Association of spontaneous expulsion with C-reactive protein and other clinico-demographic factors in patients with lower ureteric stone

The purpose of our study is to analyze the definitive relation of C-reactive protein (CRP) and other factors with the spontaneous stone passage in patients with distal ureteric calculus of 5-10 mm and to calculate the risk of failure of expectant management in patients. 185 patients of ureteric colic, who were subjected to medical expulsive therapy (MET), were included prospectively from August 2016 to May 2018 and followed up for 4 weeks. Patients were divided into two groups. Group A included successful spontaneous passage patients and group B included failure in the same. The parameters analyzed were age, gender, longitudinal and transverse diameter of stone, CRP, total leucocyte count, ureteric diameter and hydroureteronephrosis (HUN). We performed univariate and multivariate analysis. Receiver operating characteristics curve was used to determine the cutoff value for significantly associated variables. 122 (65.90%) and 63 (34.10%) patients were included in group A and B, respectively. In univariate analysis, CRP, longitudinal and transverse diameter of stone, HUN, proximal and distal ureteric diameters were statistically significant. However, in multivariate analysis, only negative CRP (p = 0.002), smaller longitudinal diameter of stone (p < 0.001) and absence of HUN (p = 0.005) were significantly associated with successful expulsion. Cutoff for CRP was 0.41 mg/dl and longitudinal diameter was 6.7 mm. The success rate in the group of patients with no risk factor was 96.7% and with all three risk factors was 16.7%. Patients with a longitudinal diameter of stone > 6.7 mm, HUN, and CRP > 0.41 mg/dl should be considered for early intervention. The success rate of MET can be increased to 86% after exclusion of patients with all three risk factors.