Evaluating blood and urinary markers for prediction of spontaneous ureteral stone passage.

Abstract

Objectives: The predictive value of blood and serum markers for spontaneous ureteral stone passage (SSP) has been investigated, with no substantial conclusion about their reliability. Therefore, we aim to evaluate the predictive potential of blood and urine laboratory tests for ureteral stone passage.

Methods: This prospective, single-center observational study included patients with a solitary obstructing ureteral stone <10 mm diagnosed via non-contrast computerized tomography (NCCT). Definition for SSP was strict including physical evidence of stone passage, follow-up NCCT, or ureteroscopy, and patients were followed until stone passage or urologic intervention occurred. Blood and urine markers, including white blood cells count (WBC), neutrophil-to-lymphocyte ratio (NLR), creatinine, calculated glomerular filtration rates, urine leukocyte esterase and nitrates were collected. Univariate analysis, multivariate analysis, and receiver operating characteristic curves were performed to assess the association between markers and SSP.

Results: Cohort consisted of 165 participants who met the inclusion and exclusion criteria with adequate data collection and follow-up. Median age was 54 years with a male to female ratio of 11:5. Most stones were in the mid-distal ureter (56%) and median stone size was 3.5 mm. SSP was observed in 87 patients (53%). None of the blood or urine markers demonstrated a significant association with SSP, and areas under the curves were poor and insignificant. Smaller stone size and distal location significantly predicted SSP.

Conclusions: Routine blood and urine markers are not associated with SSP, and their contribution to SSP nomograms might be negligible. These negative results may redirect providers' focus to other factors when predicting SSP.