Clinical predictors and significance of adherent perinephric fat assessed with Mayo Adhesive Probability (MAP) score and perinephric fat surface density (PnFSD) at the time of partial nephrectomy for localized renal mass. A single high-volume referral center experience.

BACKGROUND

Adherent perinephric fat (APF) could negatively influence surgical outcomes of partial nephrectomy (PN). Novel radiological scores have been introduced to preoperatively detect APF, i.e. Mayo Adhesive Probability (MAP) score and perinephric fat surface density (PnFSD). We aimed to evaluate clinical predictors of APF and the association of MAP and PnFSD with perioperative outcomes after PN.

METHODS

Clinical and radiological data of patients undergoing open or robotic PN were prospectively gathered. Perinephric fat was retrospectively measured by a single expert uro-radiologist. Patients were divided into MAP 0-3 vs. MAP 4-5 and high vs. low PnFSD. Multivariable analysis was performed to seek for clinical predictors of APF.

RESULTS

Overall, 175 patients were entered. Patients with vs. without APF were significantly different regarding age, gender, ASA score, Charlson Comorbidity Index, Body Mass Index, waist circumference, HDL status and metabolic syndrome. Conversely, tumor-related characteristics were not significantly different between the groups. At multivariable analysis, metabolic syndrome was confirmed as the only independent predictor of APF (OR: 24.9; P<0.001). Notably, APF assessed by MAP score or PnFSD was not associated with perioperative outcomes after PN.

CONCLUSIONS

In experienced hands, APF did not impact on intra- or perioperative outcomes after PN. Metabolic syndrome was the only significant predictor of APF in our series.