Retroperitoneal vs. transperitoneal robotic partial nephrectomy: a multicenter propensity-score matching analysis (PADORA Study - UroCCR n° 68).

Background: Robot-assisted partial nephrectomy can be performed through either a transperitoneal or retroperitoneal approach. This study aimed to compare the rate of trifecta achievement between retroperitoneal (RRPN) and transperitoneal (TRPN) robot-assisted partial nephrectomy using a large multicenter prospectively-maintained database and propensity-score matching analysis.
Methods: This study was launched by the French Kidney Cancer Research Network, under the UroCCR Project (NCT03293563). Patients who underwent TRPN or RRPN by experienced surgeons in 15 participating centers were included. Data on demographic and clinical parameters, tumor characteristics, renal function, and surgical parameters were collected. The primary outcome was the rate of trifecta achievement, which was defined as a warm ischemia time of less than 25 minutes, negative surgical margins, and no major complications. Secondary outcomes included operative time, hospital length-of-stay, blood loss, postoperative complications, postoperative renal function, and each trifecta item taken alone. Subgroup analysis was done according to tumor location.
Results: A total of 2879 patients (2581 TRPN vs. 298 RRPN) were included in the study. Before matching, trifecta was achieved in 73.0% of the patients in the TRPN group compared to 77.5% in the RRPN group (P=0.094). After matching 157 patients who underwent TRPN to 157 patients who underwent RRPN, the trifecta rate was 82.8% in the TRPN group vs. 84.0% in the RRPN group (P=0.065). The RRPN group showed shorter operative time (123 vs. 171 min; P<0.001) and less blood loss (161 vs. 293 mL; P<0.001). RRPN showed a higher trifecta achievement for posterior tumors than TRPN (71% vs. 81%; P=0.017).
Conclusions: RRPN is a viable alternative to the transperitoneal approach, particularly for posterior renal tumors, and is a safe and effective option for partial nephrectomy.