Randomized Controlled Feasibility Trial of Robot-assisted Versus Conventional Open Partial Nephrectomy: The ROBOCOP II Study

BACKGROUND

There is no evidence from randomized controlled trials (RCTs) comparing robot-assisted partial nephrectomy (RAPN) and open partial nephrectomy (OPN).

OBJECTIVE

To assess the feasibility of trial recruitment and to compare surgical outcomes between RAPN and OPN.

DESIGN, SETTING, AND PARTICIPANTS

ROBOCOP II was designed as single-center, open-label, feasibility RCT. Patients with suspected localized renal cell carcinoma referred for PN were randomized at a 1:1 ratio to either RAPN or OPN.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was the feasibility of recruitment, assessed as the accrual rate. Secondary outcomes included perioperative and postoperative data. Data were analyzed descriptively in a modified intention-to-treat population consisting of randomized patients who underwent surgery.

RESULTS AND LIMITATIONS

A total of 50 patients underwent RAPN or OPN (accrual rate 65%). In comparison to OPN, RAPN had lower blood loss (OPN 361 ml, standard deviation [SD] 238; RAPN 149 ml, SD 122; difference 212 ml, 95% confidence interval [CI] 105-320; p < 0.001), less need for opioids (OPN 46%; RAPN 16%; difference 30%, 95% CI 5-54; p = 0.024), and fewer complications according to the mean Comprehensive Complication Index (OPN 14, SD 16; RAPN 5, SD 15; difference 9, 95% CI 0-18; p = 0.008). OPN has a shorter operative time (OPN 112 min, SD 29; RAPN 130 min, SD 32; difference -18 min, 95% CI -35 to -1; p = 0.046) and warm ischemia time (OPN 8.7 min, SD 7.1; RAPN 15.4 min, SD 7.0; difference 6.7 min, 95% CI -10.7 to -2.7; p = 0.001). There were no differences between RAPN and OPN regarding postoperative kidney function.

CONCLUSIONS

This first RCT comparing OPN and RAPN met the primary outcome of the feasibility of recruitment; however, the window for future RCTs is closing. Each approach has advantages over the other, and both remain safe and effective options.

PATIENT SUMMARY

For patients with a kidney tumor, open surgery and robot-assisted keyhole surgery are both feasible and safe approaches for partial removal of the affected kidney. Each approach has known advantages. Long-term follow-up will explore differences in quality of life and cancer control outcomes.

ROBOCOP II (ROBOtic assisted versus conventional open partial nephrectomy) randomised, controlled feasibility trial: clinical trial protocol

INTRODUCTION

Randomised controlled trials comparing robotic-assisted partial nephrectomy (RAPN) and open PN (OPN) are lacking. Therefore, we aim to report the study protocol and a trial update for a randomised controlled feasibility trial comparing RAPN versus OPN for renal neoplasms.

METHODS AND ANALYSIS

The ROBOtic assisted versus conventional Open Partial nephrectomy II trial is designed as a single-centre, randomised, open-label, feasibility trial. Participation will be offered to patients with renal neoplasms and deemed feasible for both, OPN and RAPN. We aim to enrol 50 patients within 15 months using a 1:1 allocation ratio. The primary endpoint of the trial is feasibility of recruitment and will be successful if one third of eligible patients agree to participate. Secondary endpoints include perioperative results, health-related quality of life, inflammatory response as well as surgical ergonomics of the operating team. If the primary outcome, feasibility of recruitment, is successful, the secondary results of the trial will be used for planning a confirmative phase III trial.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the local institutional review board (Ethik-Kommission II at Heidelberg University: 2020-542N). Results will be made publicly available in peer-reviewed scientific journals and presented at appropriate congresses and social media.

TRIAL REGISTRATION NUMBER

NCT04534998.

Robotic-Assisted Versus Conventional Open Partial Nephrectomy (Robocop): A Propensity Score-Matched Analysis of 249 Patients

OBJECTIVES

The objective of this study was to compare open partial nephrectomy (OPN) and robotic-assisted PN (RAPN) based on a propensity score-matched sample and to test the Comprehensive Complication Index (CCI) as an end point for complications.

METHODS

Patients undergoing PN from 2010 to 2018 at a university care center were included. OPN and RAPN cases were matched in a 2:1 ratio using propensity score-matching with age, gender, BMI, RENAL score, and tumor size as confounders. The primary end point was complications measured with the CCI as continuous score (0-100, 100 indicating death).

RESULTS

Data of 570 patients were available. After matching, both cohorts (OPN = 166; RAPN = 83) showed no baseline differences. For the primary end point, CCI, RAPN was superior (RAPN 2.6 ± 7.9 vs. OPN 8.7 ± 13.9; p < 0.001). Additionally, RAPN was superior for length of stay (RAPN 6.5 ± 4.0 vs. OPN 7.4 ± 3.5 days; p < 0.001), hemoglobin drop (RAPN 2.8 ± 1.4 vs. OPN 3.8 ± 1.6 g/dL; p < 0.001), and drop of glomerular filtration rate (RAPN 11.4 ± 14.2 vs. OPN 19.5 ± 14.3 mL/min; p < 0.001). OPN had shorter operating times (RAPN 157 ± 43 vs. OPN 143 ± 45 min; p = 0.014) and less ischemia (RAPN 13% vs. OPN 28%; p = 0.016).

CONCLUSIONS

RAPN provides superior short-term results regarding overall complications without compromising renal function for small and less complex tumors. However, OPN remains an important option for more complex and larger tumors.