Management of primary non-refluxing upper urinary tract dilation: an analysis of 219 pediatric patients

Antenatal ultrasound (US) examinations have changed the diagnostic approach to and management of malformative uropathies. Primary non-refluxing upper urinary tract (UUT) dilation is one of the urinary malformations that has undergone significant evolution in recent years. From January 1972 to June 1991, 219 children with primary non-refluxing megaureter (caliber more than 10 mm on radiologic examination) were admitted to our pediatric surgical department; 37 (16.8%) had bilateral UUT dilatation, an overall 256 renal units. The patients were divided into two groups: from January 1972 to June 1985 and from July 1985 to June 1991. In the latter period there was a considerable and progressive increase in admissions of infants in whom a prenatal US diagnosis of UUT dilation was made. A total of 186 renal units in 166 patients were operated upon; the success rate was 92%. A total of 70 megaureters (17 bilateral) in 53 patients were managed conservatively. The percentage of conservatively managed cases has increased in recent years; in almost all these patients the diagnosis was made antenatally. Our criteria for conservative management have been absence of obstruction and normal renal function as assessed by dynamic diuretic DTPA renography. These patients were carefully followed by serial US examinations and diuretic DTPA renograms. The follow-up of these 53 patients ranged from 6 months to 16 years with an average of 3 years 6 months; 47 have had a minimum follow-up of 18 months. In all these patients there has been progressive, spontaneous reduction or normalization of the dilation and no deterioration of renal function. In the authors opinion less than 50% of infants with grossly dilated non-refluxing megaureter diagnosed prenatally should be considered candidates for surgery, while the majority can be successfully managed without surgery.