Types 1 (VUR)

IVU and VCUG in a 6-year-old girl with reflux prior to surgery (on the left) and after surgery (on the right). Prior to surgery, a complete ureteral duplication is visible in the IVU, which means that both ureters enter the bladder separately; the VCUG shows only the ureter and pelvis of the lower part of the kidney. After surgery both ureters have seemingly a common distal tract in the IVU; in the VCUG the ureter and pelvis of the the lower renal part are not visible anymore. The diagnosis is complete ureteral duplication of the left side (= duplex ureter). In more than 90 % of these cases there is an insufficiency of the vesicoureteral valve of the lower kidney due to a lateralization of the orifice. This is an example of a primary reflux due to an anomaly of the orifice. Other causes of primary reflux are retardation of the maturation of the valve, or cystitis. In contrast to the malformation of the orifice, the reflux may disappear with growth or treatment of cystitis with antibiotics. During reimplantation of both ureters en bloc (which means the fibrous connections between the two ureters are not released) the ureters are removed from the bladder wall, if necessary somewhat resected, and reimplantated together into the bladder; the approximation of the ureters following surgery causes the impression of a common distal tract in the IVU.