Objectives: Renal colic (RC) is one of the most frequent reasons for presentation to the emergency department (ED) and creates a high economic and medical burden. Management strategies for RC range from waiting for spontaneous passage to surgical intervention. However, factors determining spontaneous stone passage (SSP) are still poorly understood. Therefore, in this study, we aimed to investigate the role of the systemic immune-inflammatory index (SII) in predicting SSP.
Methods: We retrospectively analyzed the data of 924 patients aged over 18 years, who were diagnosed with RC in our clinic between 1 January 2019, and 30 May 2022, and had ureteral stones of ≤ 10 mm. The patients were divided into two groups according to whether they had SSP. The clinical and laboratory characteristics of the patients in the ED were evaluated. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and SII (neutrophil count x platelet count/lymphocyte count) values of the patients were calculated. Stone size and location were also recorded.
Results: In the univariate analysis of SSP, a ureteral stone size of ≤ 5 mm (p < 0.001), distal ureteral location (p < 0.001), SII (p < 0.001), NLR (p < 0.001), and PLR (p = 0.036) were significantly correlated with SSP. ROC analysis showed that an SII level < 721.8 (Sensitivity %82.6, Specificity %74.7, p < 0.001) was an independent predictor of SSP.
Conclusion: Our findings showed that a low SII level was associated with SSP and could be used as a predictive marker of SSP as a more valuable parameter than NLR. SII and NLR, together with other indicators, are inflammatory markers that can be used in the clinical decision-making process for ureteral stone treatment.
Keywords: Spontaneous stone passage; emergency department; predicting; renal colic; systemic immune-inflammation index.