy
      was procured based on the transplantation medical review board's decision. The demographic
      data including age, gender, body mass index (BMI), preoperative renal function, number of
      renal arteries and veins were recorded. Perioperative variables such as operation time (OT),
      warm ischemia time (WIT), estimated blood loss (EBL), perioperative and postoperative
      complications were also recorded. Furthermore, the outcomes of renal recipients including
      graft function, complications and follow-up were recorded as well. In our previously
      published article provides a thorough description of the surgical procedure and details for
      the right and left sides of pure RDN. All RNDs were performed by a single surgeon with
      experience in retroperitoneoscopic laparoscopic surgery and kidney transplantation.

      Learning curve analysis The CUSUM analysis and BinSeg (Binary Segmentation) method Although
      the CUSUM analysis was first built to evaluate industrial sector performance, it has been
      adopted in medicine to interpret many surgical techniques learning curve. In a timeline, it
      calculates the sum of the existing differences between individual operation times and the
      mean of all operation times. Its main use of in medicine is that calculates the sum of the
      existing differences between individual operation times and the mean of all operation times
      in a timeline. The next step is to identify significant change points to determine the
      development. The "changepoint" package was used in the R program to determine the change
      points. The changepoints were determined according to the mean variation. BinSeg methods were
      used to identify two exchange points. Penalty methods were not used to determine surgical
      time change points. The "Normal" method was used as the test statistic for the surgical time.
      According to the learning curve analysis methods that are mentioned above, the whole cohort
      was divided into three groups. Inspired by the Dreyfus model of skill acquisition in the
      naming of the groups. Thus, group 1 represents competence, group 2 is proficiency level, and
      group 3 is the expert level.
    

Observational model: Cohort
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        The prospectively collected data of 172 consecutive kidney donors undergoing pure
        retroperitoneoscopic donor nephrectomy for renal transplantation at Ondokuz Mayıs
        University, Faculty of Medicine, Department of Urology from January 2010 to July 2019 were
        evaluated retrospectively.
      
Keywords: retroperitoneoscopy; donor nephrectomy; Learning curve; CUSUM analysis