Blind-ending duplications of ureter

Experience with blind-ending duplications of the ureter is reviewed, and a classification of four types is presented. The incidence, methods of diagnosis, symptoms, embryology, and therapy are reviewed. The fourth type, a doubly blind-ending duplication surrounding an otherwise normal ureter, is presented for the first time. In this case, it is associated with reflux by disturbing the anatomy of the intramural ureter and its valve-like function. Surgical exploration is required for diagnosis.