Perinephric Toxic Fat: Impact on Surgical Complexity, Perioperative Outcome, and Surgical Approach in Partial...

To assess influencing factors on perinephric toxic fat (high Mayo Adhesive Probability [MAP] score) and the impact of high MAP scores on surgical complexity, perioperative outcome, and surgical approach in patients with localized renal tumors undergoing open (OPN) and robot-assisted partial nephrectomy (RAPN).

698 patients were included in this study. Based on preoperative imaging, adherent perinephric fat (APF) was assessed to define MAP scores. Regression analyses assessed influencing parameters for high MAP scores (≥3), predictors of surgical outcome, and influencing factors on surgical approach.

OPN was performed in 331 (47%) patients, and 367 (53%) patients underwent RAPN. Male gender (p < 0.001), age ≥65 (p < 0.001), and BMI ≥27.4 kg/m2 (p < 0.001) showed to be significantly influencing factors for the presence of APF. High MAP scores showed to be an influencing factor for a prolonged surgery duration (OR = 1.68, 95% CI 1.22-2.31, p = 0.002) and a significant predictor to rather undergo OPN than RAPN (OR = 1.5, 95% CI 1.05-2.15, p = 0.027).

Older, male patients with high BMI scores have a higher risk for APF. The presence of APF increases surgery time and may have an impact on decision making regarding the preferred surgical approach.