Congenital valves of the ureter. Comments on 7 cases studied in childhood]

Ureteral valves are a rare cause of congenital obstructive uropathy in pediatric age. Symptoms onset is variable and depends directly on the degree of valvular obstruction. Seven cases of ureteral valves were studied in the Radiology Department of "Bambino Gesù" Pediatric Hospital in Rome; every type of technique available in the hospital was employed. For each case, the authors carefully describe the clinico-radiological approach which led to the diagnosis of obstruction due to the presence of one or more valvular structures (hydronephrosis). Intravenous urography proved to be the most sensitive examination to confirm the diagnosis of suspected obstruction made on the basis of US findings, and to assess its precise location. Segmental ascending pyelography was also employed, which consists in cystoscopically inserting a ureteral catheter into the renal pelvis, and then administering a contrast medium which allows the fluoroscopic visualization, both above and below the stricture, of the ureteral segments. The technique also allows the detection of other valves of the same ureter not otherwise recognizable. All 7 patients underwent surgery; follow-up at 12 months demonstrated clinical symptoms regression and a good functional and morphological recovery of the involved ureter.