Spontaneous stone expulsion in patients with history of urolithiasis

To examine differences in the presentation, management, and outcomes of patients admitted to the emergency department (ED) with ureteral stones, with prior history of urolithiasis compared to patients with a first stone event.

Retrospective analysis of patients who visited the ED that were found to have a ureteral stone on CT. Patients were stratified into two groups: without history of urolithiasis (Group 1) and with history of urolithiasis (Group 2).

Between 2018 and 2020, 778 patients were admitted with ureteral stones. Patients in group 1 presented with a higher mean serum creatinine (p = 0.02), larger mean stone size (p < 0.0001), and a higher proportion of proximal ureteral stones (p < 0.0001) than patients in group 2. The 30 day readmission rate was significantly higher in group 1 (p = 0.02). Spontaneous stone expulsion was higher in group 2 (p < 0.0001), whereas the need for endourological procedures was higher in group 1 (p < 0.0001). On multivariable analysis serum creatinine (OR 0.264, 95% CI 0.091-0.769, p = 0.01) and stone size (OR 0.623, 95% CI 0.503-0.771, p < 0.0001) were associated with a lower spontaneous stone expulsion rate. History of prior endourological procedures (OR 0.225, OR 0.066-0.765, p = 0.01) was associated with a higher spontaneous stone expulsion rate.

Our data suggests that patients who are first time stone formers present with larger and more proximal ureteral stones, with a lower likelihood of spontaneous stone expulsion and a subsequent need for surgical intervention. Previous stone surgery and not previous stone expulsion was found to be a predictor for spontaneous stone passage.