Incidence and natural history of contralateral vesicoureteral reflux in patients presenting with unilateral disease.

Abstract

The new onset of contralateral vesicoureteral reflux after the surgical correction of unilateral disease has been well documented and it is attributed to the surgical procedure. However, to our knowledge the spontaneous development of contralateral reflux in patients treated nonoperatively for unilateral disease has not been documented previously. We evaluated the incidence and natural history of contralateral reflux in children presenting with initially unilateral disease. We reviewed the records of 130 girls and 13 boys with a mean age of 29.1 months presenting with primary unilateral reflux between 1983 and 1996. The grade of and time to new onset contralateral reflux were noted. Whereas the initial radiological diagnosis relied on contrast voiding cystourethrography, followup evaluation included contrast and radionuclide voiding cystourethrography. The upper tracts were assessed by ultrasound and/or excretory urography, and cortical renal scans were performed selectively. Patients were followed 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 was associated with a ureteral duplication anomaly. At presentation reflux 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 revealed new onset contralateral vesicoureteral reflux in 47 (33%). Mean time 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, respectively. Contralateral reflux resolved spontaneously in 19 cases (40%), persists in an additional 16 (34%) and was surgically corrected at ipsilateral ureteroneocystostomy in the remaining 12 (26%). Contralateral renal scarring was noted in 3 cases (6%). New onset contralateral vesicoureteral reflux developed in a third of the patients initially diagnosed with unilateral disease while they were followed nonoperatively. This finding suggests that contralateral reflux after the surgical 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.