Surgical and Perioperative Outcomes of robot assisted partial nephrectomy: a comparative analysis of single versus double layer renorraphy

Surgical and Perioperative Outcomes of robot assisted partial nephrectomy: a comparative analysis of single versus double layer renorrhaphy Giacomo Novara, Giuseppe Reitano, Claudia Colbacchini, Anna Gambarotto, Riccardo Cardia, Fabio Zattoni, Fabrizio Dal Moro Objective To compare the clinical characteristics, major intraoperative and postoperative features among patients undergoing RAPN with single-layer or double-layer renorrhaphy at a tertiary referral center. Materials and methods Between October 2020 and June 2025, 493 patients underwent RAPN using the Da Vinci system. Cortical renorrhaphy was performed in 102 cases, while a single-layer medullar renorrhaphy was performed in 391 patients. Anatomical complexity of the tumor was assessed with the PADUA score. Intraoperative complications were stratified according to Satava classification; postoperative complications were categorized according to the Clavien Dindo grading system. Continuous variables were summarized using median and interquartile ranges (IQR). Predictors of cortical renorrhaphy utilization and of complications were evaluated by univariate and multivariate analysis. Statistical significance was considered for values of p<0.05. Results Median BMI was 25 (23-29) for patients who underwent cortical renorrhaphy (group 1) and 26 (24-29) for those who underwent a single-layer renorraphy (group 2), (p=0.7). The median Charlson score was 3 (1-4). Most of the patients underwent previous abdominal surgery, 54 (59%) in group 1 and 206 (56%) in group 2 (p=0.5). The median tumor size was 34 (25-50) in group 1 and 35 (25-45) in group 2 (p=0.6). Most of the patients in group 1 had a PADUA score of 7 (20, 23.8%). Also, the most frequent PADUA score in group 2 was 7 (86, 23.4%) Transperitoneal access was the most common approach (449, 92%). Median surgical time was 125 min (100-165) in group 1 and 125 min (100-155) in group 2 (p=0.7). Arterial clamp was performed in 389 cases (79%) with warm ischemia time of 12.5 min (8-18) in group 1 and 13 min (7-18) in group 2 (p=0.8). The number of perioperative transfusions was 3 (1.6%) in group 1 and 5 (6%) in group 2. Satava 1-2 complications occurred in 3 patients (2.9%) in group 1 and 14 patients (3.6%) in group 2. No differences were found in 90-day postoperative complications (p=0.5). High-grade 90-day (Clavien-Dindo > 2) complications were 2 (2.3%) in group 1 and 16 (4.4%) in group 2 (p=0.4). Hospital stay was 2 days (1-4) in group 1 and 2 days (1-3) in group 2 (p=1.0). Positive surgical margin rate was 5.9% (n=29). BMI, CCI and PADUA score were found to be independent predictors of complications in the postoperative period, renorrhaphy type was not a predictor of complications. ASA score was a predictor of high-grade complications. Conclusions Cortical renorrhaphy can be safely omitted without impact in terms of postoperative complications, need for perioperative transfusions and length of hospital stay.