Coexisting ureteropelvic junction obstruction and vesicoureteral reflux: diagnostic and therapeutic implications.

The coexistence of ureteropelvic junction obstruction and vesicoureteral reflux was seen in 17 (14 per cent) of 147 consecutive patients undergoing pyeloplasty. These patients were analyzed to determine the therapeutic implications of this association. They fell into 3 clinical groups: group 1--primary ureteropelvic junction obstruction, group 2--ureteropelvic junction obstruction secondary to high grade reflux and group 3--pseudo-ureteropelvic junction obstruction. There were 11 patients in group 1. These patients had incidental low grade reflux. Pyeloplasty should be the initial procedure with use of a nephrostomy tube or Foley catheter postoperatively. Vesicoureteral reflux resolved spontaneously with linear growth in approximately half of the cases. There were 4 patients in group 2. The obstructive uropathy should be treated initially, since primary ureteral reimplantation may provoke acute ureteropelvic junction decompensation. There were 2 patients in group 3. Pseudo-ureteropelvic junction obstruction is suggested when pelvic dilatation on the voiding cystourethrogram suggests obstruction but drainage films or antegrade studies document good drainage. The recognition of pseudo-ureteropelvic junction obstruction is important to avoid surgery on a ureteropelvic junction that is not obstructed. Primary correction of the reflux is appropriate. However, it must be recalled that a fixed kink may rarely develop later leading to true secondary ureteropelvic junction obstruction, which will require surgical correction. We recommend that a voiding cystourethrogram be part of the routine evaluation of children with suspected ureteropelvic junction obstruction.