Response to Cracco re: Two Are No Different Than One: Ureteral Duplication Appears to Have No Effect on Ureteroscopy Outcomes by Chertack et al.

Introduction: Ureteral duplication is the most common ureteral anomaly, occurring in 0.6%-0.7% of the population. Our objective was to compare urolithiasis treatment outcomes in patients with and without ureteral duplication. Methods: Patients with ureteral duplication who underwent ureteroscopy (URS) were identified in a stone registry at a high-volume, tertiary care center from 1998 to 2015. Preoperative, intraoperative, and postoperative data were collected retrospectively. A 1:1 control cohort of patients without duplication was identified, matched by stone location and size, as well as age, body mass index (BMI), and gender. Clinical data and outcomes were compared between duplication and control groups, between partial and complete duplication groups, and between patients in whom duplication was identified intraoperatively vs known preoperatively. Results: Fifty patients with ureteral duplication who underwent URS were identified and were matched to 50 control patients. Patients with ureteral duplication required longer operative time (55 minutes vs 38.5 minutes, p = 0.022). Ureteral duplication had no effect on stone-free rates or need for additional procedures. High-grade (Clavien 4-5) complications were similar in both groups (4% vs 4%). Location of ureteral duplication and preoperative knowledge of ureteral duplication did not affect operative time or stone-free rates. Conclusions: Patients with ureteral duplication undergoing URS for urinary stone disease have longer operative times. Preoperative knowledge of ureteral duplication appears to have no significant effect on URS's safety or efficacy. In patients without a prior diagnosis of ureteral duplication, our data suggest that intraoperative detection via endoscopy and fluoroscopy is sufficient to safely and completely treat stone disease.