Cohen Cross-Trigonal Ureteral Reimplantation: Is a One-Year Postoperative Renal Ultrasound Scan Necessary After Normal Initial Postoperative Ultrasound Findings?

Objectives: To determine the utility of the 1-year postoperative renal ultrasound scan in children undergoing uncomplicated Cohen cross-trigonal ureteral reimplantation. Methods: A retrospective review of 108 patients (233 ureters) who had undergone uncomplicated Cohen cross-trigonal ureteral reimplantation during a 6.5-year period with a postoperative follow-up of 1 year was performed. Renal ultrasound scans were obtained at 1 month and 1 year postoperatively. Results: Of the 108 patients who had undergone ureteral reimplantation, 26 patients (24%) had mild to moderate hydronephrosis at 1 month postoperatively. Of these 26 patients, 20 had preexisting hydronephrosis and 6 had new hydronephrosis. Of the 20 patients with preoperative hydronephrosis, 19 (95%) had similar hydronephrosis on the 1-month postoperative ultrasound scan and in 1 (5%), the hydronephrosis had resolved. At 1 year, 13 (69%) of the 20 patients with preoperative hydronephrosis had stable hydronephrosis, and it resolved in 6 (31%). In the 6 patients with new-onset hydronephrosis at 1 month postoperatively, the hydronephrosis had resolved by 1 year in 4 patients (67%) and was mild in 2 (33%). Three patients developed transient obstruction requiring stent placement. Conclusions: It has been recommended that a renal ultrasound scan be obtained in children 1 year after open ureteral reimplantation to rule out delayed obstruction. Our results suggest this is of low yield in patients with uncomplicated open ureteral reimplantation.