PRIMARY OBSTRUCTIVE MEGAURETER WITHOUT RE FLUX IN NEONATES

Routine prenatal ultrasonography has had a major impact on the diagnos is of megaureter. Pediatric urologists are seeing increasing numbers o f neonates with asymptomatic megaureters. In addition, there have been a fairly large number of reports of spontaneous resolution of primary megaureter without reflux. Fifty-nine primary megaureters with obstru ction but no reflux were seen in 48 neonates. Primary megaureter witho ut reflux may be responsible for nonnegligible obstruction in patients with evidence of stasis and noticeable pyelocalyceal dilatation. Cons equently, immediate surgery was performed for 35 of the megaureters. A mong the 24 cases initially managed by watchful waiting, 11 required s urgery seven to 29 months after the diagnosis because the dilatation w as either stable (n = 6) or progressive (n = 5), of the 13 untreated m egaureters, seven resolved completely and six partially with persisten ce of minimal pelvic dilatation. Early or delayed reimplantation yield ed excellent results (with one case of postoperative necrosis successf ully treated by surgery, one reoperation for reimplantation, and two p ersistent minor dilatations). Relief of obstruction without reflux was achieved in 92% of cases. The relative value of available methods for assessing ureteral obstruction and renal function in neonates is uncl ear. In this series, immediate surgery was performed when the intraven ous urogram showed delayed secretion of the contrast agent, massive di latation, and delayed drainage of the collecting system into the bladd er. Although this strategy is open to debate, it is at least as reason able as postponing surgery until the development of renal failure.