The predictive ability of Mayo adhesive probability score for evaluating intraoperative bleeding in standard percutaneous nephrolithotomy in adult patients.

Mayo adhesive probability (MAP) score is one of the commonest tool to predict the adherence status of perirenal fat. The association between MAP score and intraoperative hemorrhage in patients undergoing micropercutaneous nephrolithotomy was comfirmed in a recent well designed study. We aimed to investigate if MAP score may predict the possibility for significant intraoperative bleeding in supine percutaneous nephrolithotomy (PCNL) performed with a 26 Fr rigid nephroscope. In this observational retrospective study, demographic, clinical, laboratory, radiological, perioperative (operation duration, hospitalization, intraoperative bleeding, success) and MAP score (perinephric fat stranding, posterior perinephric fat thickness and total MAP score) data of all patients who underwent supine PCNL between June 2021 and July 2023 were evaluated. The patients were divided into 2 groups according to their MAP scores (79 [54.1%] patients with MAP score < 3 [low MAP score] and 67 [54.1%] patients with MAP score ≥ 3 [high MAP score]). The rate of patients with intraoperative bleeding was 47.8% in the patient group with a high MAP score, while it was 22.8% in the patient group with a low MAP score (p = 0.002). In multivariate logistic regression analysis, anticoagulant drug use history (OR = 2.525; 95% CI = 1.025-6.224; p = 0.044), presence of multiple stones (OR = 3.015; 95% CI = 1.205-7.543; p = 0.018), calyx localization of the stone (OR = 2.871;95% CI = 1.166-7.068; p = 0.022), higher renal parenchymal thickness (OR = 1.119; 95% CI = 1.049-1.193; p = 0.001) and MAP score > 3 (OR = 3.486; 95% CI = 1.579-7.696; p = 0.002) were defined as independent risk factors for significant intraoperative bleeding. In clinical practice, the MAP score can be used to predict bleeding before PCNL.