Endourology & Stone Disease(구연) (E-167) Expectant management of large ureteral stones measuring 7–10 mm: Predictive factors for spontaneous passage rate and passage interval 충북대학교 의과대학 비뇨의학교실 이희윤, 김경, 서성필, 강호원, 김원태, 김용준, 윤석중, 이상철, 김원재 Purpose: Although shockwave lithotripsy or surgical removal is the preferred treatment for large ureteral stones measuring 7–10 mm, some stones spontaneously passed. We assessed predictive factors for spontaneous passage of large ureteral stones measuring 7–10 mm based on the experience of a single institution. Materials and Methods: Data of 85 consecutive adult patients initially diagnosed by spiral computerized tomography with large ureteral stones measuring 7–10 mm in diameter and managed conservatively at our institution were retrospectively reviewed. Demographic and stone characteristics were compared between patients who experienced spontaneous passage and those who required intervention. Results: Of the 85 patients with large ureteral stones measuring 7–10 mm, 37 (43.5%) passed their stones spontaneously after a mean (± standard deviation) of 13.1 ± 5.5 days. The likelihood of spontaneous passage was higher in patients with stones in the lower ureter than in patients with stones in the upper or mid-ureter (P < 0.001). Multivariate analysis revealed that stone location in the lower ureter was the only significant predictor of spontaneous passage (odds ratio, 8.138; 95% confidence interval, 2.464–26.877, P = 0.001). The time to spontaneous passage was shorter in patients with stones measuring ≤ 8 mm than in patients with stones measuring > 8 mm (P = 0.022). Conclusions: Despite the burden of large stones, 43.5% of patients with large ureteral stones measuring 7–10 mm passed their stones spontaneously. Stone location affected the success rate of spontaneous passage, while stone size was associated with passage interval. keywords : ureteral stone, conservative management, treatment outcome