LAUSR

Introduction: Ureter stones leading to severe pain and urosepsis are usually treated by emergency primary ureteral stenting. However, this intervention can significantly change the location of the stone, potentially also changing the preferred method and/or technical aspects of definitive treatment. We analyzed stone location changes and consequences after emergency ureteral stent insertion prior to secondary ureterorenoscopy. Methods: We performed a retrospective analysis of stone locations in 649 patients with a mean age of 52 ± 16 years who were treated with ureterorenoscopy for symptomatic stones from May 2016 to December 2019. All patients with single unilateral ureterolithiasis undergoing definitive stone treatment by secondary ureterorenoscopy were included. In 469 patients, ureteral stone localization before emergency ureteral stenting and at subsequent ureterorenoscopy was evaluated. Additionally, the use of flexible ureterorenoscopy for complete stone removal was also recorded. Results: Inadvertent repositioning of ureteral stones with a mean diameter of 6.9 (±3.1) mm after ureteral stenting was observed in 45.6%. 119 (25.4%) ureteral stones were displaced back into the kidney. Proximal stones showed a particularly high incidence of repositioning into the renal pelvis (42%, p < 0.05). The majority of cases required the use of flexible ureterorenoscopy showed a primary proximal ureteral localization (60 of 85 patients, 70.5%). Discussion/Conclusion: Emergency ureteral stenting for ureterolithiasis may change the location of a stone, potentially affecting therapy planning, particularly in the case of proximal stones. Imaging control prior to definitive stone treatment is thus especially advisable for proximal ureteral stones.