Abstract：Objective To analyze the incidence and risk factors of urinary sepsis after minimally invasive percutaneous nephrolithotomy (mPCNL) in large renal calculus patients, and to construct a nomogram prediction model for clinical diagnosis of urinary sepsis.Methods A retrospective analysis was performed on 188 patients with large kidney stones (longest diameter ≥25 mm) diagnosed in our hospital from February 2017 to February 2022. All patients were treated with single-channel holmium laser mPCNL. Seven days after surgery, patients were divided into sepsis group (28 cases) and no sepsis group (160 cases) according to the diagnostic criteria of the European Society of Urology guidelines on urogenic sepsis. The risk factors of urogenic sepsis were screened by univariate and multivariate logistic regression analysis, and the nomogram model was established.Results Single-actor comparison showed that the preoperative urinary white blood cell count, urinary nitrite positive rate, positive rate of stones in adjacent calyces, maximum cross-sectional area of stones, diameter of hydronephrosis, positive rate of urinary bacterial culture and operation time after mPCNL in sepsis group were significantly increased compared with those in non-sepsis group, with statistical significance (all P<0.001). Multivariate logistic regression analysis showed that urine white blood cell count, urine nitrite positive, stone positive in adjacent calyces, stone maximum cross-sectional area and hydronephrosis diameter were independent risk factors for urogenic sepsis (all P<0.001). R software built a nomogram model, with a total score of 220. Receiver operating characteristics (ROC) curve results showed that the area under the curve (AUC) predicted by the nomogram for urogenic sepsis was 0.876 (95%CI：0.810～0.923). The calibration curve was drawn to show that the model evaluation was in good agreement with the actual results.Conclusions Large renal calculi after mPCNL have a certain risk of urogenic sepsis. Preoperative urinary leukocyte count, urinary nitrite positive, adjacent renal calyceal calculi positive, maximum cross-sectional area of calculi and diameter of hydronephrosis are the independent risk factors.Establishment of a simple and visual nomogram model has good value in guiding clinical prediction of urogenic sepsis, which is worthy of popularization.
