Impact of learning curve on the perioperative outcomes following robot-assisted partial nephrectomy for renal tumors.

Introduction: Robot-assisted partial nephrectomy (RAPN) is an established, minimally invasive technique to treat patients with renal masses. The aim of this study was to assess the learning curve (LC) of RAPN, evaluate its impact on perioperative outcomes following RAPN and to study the role of surgeon experience in achieving "trifecta" outcomes following RAPN.

Methods: We prospectively analyzed the clinical and pathological outcomes of 108 consecutive patients who underwent RAPN for renal tumors from January 2012 to December 2016 by a laparoscopy trained surgeon with no prior robotic experience. We used warm ischemia time (WIT) <20 min, operative time <120 min, and blood loss <100 ml as endpoints for plotting the LCs. Trifecta was analyzed in relation to our LC.

Results: Surgeon experience was found to correlate with WIT, operative time, and blood loss. Overall 18.5% of patients developed complications. Complication rate reduced with increasing surgeon experience. LC was 44 cases for WIT ≤20 min, 44 cases for operative time <120 min, and 54 cases for blood loss <100 ml. Trifecta outcome was achieved in 67.6% patients overall and was found to correlate with increasing surgeon experience. Improvement in trifecta outcomes continued to occur beyond the LC.

Conclusions: RAPN is a viable option for nephron-sparing surgery in patients with renal carcinoma. For a surgeon trained in laparoscopy, acceptable perioperative outcomes following RAPN can be achieved after an LC of about 44 cases. Increasing surgeon experience was associated with improved "trifecta" achievement following RAPN.