[Acute hydronephrosis in children].

Out of 350 cases of hydronephrosis due to malformation of the ureteropelvic junction, seventeen were acute. Two of these cases, localized in a single kidney, induced anuria in one case, and rupture of the kidney in the other (a baby aged 17 days). The fifteen other cases were revealed by an extremely painful symptomatology, which might have led to severe diagnostic errors. The diagnosis relies on IVU during the period of pain, visualizing a kidney which is barely functioning, if at all. An aberrant vessel was found on the lower pole in 75 per cent of cases, but this, like infection, is only an aggravating factor, though infection may necessitate temporary diversion by cutaneous nephrostomy. All fifteen patients were treated by ureteropelvic resection, and the results were always better than for chronic hydronephrosis because the calicopelvic dilatation is reversible in acute hydronephrosis, and the renal parenchyma still function correctly.