The prospective, randomised, open-label, multicentre OpeRa trial (NCT03849820) aimed to determine whether robotic-assisted partial nephrectomy (RAPN) is superior to open partial nephrectomy (OPN) in reducing 30-day post-operative complications during the treatment of intermediate/high-complexity renal tumours.
Patients and methods
Eligible patients aged ≥18 years had a renal tumour suitable for OPN or RAPN, a RENAL score ≥7, and an estimated glomerular filtration rate ≥50 ml/min/1.73 m2. Patients were randomised from 15 March 2019 to 23 November 2021 in 12 German hospitals and assigned (1 : 1) to undergo RAPN or OPN. Primary endpoint was the 30-day post-operative complication rate [Clavien–Dindo (CD) I-V] in the modified intention-to-treat population. We aimed to recruit 606 patients to detect ≥10% reduction in the primary endpoint for RAPN versus OPN.
Results
A total of 240 patients were randomised to RAPN (n = 123) or OPN (n = 117). Enrolment was stopped prematurely due to slow recruitment. After patient withdrawal post-randomisation, 117 patients underwent RAPN and 90 OPN. The primary endpoint was assessable in 112 and 89 patients, respectively. The 30-day complication rate did not differ between groups: RAPN 41/112 (37%) versus OPN 41/89 (46%) (one-sided: P = 0.088). The difference of −9.5% (95% confidence interval −23.1% to 4.2%) numerically favoured RAPN. The most frequent high-grade complications (CD III-IV) to post-operative day 30 (POD30) were urine leakage [RAPN 4/112 (4%) versus OPN 2/89 (2%)] and post-operative bleeding [2/117 (2%) versus 1/89 (1%)]. Compared with OPN, RAPN patients had longer operative and warm ischaemia times, shorter hospital stay, and reported better recovery, less opioid use, less pain, and improved quality of life (QoL) up to POD30.
Conclusions
There was no statistically significant difference in the 30-day complication rate between RAPN and OPN in this underpowered trial. Few high-grade complications occurred over the whole cohort with intermediate/high-complexity tumours. Despite less intense pain management, patients undergoing RAPN reported less pain and better QoL up to POD30.
The OpeRa trial is the first prospective, randomised, multicentre study to assess the superiority of robotic-assisted partial nephrectomy (RAPN) compared to open partial nephrectomy (OPN) in patients with intermediate- to high-complexity renal tumours. Eligible patients had a R.E.N.A.L. score ≥7 and an estimated glomerular filtration rate (eGFR) ≥50 ml/min/1.73m². Recruitment took place between 2019 and 2021; however, due to slow enrolment, the trial was prematurely stopped after enrolling only 240 patients instead of the planned 606.
A total of 117 patients underwent RAPN and 90 underwent OPN. The 30-day complication rates were similar: 41/112 (37%) for RAPN vs. 41/89 (46%) for OPN (one-sided P=0.088). The most frequent high-grade (Clavien-Dindo III–IV) complications by postoperative day 30 (POD30) were urine leakage (RAPN: 4/112 [4%], OPN: 2/89 [2%]) and postoperative bleeding (RAPN: 2/117 [2%], OPN: 1/89 [1%]).
Compared to OPN, the RAPN group had longer operative and warm ischaemia times but benefited from a shorter hospital stay. Patients also reported better postoperative recovery, less opioid use, reduced pain, and improved quality of life up to POD30.
German urologists should be congratulated for successfully conducting a randomised controlled trial (RCT) in this surgical field. Despite being a negative trial in terms of primary endpoint superiority, valuable insights can still be gained. Notably, although the RAPN arm had fewer overall complications, the rate of high-grade complications (Clavien-Dindo III–IV) was numerically higher in the RAPN group (13/112 [11.6%] vs. 7/89 [7.8%] for OPN). This may reflect the early learning curve of some participating surgeons, as surgeon experience was not documented – and partial nephrectomy is known to have a long learning curve.
Another consideration is that most OPNs were performed via a retroperitoneal approach, while RAPNs were predominantly transperitoneal. This difference could affect bleeding outcomes, as the retroperitoneal space may help compress bleeding vessels. Although ischaemia and operative times were longer in the RAPN group, it had lower estimated blood loss (by approximately 50 ml), shorter hospital stays, and a higher rate of negative surgical margins.
OPN patients required more opioid analgesia, and at one month, RAPN patients experienced less disruption to normal work activities. However, by three months postoperatively, differences in quality of life and pain scores had evened out. Short-term renal function was comparable between the two groups.
Similar findings were observed in the feasibility ROBOCOP II trial, where overall complications were lower in the RAPN arm, yet serious complications requiring re-intervention were more frequent. That study also demonstrated less blood loss and reduced analgesia use with RAPN, while OPN offered shorter operative and ischaemia times.
Conclusion
RAPN appears preferable when minimising blood loss, reducing analgesia needs, and shortening hospital stay are priorities. Conversely, OPN remains a valid option, particularly when shorter ischaemia and operative times are of greater clinical importance. However, due to limited recruitment, the conclusions are not definitive. In addition, complication and re-intervention rates at one-year follow-up would be particularly valuable for a comprehensive cost-analysis.