696 WHAT IS THE BEST METHOD TO DELIVER ADJUVANT THERAPY TO THE UPPER URINARY TRACT FOR UROTHELIAL CARCINOMA? EVALUATION OF THREE TECHNIQUES USING AN EX-VIVO PORCINE MODEL COMPARISON

Abstract

INTRODUCTION AND OBJECTIVES: Endoscopic management of upper tract urothelial tumors often includes the delivery of adjuvant therapy to the upper tract to reduce ipsilateral recurrences. Three main delivery techniques have been described: antegrade infusion via nephrostomy tube, reflux via indwelling double pigtail stent, and retrograde administration via an open-ended ureteral catheter. However, no publications to date have compared the efficacy of the three delivery methods. We developed an ex-vivo porcine model to evaluate the degree of urothelial exposure using each technique. METHODS: An indigo-carmine solution was infused into enbloc porcine urinary tracts to test the three techniques; 9 renal units were used. Efforts were made to mimic the positioning of a supine human patient receiving treatment. Following a 1 hour dwell time, the urinary tracts were bivalved and photographed. A validated equation (CIE76) was used to calculate the staining intensity at 6 different locations in the upper tract. Additionally, each renal unit was evaluated by 3 blinded reviewers who estimated total percentage of stained surface area. ANOVA and multivariable analyses were conducted to explore variability between reviewers. RESULTS: Mean staining intensities (lower values represent greater staining) for the nephrostomy tube, double pigtail stent, and open-ended ureteral catheter groups were 40.9, 33.4, and 20.4, respectively (p 0.023). Mean percent of surface area stained was 65.2%, 66.2%, and 83.6%, respectively (p 0.002). CONCLUSIONS: Our results suggest that retrograde infusion via ureteral catheter is the most efficient method of upper tract therapy delivery. Larger studies using in-vivo models should be performed to further validate these findings. Comparison of intensity and surface area staining using post-hoc analysis.