Assessing the Trade-off Between the Safety and Effectiveness of Off-clamp Robotic Partial Nephrectomy for Renal Masses with a High RENAL Score: A Propensity Score-matched Comparison of Perioperative and Functional Outcomes in a Multicenter Analysis.

Tumors with a high nephrometry score represent a challenging surgical scenario for which robotic partial nephrectomy (RPN) is a primary option in expert hands.

To compare perioperative and functional outcomes of off-clamp and on-clamp RPN in patients with renal masses with a high RENAL score (≥9).

For this retrospective analysis, an RPN data set including 1604 patients treated at three institutions between 2003 and 2021 was queried for cases with a RENAL score ≥9.

We used 1:1 propensity score matching (PSM) to select a cohort in which imbalances between the off-clamp and on-clamp groups were minimized. We used χ2 and Student t tests to compare categorical and continuous variables, respectively. The Kaplan-Meier method was used to compare the probability of having an estimated glomerular filtration rate (eGFR) ≥45 ml/min during follow-up. Univariable and multivariable analyses were performed to identify predictors of a trifecta outcome (negative surgical margin status, no Clavien-Dindo grade ≥3 complications, eGFR decline ≤30%) and of retaining eGFR ≥45 ml/min over time.

From an overall cohort of 354 patients (142 on-clamp, 212 off-clamp), a homogeneous PSM cohort of 78 patients in each group was selected (p ≥ 0.17). In the PSM cohort, operative time was significantly shorter in the off-clamp group (p < 0.001). There were no differences between the groups in the rates of severe complications (p = 0.32) and positive surgical margins (p = 0.24). The rate of trifecta achievement was significantly higher in the off-clamp group (83.3% vs 67.9%; p = 0.03). Warm ischemia time >20 min was independently negatively associated with trifecta achievement (odds ratio 0.32, 95% confidence interval 0.14-0.74). Moreover, the off-clamp group had a significantly higher probability of retaining eGFR ≥45 ml/min over time (3 yr: 95.9% vs 81.6%; p = 0.03); every 1-min increase in warm ischemia time reduced this probability by 1.3%.

We found a favorable trade-off between the benefits and risks of off-clamp RPN, with similar perioperative outcomes and a net benefit in terms of trifecta achievement and long-term renal function outcomes in comparison to on-clamp RPN.

The complexity of surgery for kidney tumors can be assessed using the RENAL score, which is a measure of the location and size of a kidney tumor. In a multicenter series of patients with tumors with a high RENAL score, we compared outcomes between strategies with (on-clamp) and without (off-clamp) clamping of kidney blood vessels during robot-assisted removal of part of the affected kidney. We found that off-clamp surgery results in better postoperative kidney function.

European urology focus. 2023 May 30 [Epub ahead of print]

Gabriele Tuderti, Riccardo Mastroianni, Umberto Anceschi, Alfredo Maria Bove, Aldo Brassetti, Mariaconsiglia Ferriero, Leonardo Misuraca, Salvatore Guaglianone, Manuela Costantini, Giulia Torregiani, Ava Saidian, Andrea Mari, Rekha Narasimhan, Ithaar Derweesh, Andrea Minervini, Michele Gallucci, Giuseppe Simone

Department of Urology, IRCCS Regina Elena National Cancer Institute, Rome, Italy. Electronic address: ., Department of Urology, IRCCS Regina Elena National Cancer Institute, Rome, Italy., Department of Urology, University of California-San Diego Health System, La Jolla, CA, USA., Department of Urology, Careggi Hospital, University of Florence, Florence, Italy.