Modification of the sting procedure for vesicoureteral reflux: Ureteral repositioning and injection

OBJETIVE: Over the past 20 years endoscopic treatment (ET) of vesicoureteral reflux (VUR) has changed the algorithm of reflux management. We describe a modification of the standard subureteral injection (STING) that has contributed to the increased success rate of this procedure. METHODS: Between January 2006 and December 2006 192 children, 5 months to 10 years old (mean age 2.8 years) underwent endoscopic treatment for VUR, with injection of dextranomer/hyaluronic acid copolymer (Dx/HA). Standard STING procedure was used in 165 patients (235 ureters). A modified STING procedure, here described as "ureteral repositioning and injection" (URI) was used in 27 patients (38 ureters). In the URI technique, the needle was inserted as for standard STING; subsequently the distal part of the ureter was raised and levered towards the lumen of the bladder; Dx/HA was then injected. Renal/bladder ultrasound was performed 1 month after treatment and a voiding cystourethrogram (VCUG) at 4-6 months. RESULTS: After a single injection the VCUG showed no reflux in 203 ureters of STING group (86%) and in 34 ureters of URI group (91%). Mean injected volume of Dx/HA was 0.7 ml (0.3-1.8 ml) for STING and 0.4 ml (0.3-0.8 ml) for URI. CONCLUSION:The modified STING we have proposed, presents some advantages. It is very easy to perform and needs less material to inject. The ureteral repositioning into the bladder, with the support of the implanted material, may reconstruct a true flap-valve mechanism, without the risk of ureteral obstruction.