Objectives: Flexible ureteroscopic lithotripsy (FURL), as a common method for treating upper urinary tract calculi, has the risks of complications such as infection and bleeding. Especially, systemic inflammatory response syndrome (SIRS) after FURL may induce multiple organ dysfunction threatening the lives of patients. We aimed to investigate the clinical characteristics and risk factors of SIRS after FURL.
Methods: A total of 157 upper urinary tract calculus patients treated with FURL from January 2018 to December 2019 were enrolled, and clinical outcomes and complications were analyzed. Patients were divided into SIRS group (n = 31) and non-SIRS group (n = 126) according to the presence or absence of SIRS after FURL. Their clinical data were compared by univariate analysis, and the factors with statistically significant difference were incorporated into LASSO logistic regression analysis. The model was visualized using a nomogram, and model discrimination and accuracy were verified.
Results: The results of univariate analysis indicated that there were significant differences in gender, average stone size, preoperative urinary white blood cell count, surgery time and postoperative stone bacterial culture between the two groups. The results of LASSO logistic regression analysis showed that the above factors were independent risk factors for patients with SIRS. The C-index of the SIRS risk prediction model was 0.992. The area under the ROC curve of this model was 0.944 (95% CI: 0.913-0.997), the sensitivity was 97.9%, and the specificity was 95.8%. The average absolute error between actual and predicted risk probabilities was 0.028. The model for predicting the risk of SIRS had good discrimination and high consistency with the actual observed value.
Conclusions: Females, larger stones, higher preoperative urinary white blood cell count, longer surgery time and postoperative positive stone bacterial culture are independent risk factors of SIRS after FURL for upper urinary tract calculi.
Keywords: flexible ureteroscopic lithotripsy; nomogram model; risk factor; systemic inflammatory response syndrome; upper urinary tract calculus.