STING versus HIT technique of endoscopic treatment for vesicoureteral reflux: A systematic review and meta-analysis

Aim Our study aimed to compare the efficacy of two endoscopic techniques used for the correction of vesicoureteral reflux (VUR): subureteral transurethral injection (STING) and hydrodistension implantation technique (HIT). Methods A systematic review was conducted using MEDLINE, Google scholar, and Cochrane databases from 1984 to 2015. Meta-analysis of the selected studies was performed to compare the extent of reflux resolution following both techniques. Results Six observational studies met the inclusion criteria for content. These comprised 632 ureters treated by STING and 895 ureters treated by HIT procedure. All included studies utilized dextranomer/hyaluronic acid (Deflux) as the bulking agent. The overall resolution of VUR was significantly higher in HIT (82.5%) compared to STING (71.4%) [pooled odds ratio (OR)=0.54; 95% confidence interval (CI) 0.42–0.69; P 2 =8%]. A subgroup analysis showed that HIT had better outcomes than STING for both lower grade (I–III) [OR=0.43; 95% CI 0.23–0.82; P =0.01; I 2 =0%] and high-grade VUR (IV–V) [OR=0.43; 95% CI 0.20–0.91; P =0.03; I 2 =0%]. However, there was no statistical difference in the requirement of additional injections between STING and HIT groups. Conclusion HIT is superior to STING technique for resolution of VUR after Deflux injection. However, more randomized trials with longer follow-up are necessary to demonstrate the benefit of HIT compared to STING procedure. Level of evidence Retrospective comparative studies – level III.