Open and Laparoscopic Partial Nephrectomy: Comparison and Validation of Preoperative Scoring Systems, Including PADUA, RENAL, ABC Nephrometric Scores and Perinephric Fat Evaluation with Mayo Adhesive Probability Score

Purpose: To evaluate potential associations between 4 nephrometric scoring systems, namely the PADUA (preoperative aspects and dimensions used for anatomical classification), RENAL (radius endophytic/exophytic nearness anterior posterior location), ABC (arterial-based com- plexity), and MAP (Mayo adhesive probability) scores and their individual components, with surgical and oncological outcomes of patients undergoing a partial nephrectomy.
Materials and Methods: A consecutive, monocentric cohort of partial nephrectomy patients was retrospectively analyzed. PADUA, RENAL, ABC and MAP nephrometry scores were determined from preoperative axial images. Unadjusted and adjusted associations between overall scores, individual components, surgical approach, complications and onco- logical outcomes were determined using univariate and multivariate logistic regressions. Results: A total of 189 partial nephrectomies were performed in 181 patients, via an open or a laparoscopic approach. Among scoring systems, only the MAP classification, which assesses adherent perinephric fat, was associated with severe surgical complications as well as with operative time (p<0.05). Among all components of the PADUA and RENAL scores, only proximity of the tumor to the collecting system was associated with overall surgical complication rates, while the diameter of the tumor influenced the operative time (p<0.05). The ABC score was not relevant. Male gender, antiplatelet therapy, and a laparoscopic approach were associated with higher overall surgical complication rates (p<0.05). The number of oncologic recurrences during follow-up was too low to run statistical analyses.
Conclusion: Nephrometry scores could be simplified to predict surgical complications after partial nephrectomy. In this framework, adherent perinephric fat seemed to be strongly associated with an increased risk of surgical complications.