[The phenomenon of obstructive uropathy with minimal or no dilatation]

Obstructive anuria does not necessarily show a marked dilatation of the urinary tract on evaluation with imaging techniques. A case with acute renal failure of this type is presented. We discuss why this condition is caused and how diagnosis can be made quickly. Likewise, we discuss the length of time we can defer renal diversion before rupture of the collecting system supervenes and, consequently, urinary extravasation.