IRCCS Ospedale Policlinico San Martino, Genova, Italy
Introduction: The Mayo Adhesive Probability (MAP) score predicts the presence of adherent perinephric fat (APF) which may increase the surgical complexity of partial nephrectomy. We assessed the role of 2D shear-wave elastography (SWE) in predicting the presence of APF with the goal to describe a novel model for the preoperative assessment of patients submitted to robot-assisted partial nephrectomy (RAPN). Methods: Consecutive patients submitted to RAPN were prospectively enrolled between January 2021 and January 2022. Data were collected regarding patients’ characteristics, tumor features (RENAL, PADUA, SPARE score, MAP score ). Presence of APF was defined by the surgeon intraoperatively. Perirenal fat stiffness was preoperatively assessed with two-dimensional (2D) SWE. Each sampling was repeated 3 times and the mean value was recorded. We relied on multivariable logistic regression models to test whether APF was associated with higher values of mean SWE, gender, BMI, and MAP score. Models’ predictive ability of the presence of APF was assessed using the concordance index (C-index). Linear regression models investigated the association between APF and OT. Results: 55 patients were collected of whom 31 (56%) did not have APF and 24 (44%) had APF. No statistically significant differences were reported among patients with or without APF with regards to age, preoperative creatinine and glomerular filtration rate, gender, BMI, smoking habit, diabetes, and cT stage. Hypertension was reported in 17 (71%) out of 24 patients with APF and in 13 (42%) patients out of 31 without APF (p = 0,033). In single-variable analysis, there was a significantly increased likelihood of APF in males (92% VS 8,3% p = 0.004) and in patients with a higher median (IQR) SWE (9.0 (8.0, 11.5) VS 5.8 (4.8, 7.0) p < 0.001). MAP score had a good predictive ability of APF on its own (C-index = 0,876). The model including SWE alone had a similar predictive value (C-index = 0,84). The most effective model in predicting APF included SWE, gender and BMI (C-index = 0,91). The median (IQR) OT was 160 (132 – 182) minutes and 185 (179 – 222) minutes in patients without or with APF, respectively (p = 0,01).The linear regression analysis showed that the presence of APF is associated with higher total OT (R squared = 0,097, p = 0,012). Conclusions: The multivariable model including gender, BMI and the mean value of three measures of SWE highly predicts the presence of APF. The presence of APF impacts the total OT. A larger sample size is needed to validate the model and to create a score that effectively predicts APF. SOURCE OF Funding: -
