Anatomical basis of a common embryological origin for epispadias and bladder or cloacal exstrophies.

Epispadias, bladder exstrophy and its variants are in the first place usually considered as urological anomalies. Embryological theses and therapeutic approaches are mainly based upon this aspect. We challenge this point of view, in order to bring out a new axis of research about this still misknown pathologic field. A review of 16 cases of bladder exstrophy, 6 epispadias cases, and one cloacal exstrophy case, which had never been described before, revealed that the almost constant bony defect of the pelvic ring was linked with the severity of the visceral features, and with the continence status in epispadias cases. The commonly admitted theories about exstrophy development are based on a primary defect of the cloacal membrane. We suggest that the first anomaly could lie in a lack of rotation in the pelvic ring primordia.