A Comparison of Calcium Hydroxyapatite and Dextranomer/Hyaluronic Acid for the Endoscopic Treatment of Vesicoureteral Reflux

Purpose. Minimal data exists comparing dextranomer/hyaluronic acid (Dx/HA) and calcium hydroxyapatite (CaHA) for the endoscopic treatment of VUR in the hands of a single user. Materials and Methods. We reviewed our consecutive single-user case series of 27 children (42 ureters) receiving endoscopic treatment with CaHA and 21 children (33 ureters) who received Dx/HA injection. Children receiving CaHA injections were divided into two groups of 13 and 14 patients (Coaptite I and II) to assess the learning curve effects. Postoperatively, RBUS and VCUG were performed. Multiple regression analysis was performed to assess statistical significance of success rates. Results. The total CaHA group had a per-ureter success rate (Grade 0) of 52% after one injection. When separated into two cohorts, the single injection per-ureter success rates were 43% for Coaptite I and 62% for Coaptite II. In contrast, the Dx/HA series had a single injection per-ureter success rate (Grade 0) of 78%. Conclusions. Our consecutive case experience shows improved results for Dx/HA compared to CaHA, though the learning curve effects and evolution of injection technique likely played a role in the improved outcomes in the Dx/HA cohort. A randomized controlled multicenter trial would provide the most accurate data comparing these two agents. 1. Introduction Recent years have seen a dramatic rise in the endoscopic treatment of vesicoureteral reflux (VUR) as an alternative to traditional ureteral reimplantation and antibiotic therapy [1, 2]. Prior to 2001, endoscopic therapy in the United States was limited to primarily off-label use of a variety of injectables, including polytetrafluoroethylene (Teflon) and polydimethylsiloxane (Macroplastique) which showed efficacy of >70% in clinical trials. They were later shown to have possible migration risks and never received FDA approval [3]. Subsequently, attention was turned toward larger-sized molecules (greater than 65？μm in size), including calcium hydroxyapatite (CaHA, Coaptite) and dextranomer/hyaluronic acid (Dx/HA, Deflux). CaHA is a 100？μm synthetic particle with a chemical composition identical to bone and teeth. The spherical molecules are delivered in an aqueous-based gel carrier. It has been widely used in the United States in dentistry, orthopedic surgery, plastic surgery, and ear, nose, and throat surgery. Coaptite was approved in 2005 for urologic use in the treatment of stress urinary incontinence [4]. Animal studies on calcium hydroxylapatite have shown it to be biocompatible with no associated migration risk. In contrast to