Incidence of Deflux® calcification masquerading as distal ureteric calculi on ultrasound

Abstract Objective Dextranomer-hyaluronic acid (Deflux® ), the most widely used compound in the endoscopic treatment of vesico-ureteric reflux (VUR) today, is believed to provoke only minimal inflammation. Reports of calcification of Deflux® are increasing. We ascertain the incidence of Deflux® calcification appearing as distal ureteric calculi on ultrasound. Methods Three cases (2 external patients) of ureteroscopy for calcified submucosal Deflux® prompted a retrospective review of the notes and imaging of all children treated with Deflux® for VUR between December 2000 and January 2011 at Great Ormond Street Hospital. Results 232 children ( M : F = 5:3) received Deflux® for VUR at median age 2 years (range 2 months–12 years). Follow-up annual ultrasound, performed in all, identified calcification in 2. The interval between Deflux® injection and presentation of its calcification was 4 years. 104 of the 232 children had been followed up for 4–10 years. Considering the observed lag-period, after 4 years the incidence of calcification of Deflux® on ultrasound was 2% (2/104). Conclusions Patients should be warned that calcification of Deflux® can occur. Misinterpretation as ureteric stones is common and may lead to unnecessary ureteroscopy. In this series, the incidence of calcification of Deflux® on ultrasound after 4 years was 2%.