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

Abstract

BackgroundThere is no evidence from randomized controlled trials (RCTs) comparing robot-assisted partial nephrectomy (RAPN) and open partial nephrectomy (OPN). ObjectiveTo assess the feasibility of trial recruitment and to compare surgical outcomes between RAPN and OPN. Design, setting, and participantsROBOCOP 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 analysisThe 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 limitationsA 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. ConclusionsThis 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 summaryFor 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.