Selective by design: early adoption patterns of single-port off-clamp robotic partial nephrectomy in a high-volume center

Abstract

Background: Introduction of single-port (SP) technology into centers with a consolidated multi-port experience in robot-assisted partial nephrectomy (MP-RAPN) represents a conceptual shift rather than a natural transition. We analyzed the early institutional adoption of the SP platform, assessing its impact on case complexity, perioperative outcomes, and determinants of surgical selection within a purely off-clamp RAPN framework compared with the established MP standard.

Material and methods: All consecutive RAPN performed at our tertiary referral center between May 2024 and October 2025 were analyzed (n = 372). All procedures were performed using a standardized off-clamp technique, irrespective of tumor features. After SP platform introduction, cases were stratified as multi-port (MP, n = 294) or single-port (SP, n = 78). Baseline, anatomical, and perioperative variables were prospectively collected. Tumor complexity was graded using the RENAL score, and renal function was assessed through serial eGFR measurements. Continuous and categorical variables were analyzed with Mann-Whitney U and χ²/Fisher tests; SMD > 0.20 denoted clinical imbalance. Univariable and multivariable Firth logistic regression identified independent predictors of SP adoption.

Results: Baseline characteristics were similar (each p > 0.2), except for tumor size and RENAL score, which were lower in SP cases (2.8 vs. 4.1 cm; 6.4 vs. 7.8; each p < 0.001). Perioperative outcomes-including hemoglobin drop, transfusion rate, complications, and hospital stay-were equivalent (each p > 0.05). SP tumors showed higher Fuhrman 1 (20.5% vs. 4.9%, p = 0.008) and pT1a stage (78.8% vs. 52.9%, p = 0.003). A lower RENAL score (OR 0.64, p < 0.001) independently predicted SP selection (C-index = 0.77).

Conclusions: In a center routinely performing purely off-clamp RAPN, adoption of the single-port robotic platform proved technically feasible and oncologically safe, achieving perioperative and functional outcomes equivalent to the multi-port approach during its early institutional phase.

Keywords: Multi-port; Nephron-sparing; Off-clamp; Renal cancer; Robotic partial nephrectomy; Single-port.