Long-term followup of primary nonrefluxing megaureter

Abstract

Purpose: We evaluated outcomes of nonoperative management of primary nonrefluxing megaureter at long-term followup to identify clinical predictors of spontaneous resolution.

Materials and methods: A total of 75 patients (88 primary megaureters) were diagnosed between 1990 and 2005 and followed for more than 6 months. Of the patients 63 (74 primary megaureters) were included in the main study population. Indications for surgery were obstructive hydroureteronephrosis, functional impairment and persistent symptoms.

Results: Of the 74 primary megaureters 20 (27%) required surgery up to 7 years after diagnosis. Surgery was not indicated in 82% of primary megaureters with grade I or II hydronephrosis vs 62.9% of those with grade III or higher hydronephrosis (difference not significant), nor in 76.5% of types I and II primary megaureters vs 33.3% of type III primary megaureters (p = 0.040), 78.7% of renal units with differential function 40% or greater vs 0% with differential function less than 40% (p = 0.027), 80% of primary megaureters with a nonobstructive washout pattern vs 44.4% with an intermediate/obstructive pattern (p = 0.032), 67.9% of patients with perinatal presentation vs 25% with postneonatal presentation (p = 0.008) or 63.2% of patients presenting with symptoms vs 76.4% of those who were asymptomatic (difference not significant). On multivariate analysis age at presentation and washout pattern were significant predictors of spontaneous resolution.

Conclusions: Most cases of primary megaureter resolve spontaneously or improve without loss of function or development of symptoms. Careful observation allows surgery to be delayed beyond the neonatal period in most patients. Long-term followup is recommended because symptoms can develop years later. Washout pattern and age at presentation are statistically significant predictors of spontaneous resolution.

Keywords: PM; ROI; US; hydronephrosis; primary megaureter; region of interest; ultrasonography; ureter; ureteral obstruction; urologic diseases.