Congenital mid ureteral strictures.

Purpose: Congenital mid ureteral stricture is rare. We report 7 cases, and discuss the differences in preoperative evaluation and surgical management compared to other obstructive entities.

Materials And Methods: Medical records and imaging studies of 7 children identified with mid ureteral strictures between 1998 and 2002 were reviewed retrospectively. Five newborns presented with prenatal hydronephrosis, and 2 children presented at age 15 years, one in the course of evaluation of blunt trauma, and one due to pain and abdominal mass. Imaging studies included renal ultrasound, voiding cystourethrography, radionuclide renography and computerized tomography. All patients underwent retrograde pyelography. Pathological examination of each specimen was undertaken at the respective institutions.

Results: Prenatal hydronephrosis was the most common presentation. There were no urinary tract infections. All patients had significant obstruction on the affected side. No patient had vesicoureteral reflux. After imaging but before surgery the urinary obstruction was believed to be at the ureteropelvic junction in 4 patients and the ureterovesical junction in 2, and secondary to posterior urethral valves in 1. At cystoscopy all of the affected ureters had a normally located and normally configured orifice. Retrograde pyelography led to an accurate diagnosis of mid ureteral narrowing in all patients. Six patients underwent ureteroureterostomy, all of whom had satisfactory outcomes. In 1 of these patients contralateral nephrectomy was performed due to nonfunction of the multicystic dysplastic kidney. The remaining patient underwent nephrectomy for ipsilateral end stage kidney disease and hydronephrosis. In this patient the ureters were stenotic and suggested asymmetry in the thickness of the muscular coat, perhaps secondary to extrinsic compression.

Conclusions: Congenital mid ureteral stricture is rare. Renal ultrasound and radionuclide renography alone do not reliably demonstrate the site of obstruction. Retrograde pyelography at the time of surgical correction of presumed ureteral obstruction is an important adjunct for correctly identifying the site of narrowing in the affected ureteral segment, unless the ureter has been imaged with another modality.