On-Clamp vs. Off-Clamp Robot-Assisted Partial Nephrectomy for cT2 Renal Tumors: Retrospective...

Area of Science:

• Urology
• Surgical Oncology
• Robotic Surgery

Background:

• Robot-assisted partial nephrectomy (RAPN) is a standard treatment for renal masses.
• The impact of hilar clamping strategy (on-clamp vs. off-clamp) on perioperative outcomes for large renal tumors (>7 cm) remains under investigation.
• Assessing surgical quality using the Trifecta achievement (negative margins, no severe complications, ≤30% eGFR reduction) is crucial.

Purpose of the Study:

• To compare perioperative outcomes between on-clamp and off-clamp RAPN for large renal masses (cT2N0M0).
• To evaluate the association between hilar clamping duration and surgical outcomes.
• To determine if off-clamp RAPN is a safe and viable alternative for treating large renal tumors.

Main Methods:

• A multicenter retrospective analysis of 316 patients undergoing RAPN for cT2N0M0 kidney tumors (July 2007-February 2022).
• Propensity-score matching created two comparable cohorts (n=89 each) based on age, ASA score, preoperative eGFR, and RENAL score.
• Comparison of operative time (OT), severe రక్త loss (sRFD), and Trifecta achievement rates between on-clamp and off-clamp groups.

Main Results:

• The off-clamp RAPN group had significantly shorter OT (80 vs. 190 min, p<0.001) and a lower incidence of sRFD (22% vs. 40%, p=0.01) compared to the on-clamp group.
• Trifecta achievement rates were significantly higher in the off-clamp group (66% vs. 46%, p=0.01).
• Crude analysis revealed that >20 min of hilar clamping was associated with increased sRFD risk (OR: 2.30) and reduced Trifecta probability (OR: 0.46).

Conclusions:

• Purely off-clamp RAPN is a safe and viable approach for treating large cT2 renal masses.
• The off-clamp technique may offer superior perioperative surgical outcomes compared to the on-clamp method.
• Minimizing hilar clamping time is associated with better surgical quality and reduced complications in RAPN.