Introduction: Robotic partial nephrectomy (RPN) is being increasingly adopted in the management of renal masses amenable to nephron-sparing surgery. Robotic renorraphy techniques, including dual layer repairs, have carried over from laparoscopic partial nephrectomy (LPN) which was initially associated with higher bleeding and urine leak rates compared to open partial nephrectomy (OPN). Dual layer repair has been shown in previous studies to prolong warm ischemia time, while potentially leading to a higher rate of pseudoaneurysm formation and worse long term renal function parameters. Our aim is to compare single cortical robotic renorrhaphy (SCRR) to dual-layer robotic renorrhaphy (DLRR) in terms of bleeding rates secondary to pseudoaneurysm formation, urine leak rates, and long-term renal functional outcomes. Methods: A prospectively maintained list of all RPN procedures at Northwestern Memorial Hospital from January 2018 to July 2022 was retrospectively reviewed. 247 RPNs were identified, including 71 cases with SCRR carried out, and 176 cases with DLRR. Preoperative imaging was used to calculate nephrometry scores using R.E.N.A.L. (radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior, location relative to polar lines, hilar) measurements. Charts of patients with a length of stay longer than 72 hours, or with any readmissions under the urology service were closely examined for bleeding or leakage complications. Other examined parameters included drain fluid-to-serum creatinine ratios, as well as short term and long term changes in glomerular filtration rates (GFR). Results: Comparing SCRR to DLRR, similar nephrometry scores were seen across both groups undergoing RPN (6.6 vs 7, p = 0.29), including equivalent tumor sizes (34 mm vs 30 mm, p = 0.11) and nearness to the collecting system (p = 0.25). No significant differences in rates of bleeding secondary to pseudoaneurysms (0.03% vs 0.02%, p = 0.8), urine leak rates (0% vs 0%), or changes in GFR (p = 0.25) were seen between both groups of this study. Conclusions: No significant changes in urine leakage or bleeding rates secondary to pseudoaneurysm formation or changes in renal functions were found when comparing SLRR to DLRR during RPN for masses of equivalent sizes, depth and nephrometry scores. Single layer cortical repair seems to offer a safe method of shortening renorrhaphy and warm ischemia times compared to dual layer repairs. SOURCE OF Funding: None
