Kırlı EA, Bülbül E, Kaygısız O, et al. - In children undergoing semi-rigid ureterorenoscopy (URS), increased ureteral wall thickness (UWT) was related to adverse outcomes of this procedure attributable to tissue hypertrophy, edema, and mucosal bleeding may result in difficulty in stone removal. An increased risk of complications might be conferred by thick ureteral wall, because of the necessity of manipulating the instruments or the involuntary forceful use of instruments while removing the stone.

• This study included 89 children who had URS and had undergone non-contrast abdominal computerized tomography prior to the URS.

• In ROC analysis, a UWT value of 4.5 mm was identified as the optimal cut-off value predictive of the URS outcome, with sensitivity 60%, specificity 92%.

• In regression analysis, independent risk factors for residual stone were: UWT > 4.5 mm and multiple stone presentation.

• A total of 15 (17%) children developed complications, and thick ureteral wall and longer operative time were independent risk factors for complications.