How to pre-evaluate the risk of systemic inflammatory response syndrome in patients undergoing one-stage flexible ureteroscopy lithotripsy？

Background Flexible ureteroscopy lithotripsy (FURL) is widely used to treat Upper urinary tract stone (UUTS). Evaluating whether a patient develops systemic inflammatory response syndrome (SIRS) during and after surgery is one of the most important factors in determining whether a ureteral stent should be placed before FURL. Materials and methods A total of 340 patients with UUTS who underwent one-stage FURL from April 2021 to May 2024 were analyzed retrospectively. Least absolute shrinkage and selection regression and multivariate logistic regression analysis were used to screen out independent risk factors and then developed a nomogram. Concordance index (C-index), receiver operating characteristic curve and calibration curve were used to internal evaluated the predictive ability. We further evaluated the risk of SIRS in one-stage FURL based on the influence of available variables. Results Age, urinary white blood cells, urine bacterial culture and systemic immune-inflammation index (SII) were combined to establish nomogram for prediction the risk of SIRS in one-stage FURL. The SII had the highest odds ratio (OR = 30.356) to SIRS. The C-index (0.964, 95%CI = 0.932–0.996), area under curve (0.935), and calibration curve demonstrated the favourable predictive ability of nomogram prediction. We further developed a scoring system and classified the risk of SIRS into four grades. Conclusion The established nomogram and risk scoring system have favourable predictive ability and clinical serviceability to personalize predict the SIRS risk in UUTS patients undergoing one-stage FURL. A ureteral stent should be placed before FURL in patients with SII greater than 1300 and one of the following: age>60 years, urinary white blood cell 1+/2+/3+, or urine bacterial culture positive. We present the first study to evaluate the value of preoperative SII on FURL. The proposed new insights may help clinicians select safer treatment for UUTS patients.