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

INTRODUCTION: 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. METHODS: 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] grades3 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. RESULTS: We included 169 patients (180 units). IH was diagnosed in 146 units (137patients), whereas 34 units (32 patients) had HUN. Median followup was 42.9 months. A total of 25.3% of IH units (37/146) 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<0.001). HUN had longer time till resolution (log rank=0.004). CONCLUSIONS: IH units had more initial surgical interventions. The FUTI rate was much higher in association with dilated ureter even under antibiotic coverage. HUN was associated with less and slower resolution rate.