Prevalence and predictors of stone passage after double J stenting for symptomatic ureteral stones: a cross-sectional, real-life study

Abstract

Purpose: To evaluate the rate of and predictors of stone passage (SP) after urgent retrograde stenting for symptomatic ureteral stones.

Methods: We retrospectively analysed data from 249 consecutive patients presenting to the emergency department for symptomatic ureteral stones and treated with retrograde stenting. Demographic, clinical and laboratory characteristics were collected. Stones parameters were collected before stenting and SP was evaluated at 1 month with computerized tomography. Descriptive statistics and logistic regression models tested the association between predictors and SP.

Results: Overall, median (IQR) age and stone diameter were 56 (45-68) years and 7.1 (4.4-9.8) mm, respectively. Stones were located in the proximal, mid and distal ureter in 102 (41.0%), 48 (19.3%) and 99 (39.8%) cases. SP was observed in 65 (26.2%) individuals. Stone diameter (3.2 vs. 7.7 mm, p < 0.001) and stone density (416 vs. 741, p < 0.001) were lower and a higher rate of distal stones (76.9% vs. 26.7%, p < 0.001) was found in the SP group compared to that with persistent stones. Multivariable logistic regression analysis showed that distal ureteral stone location (OR 7.9, p < 0.01) and lower HU (OR 0.9, p < 0.01) were associated with SP, after accounting for stone volume. Patients with a distal stone of 500 HU had a 75% probability of SP.

Conclusion: Stone passage occurred in 26% of patients with indwelling stent due to symptomatic ureteral stones. Lower stone density and distal stone location were independent predictors of stone passage. Patients with these criteria should be managed with follow-up imaging and stent removal instead of ureteroscopy.

Keywords: Emergency; Renal colic; Risk score; Stenting; Stone; Stone passage.