Trifecta outcomes to assess learning curve of robotic partial nephrectomy

Abstract

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 ≤25 minutes, and a ≤15% 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 ± 1.2, 172.1 ± 43.5 minutes, 22.7 ± 7.0 minutes, and 267.2 ± 341.8 mL, respectively. Significance was noted for differences in WIT (P =. 50), postoperative creatinine (P =. 006), postoperative estimated (e)GFR (P =. 40), and percentage change in creatinine (P =. 023). The learning curve for achieving positive outcomes was noted in >61-90 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.