INCIDENCE AND NATURAL-HISTORY OF CONTRALATERAL VESICOURETERAL REFLUX IN PATIENTS PRESENTING WITH UNILATERAL DISEASE

Purpose: The new onset of contralateral vesicoureteral reflux after th e surgical correction of unilateral disease has been well documented a nd it is attributed to the surgical procedure. However, to our knowled ge the spontaneous development of contralateral reflux in patients tre ated nonoperatively for unilateral disease has not been documented pre viously. We evaluated the incidence and natural history of contralater al reflux in children presenting with initially unilateral disease. Ma terials and Methods: We reviewed the records of 130 girls and 13 boys with a mean age of 29.1 months presenting with primary unilateral refl ux between 1983 and 1996. The grade of and time to new onset contralat eral reflux were noted. Whereas the initial radiological diagnosis rel ied on contrast voiding cystourethrography, followup evaluation includ ed contrast and radionuclide voiding cystourethrography. The upper tra cts were assessed by ultrasound and/or excretory urography, and cortic al renal scans were performed selectively. Results: Patients were foll owed a mean of 32.2 months (range 4.6 to 147). Of the 143 patients 135 presented with a febrile urinary tract infection, and in 14 reflux wa s associated with a ureteral duplication anomaly. At presentation refl ux was grade I or II in 110 patients, grade III in 26 and grade IV or V in 6. Followup voiding cystourethrography in the 143 patients reveal ed new onset contralateral vesicoureteral reflux in 47 (33%). Mean tim e to the appearance of new onset reflux was 17.6 months (range 0.6 to 91.8). Reflux was grades I to III in 22, 21 and 4 patients, respective ly. Contralateral reflux resolved spontaneously in 19 cases (40%), per sists in an additional 16 (34%) and was surgically corrected at ipsila teral ureteroneocystostomy in the remaining 12 (26%). Contralateral re nal scarring was noted in 3 cases (6%). Conclusions: New onset contral ateral vesicoureteral reflux developed in a third of the patients init ially diagnosed with unilateral disease while they were followed nonop eratively. This finding suggests that contralateral reflux after the s urgical correction of unilateral disease may not always be associated with the surgical procedure. It may be a manifestation of the natural history of unilateral reflux.