Trifecta Outcomes to Assess Learning Curve of Robotic Partial Nephrectomy

Background and Objectives: The learning curve for achieving desirable perioperative outcomes in robot-assisted partial nephrectomy (RAPN) has not been well studied.Information is available regarding "trifecta" outcomes of no complications, no positive margins, warm ischemia time (WIT) of Յ25 minutes, and a Յ15% decrease in postoperative glomerular filtration rate (GFR).This study was conducted to assess the impact of the learning curve on surgical outcomes in patients undergoing RAPN.Methods: We reviewed 131 consecutive patients who underwent RAPN by a single, fellowship-trained surgeon from October 2007 through June 2015.Patients were divided into 4 subgroups, and mean perioperative values were compared.The learning curve was evaluated as the time it took the surgeon to attain a trifecta outcome.Results: Means for the RENAL Nephrometry Score, procedure length, WIT, and estimated blood loss (EBL) were 5.3 Ϯ 1.2, 172.1 Ϯ 43.5 minutes, 22.7 Ϯ 7.0 minutes, and 267.2 Ϯ 341.8 mL, respectively.Significance was noted for differences in WIT (P ϭ .50),postoperative creatinine (P ϭ .006),postoperative estimated (e)GFR (P ϭ .40),and percentage change in creatinine (P ϭ .023).The learning curve for achieving positive outcomes was noted in Ͼ61-90 cases after 66 -80 months of performing minimally invasive partial nephrectomy surgeries at a rate of 20 cases per year.Conclusion: RAPN is a safe, feasible procedure with slightly better surgical outcomes than laparoscopic partial nephrectomy (LPN).In the hands of an experienced surgeon, the learning curve for achieving trifecta outcomes can involve a significant number of cases over several years.