Learning Curves and Timing of Surgical Trials: Robotic Kidney Transplantation with Regional Hypothermia

Outcomes of surgical procedures can be affected by multiple factors including surgical skill and learning curve (LC). These factors need to be considered for optimal timing of surgical trials. We used the LC cumulative summation (CUSUM) method to describe the number of cases associated with competency of a single surgeon learning the technique of robotic kidney transplantation (RKT).

Thirty-three patients underwent Vattikuti Urology Institute technique of RKT at a center that recently adopted this procedure (study group). Anastomoses times and short-term functional outcomes were compared with an established RKT program (reference group). LCs were evaluated using CUSUM analysis using target values from the reference group.

Mean ± standard deviation for console time, rewarming time (RWT), arterial anastomosis, venous anastomosis, and ureterovesical anastomosis times for the study group was 187 ± 34.6 minutes, 58.03 ± 17.81 minutes, 19.36 ± 5.91 minutes, 21.97 ± 6.78 minutes, and 22.55 ± 4.24 minutes, respectively, significantly longer than reference group (p < 0.001 for all). Mean ± standard deviation for serum creatinine at discharge and 1 month in the study group was 1.43 ± 0.57 mg/dL and 1.23 ± 0.35 mg/dL, respectively, similar to the reference group (p = 0.074 at discharge and p = 0.163 at 1 month). The LC was short, with competence achieved for RWT within 9, proficiency within 16, and mastery within 21 cases. Longer anastomosis times during the LC did not affect graft function.

The LC of RKT is short, with improving skill up to 20-25 cases. The procedure is reproducible by surgeons experienced with open transplant and robotic surgery for other procedures, with comparable outcomes and low complication rates at a new center during adoption.