Off-clamp vs on-clamp robotic partial nephrectomy: Perioperative, functional and oncological outcomes from a propensity-score matching between two high-volume centers.

Aim of the study was to compare perioperative, functional and oncological outcomes after off-clamp vs on-clamp robotic partial nephrectomy (RPN).

Patients who underwent off-clamp or on-clamp (warm ischemia) RPN were extracted from 2 institutional prospectively-maintained databases. 123 patients who underwent off-clamp RPN at one institution were excluded, so that each institution contributed with unselected patients (institution 1:on-clamp RPN vs institution 2:off-clamp). 2:1 propensity-score matching (age, sex, smoking, diabetes, hypertension, ASA score, solitary kidney, preoperative eGFR, tumor size and R.E.N.A.L.score). Perioperative outcomes were compared. A linear mixed model was fitted to eGFR as the outcome regressed on fixed effects for 1) management of clamping (on-clamp/off-clamp), 2) time (at baseline, at discharge, at 12 and 24 months postoperatively), and 3) clamp/time interaction. Survival events were compared between groups.

1983 patients were pooled. After matching, 400 on-clamp vs 200 off-clamp patients were analyzed. No significant differences were found in key perioperative outcomes. The effect of on-clamp on eGFR changed over time. At discharge, groups had similar drop in eGFR. The difference between groups was greatest at 12-months postoperatively, with on-clamp patients showing a deficit of 5 ml/min. At 24-months follow-up, this gap shrunk to 2 ml/min. There were no significant differences in overall survival (p = 0.1), recurrence (χ2 = 0.008, p = 0.9), or metastasis free survival (χ2 = 0.962 p = 0.3). Only one cancer-specific death occurred in off-clamp group.

We confirm no significant differences in the perioperative and oncological outcomes between off-clamp and on-clamp RPN. Avoided ischemia benefits renal function within 1-year follow-up after surgery. At longer follow-up, difference with on-clamp is softened.

European journal of surgical oncology : the journal of the European Society of Surgical Oncology and the British Association of Surgical Oncology. 2018 Dec 09 [Epub ahead of print]

Riccardo Bertolo, Giuseppe Simone, Juan Garisto, Georges Nakhoul, Sherif Armanyous, Jose Agudelo, Manuela Costantini, Gabriele Tuderti, Michele Gallucci, Jihad Kaouk

Glickman Urological and Kidney Institute, Department of Urology, Cleveland Clinic, Cleveland, OH, USA., Department of Urology, "Regina Elena" National Cancer Institute, Rome, Italy., Glickman Urological and Kidney Institute, Department of Nephrology, Cleveland Clinic, Cleveland, OH, USA., Glickman Urological and Kidney Institute, Department of Urology, Cleveland Clinic, Cleveland, OH, USA. Electronic address: .