Randomised controlled feasibility trial of retroperitoneal vs transperitoneal robot‐assisted partial nephrectomy: the ROPARN study

To assess the feasibility of trial recruitment and confirm that retroperitoneal robotic partial nephrectomy (RRPN) has the same oncological efficacy as transperitoneal robotic partial nephrectomy (TRPN), with time advantages and less peri-operative morbidity, in a randomised controlled trial (RCT). The study was designed as a single-centre, open-label, feasibility RCT. Patients with suspected localised renal cell carcinoma referred for robotic partial nephrectomy were randomised in a 1:1 ratio to receive either TRPN or RRPN. The primary outcomes were trial feasibility, postoperative mobility and pain perception. Secondary outcomes were intra-operative times, assessment of complications, and comparison of positive surgical margin (PSM) rates. The data on all randomised patients who underwent surgery were analysed descriptively. Sixty-one patients underwent TRPN or RRPN (31 vs 30). Postoperative mobility within 24 h after surgery (RRPN: 77 vs TRPN: 71%; P = 0.613), median postoperative pain, assessed using a numeric rating scale (RRPN: 1.5 vs TRPN: 1.8; P = 0.509), and full bowel canalisation within 3 days (RRPN: 100% vs TRPN: 90%; P = 0.315) were more favourable in the RRPN group, but the difference was not statistically significant. In comparison to TRPN, RRPN was associated with shorter operating time (81 vs 105 min; P = 0.005), shorter time on the console (49 vs 73 min; P < 0.001) and shorter time from console to renal artery preparation (7.5 vs 18 min; P < 0.001). TRPN required a shorter time from skin incision to console (16 vs 12 min; P = 0.001). There was no statistically significant difference in tumour complexity, ischaemia time, PSM rate, blood loss or complications between the two groups. We present the first data from an RCT comparing RRPN with TRPN. RRPN showed significant time benefits while being a safe alternative to TRPN, with a similar PSM rate. There was less postoperative morbidity in the RRPN group, although this was not statistically significant. These results underline that dorsolateral renal tumours should be preferably resected by RRPN. Further multicentre RCTs are necessary to confirm these results.