Imaging Confirmation of Yo-Yo Reflux in Cases with Incomplete Ureteric Duplication

Background: Incomplete ureteric duplication can be associated with either ureteropelvic obstruction involving the lower moiety or reflux between the ureters (yo-yo reflux). Yo-yo reflux can be a cause of repeated urinary tract infection with subsequent renal damage. Aim of the work: The current study evaluated the presence of yo-yo reflux as reason of upper moiety dilation in cases with incomplete duplication of upper urinary tract. Methodology: 10 cases with a dilated upper moiety of duplex renal pelvicalyceal system were examined with color duplex ultrasonography. All were further investigated with intravenous pyelography (IVP), and ascending/micturating cystography. Results: 9 cases with upper moiety dilation showed complete duplication of the pelvicalyceal systems and ureters and 1 case with dilated upper moiety showed incomplete ureteric duplication in which the diagnosis of Yo-yo reflux was confirmed by color duplex ultrasound in addition to the intravenous pyelography findings. Conclusion: The presence of antegrade/retrograde flow within the dilated moiety of a duplex kidney during color duplex study in addition to the intravenous pyelography findings can confirm the diagnosis of yo-yo reflux.