Introduction: Percutaneous nephrolithotomy (PCNL) is the standard treatment for large renal stone. Despite the advanced techniques, postoperative fever and bleeding remain the two major complications but still without effective predictor. Mayo adhesive probability (MAP) score is an image-based renal morphometry scoring system that is used to predict the potential risks and complications of partial nephrectomy but was never evaluated for the association with post-PCNL complications. We aim to explore the predictive value of MAP score on postoperative fever and estimated total blood loss (ETBL) in patients underwent miniaturized PCNL (mPCNL). Methods: This is a retrospective study recruiting 159 mPCNL patients from July 2018 to January 2022. MAP scores was determined on the basis of pre-operative computed tomography and was calculated algorithmically by posterior renal fat thickness and the extent of perinephric fat stranding. We used Bourke and Smith formula to calculate intraoperative ETBL. Logistic regression analysis was used to determine independent risk factors associated with fever and ETBL. The predictive values of preoperative urine culture combining MAP score for postoperative fever was determined by receiver operating characteristic (ROC) curve analysis. Results: Among 159 study subjects, over half of the patients presented with MAP score = 3 (n= 90, 56.6%). Men, elderly, chronic kidney disease, and diabetes mellitus were associated with a higher MAP score. The patients with higher MAP score were more likely to have postoperative fever after mPCNL. On multivariate logistic regression, preoperative positive urine culture (OR 2.44, p = 0.01) and a higher MAP score (OR 2.13, p = 0.026) were both significantly associated with postoperative fever. ROC curves analysis combining these two factors on predicting postoperative fever showed AUC 0.73 (0.652–0.810)(fig.1). The posterior perinephric fat thickness was significantly associated with ETBL (ß = 7.36, p= 0.04). Conclusions: The MAP score was associated with postoperative fever in patients undergoing mPCNL, while posterior perinephric fat demonstrated borderline association with estimated perioperative blood loss volume. The combination of preoperative urine culture and the MAP score can significantly predict the probability of fever in patients receiving mPCNL. SOURCE OF Funding: None
.jpg "Chiamin Nina Liu, MD photo")
