Off-clamp Versus On-clamp Robot-assisted Partial Nephrectomy: A Systematic Review and Quantitative Synthesis by the European Association of Urology Young Academic Urologists Renal Cancer Study Group

CONTEXT: The superiority of off-clamp robot-assisted partial nephrectomy (RAPN) over the on-clamp technique has recently been questioned by randomized controlled trials comparing the two techniques. OBJECTIVE: To systematically review the recent literature and perform a quantitative synthesis of data on the comparison of off-clamp versus off-clamp hilar control during RAPN. EVIDENCE ACQUISITION: A systematic search was performed in the PubMed, Embase, Web of Science, and Scopus databases for studies comparing off-clamp versus on-clamp RAPN in terms of perioperative and functional outcomes. The study protocol was registered in the PROSPERO database (CRD42023413160). Only prospective randomized controlled trials and retrospective matched observational studies were included. The primary outcome of the study was the percentage decrease in the estimated glomerular filtration rate (eGFR). EVIDENCE SYNTHESIS: A total of 11 studies were included involving a total of 2483 patients (944 patients in the off-clamp and 1539 patients in the on-clamp group). There was no difference between the two groups in the percentage decline in eGFR (mean difference [MD] 0.04%, 95% confidence interval [CI] −3.7% to 3.86%; p = 0.98). There were so significant differences between the groups for length of hospital stay (p = 0.56), complications (p = 0.08), conversion to open or radical surgery (p = 0.18), estimated blood loss (p = 0.06), or need for blood transfusion (p = 0.07). The operative time was shorter in the off-clamp group (MD−21.89 min, 95% CI −42.5 to −1.27; p = 0.04) but after sensitivity analysis the difference was no longer statistically significant (p = 0.15). The positive surgical margin rate was significantly lower in the off-clamp group (odds ratio 0.6, 95% CI 0.39–0.91; p = 0.02). CONCLUSIONS: Our review revealed no clinically relevant differences in perioperative and functional outcomes between off-clamp and on-clamp RAPN. PATIENT SUMMARY: In this review, we compared the two methods of controlling the kidney blood vessels during robot-assisted surgery to remove part of the kidney. We noted that there was no difference between the two groups for outcomes such as complications and the decrease in kidney function after surgery.