The natural history of pelvi-ureteric junction obstruction in children presenting clinically with the complaint.
OBJECTIVE: To determine the natural history of untreated pelvi-ureteric junction (PUJ) obstruction in children presenting clinically with the complaint. PATIENTS AND METHODS: The study comprised 42 children with anatomical PUJ obstruction (three with bilateral lesions) who were managed expectantly in the first instance, who had no immediately troublesome symptoms and differential function in the affected kidney(s) of > 40%. They were followed by serial ultrasonography and dynamic diuresis renography. Pyeloplasty was advised for those with persistent symptoms or where differential renal function fell below 40%. RESULTS: Only 15 children had presented with clearly relevant symptoms (loin pain or febrile urinary infection). Thirty-four kidneys showed obstructive renographic curves initially and 38 had moderate or severe hydronephrosis. During the follow-up (range 14-120 months, mean 56) patients remained asymptomatic except for four of the nine presenting with loin pain. Renographic curves were apt to change, with 'obstruction' increasing or decreasing with time, in the latter instance usually with lessening or resolution of hydronephrosis. Eleven patients underwent pyeloplasty, five for symptoms and six because of deteriorating renal function. Renal function did not decline in any patient with mild hydronephrosis and/or a non-obstructive renographic curve at presentation, but did so disproportionately in those with severe hydronephrosis or a Type IV renographic curve. CONCLUSIONS: Patients effectively asymptomatic at presentation are likely to remain so. Expectant management is appropriate for patients with mild hydronephrosis and/or non-obstructive renographic curves at the outset. Conversely, pyeloplasty may be advisable for those with severe hydronephrosis or Type IV renographic curves. Otherwise, for most the natural history of the complaint remains to be determined.