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. Patient summary: In this study, we evaluated peri- and postoperative outcomes of patients treated with partial nephrectomy for complex renal masses. Open surgery was associated with higher complications than the robotic approach. Some histological features were found to be associated with disease recurrence.