Perioperative and Mid-term Oncological and Functional Outcomes After Partial Nephrectomy for Complex (PADUA Score ≥10) Renal Tumors: A Prospective Multicenter Observational Study (the RECORD2 Project)

Background: Partial nephrectomy (PN) for complex renal masses has a non-negligible risk of perioperative complications. Furthermore, late functional and oncological outcomes of patients submitted to these challenging surgeries still remain to be determined. Objectives: To report the perioperative and mid-term oncological and functional outcomes of PN for complex masses (Preoperative Aspects and Dimensions Used for an Anatomical [PADUA] score≥10) in a large multicenter prospective observational study. Design, setting, and participants: We prospectively evaluated patients treated with PN for complex renal tumors at 26 urological centers (Registry of Conservative and Radical Surgery for Cortical Renal Tumor Disease [RECORD2] project). Outcome measurements and statistical analysis: Multivariate logistic regression analyses explored the predictors of surgical complications. Multivariable Cox regression analyses estimated the hazard of renal function loss and disease recurrence. Kaplan-Meier estimates assessed the probability of survival. Results and limitations: In total, 410 patients who underwent PN for complex masses were evaluated. Clinical T1b and T2 tumors accounted for 43.2% and 9.8% of the cases. Overall, 45.9%, 18.8%, and 35.4% of patients underwent open, laparoscopic, and robotic PN, respectively. Intraoperative complications occurred in 15 (3.6%) patients, while postoperative surgical complications were recorded in 76 (18.5%) patients. At multivariable analysis, preoperative hemoglobin (odds ratio [OR]: 0.67; p<0.001) and open (OR: 3.91; p<0.001) versus robotic surgical approach were found to be the only predictors of surgical complications. An estimated glomerular filtration rate drop of >25% from baseline was observed in 30.2% and 17.6% of patients at 1st month and 2 yr after surgery, respectively. Two-year recurrence-free survival was 97.1%; positive surgical margins (hazard ratio [HR]: 3.35; p=0.009), nucleolar grading (HR: 5.61; p<0.001), and tumor stage (HR: 2.62; p=0.05) were associated with recurrence. Conclusions: In a large series, PN for complex renal masses was a safe technique with an acceptable rate of perioperative complications and excellent mid-term oncological and functional results.