Learning curve and perioperative outcomes of robot-assisted radical prostatectomy in 200 initial Japanese cases by a single surgeon.

Purpose: The aim of the present study was to investigate the learning curve and perioperative outcomes in 200 consecutive patients with prostate cancer who underwent robot-assisted radical prostatectomy (RARP). Patients and Methods: Between August 2006 and August 2011, 200 patients with prostate cancer underwent RARP and were enrolled in this study. We prospectively collected the demographic data and analyzed the pathologic and functional outcomes. The operative outcomes analyzed were total operative time, estimated blood loss (EBL), positive surgical margin (PSM), incontinence, and perioperative complications. We also evaluated the relationship between the surgeon's experience and operative variables. Results: The sloping learning curve for this surgeon showed that total operative time was strongly correlated with the accumulation of experience for the initial 25 cases (|r(s)|=0.71, P<0.001). The average EBL was not strongly correlated with additional experience (|r(s)|<0.7). The PSM rate for the first 50 cases was significantly higher than that of the next 150 cases (34.8% vs 19.4%, P=0.035). The complication rate among the first 50 patients was significantly higher than that among the remaining 150 patients (32% vs 12.7%, P=0.002). The incontinence rate at 12 months was significantly higher for the first 100 cases compared with that for the next 100 cases (9.0% vs 1.0%, P=0.009). For the surgeon to optimize total operative time, PSM rate, complication rate, and incontinence rate, slope learning curves of 25, 50, 50, and 100 cases were needed. Conclusions: The functional and pathologic results of this minimally invasive procedure seemed to be promising. Distinct learning curves were observed with respect to operative time, PSM, complication rate, and incontinence rate. Exposure to 100 surgeries would be necessary for a surgeon to adequately master the required skills.