[Etiopathogenesis of so-called congenital hydronephrosis]

Taking up again inquiries already known in the past, documents of pathological anatomy of his own person experience, and facts of embryology, the authors explain the etiology of the obstructive malformation of pyelo-ureteral function the etiology brings out two phenomena: --The insufficient hollowing of the cephalic end of the ureteral bud, which is initially grooved, when it detaches itself from the Wolffian canal, can transform itself into a full cellular cord which secondarily forms a groove after 23 mm stage.--The insufficient vascularization of the ureter just below the pelvis because of an abnormal anatomical disposition which causes displacement of the longitudinal uretero-pelvic arteries to a point clearly below the ureteropelvic junction. There an ischemia impedes the muscular development of the ureter just below the pelvic of which the wall becomes more sclerotic and fibrous than muscular. Thus a defect in the grooving of the ureteral bud and an arterial blood deficit results in a congenital ureteral stenosis. Pathological anatomical documents illustrate this theory from which flow two imperative technics; the necessity to eliminate the initial obstructive ureteral segment; care to protect the pelvic vessels which will have to vascularize the ureter which will be anastomosed to the cut edge of the pelvis.