Off-clamp robotic partial nephrectomy is a safe and effective approach for patients with T1b or greater renal tumors.

Robotic partial nephrectomy (RPN) is a gold standard treatment for focal kidney tumors. Off-clamp RPN avoids prolonged ischemia times. We sought to evaluate the safety and efficacy of off-clamp RPN in patients with renal tumors > 4 centimeters (cm). From 2007 to 2021, we examined patients who underwent RPN for cT1b-T2N0M0 renal tumors. Preoperative, intraoperative, and postoperative outcomes were examined for patients who underwent on or off-clamp RPN. Patients with cT1b tumors (4-7 cm) who underwent either approach were retrospectively propensity-matched based on renal function and tumor size. Of 225 patients, on-clamp RPN was employed in 147 patients, while 78 patients underwent an off-clamp approach. Preoperative estimated glomerular filtration rate (eGFR) was significantly lower in the off-clamp group (p = 0.026). Mean nephrometry scores and mean tumor sizes were similar between cohorts. Average estimated blood loss (EBL) and operative times were similar. Major complication risk was 4.4% lower in the off-clamp group. Blood transfusion rate was 5.6% lower in the off-clamp group. Patients in the off-clamp cohort experienced a < 2% higher risk of positive margins. Postoperative eGFR was more favorable for off-clamp RPN following surgery at 1 year. The propensity-matched analysis demonstrated similar intraoperative outcomes. Blood transfusion rate was significantly lower at 1.5% for patients who underwent off-clamp RPN (p = 0.03). Risk of a major complication was 6.1% lower in the off-clamp RPN cohort, while postoperative eGFR and positive margin rates were similar between off and on-clamp groups. A non-inferior approach for patients with cT1b-T2N0M0 and moderately complex localized renal masses is off-clamp RPN.