Does the presence of non-refluxing hydroureter impact the management and outcome of high-grade hydronephrosis?

We aimed to evaluate the impact of non-refluxing hydroureter on the initial management of high-grade hydronephrosis (HGH) management. Moreover, we evaluated the occurrence of febrile urinary tract infection (fUTI) and surgical intervention for conservatively managed units. Patients' charts with postnatal hydronephrosis from 2008-2014 were retrospectively reviewed. We included patients who presented in the first year of life. All included patients had HGH (Society of Fetal Ultrasound [SFU] grades 3 and 4) and all were non-refluxing using voiding cystourethrogram (VCUG). We categorized renal units into two groups: with hydroureteronephrosis (HUN) and without hydroureter (isolated hydronephrosis [IH]). We recorded the initial management. We evaluated the impact of non-refluxing hydroureter on hydronephrosis fate, fUTI, and change to surgery for those managed conservatively. We included 169 patients (180 units). IH was diagnosed in 146 units (137 patients), whereas 34 units (32 patients) had HUN. Median followup was 42.9 months. A total of 25.3% (37/146) of IH units had initial surgical management in comparison to 5.1% (2/34) of HUN units (p=0.01). During conservative management, nine HUN patients (30%) and 11 IH patients (10.7%) experienced fUTI (p=0.009). Surgical intervention after failed conservative management was indicated for 12 IH units (11%) and six HUN units (18.8%) (p=0.25). Anteroposterior diameter (APD) worsening was significantly associated with the change to surgery in IH group (p=0.003). More than half (52.3%) of IH units resolved during conservative management in comparison to 18.7% of HUN (p