Objective To evaluate the degree of urothelial exposure using 3 upper tract delivery techniques in an ex vivo porcine model, to determine the optimal modality to locally deliver topical anticarcinogenic agents in patients with upper tract urothelial carcinoma. Materials and Methods An indigo carmine solution was infused into en bloc porcine urinary tracts to test the 3 techniques: antegrade infusion via nephrostomy tube, reflux via indwelling double-pigtail stent, and retrograde administration via a 5F open-ended ureteral catheter. Nine renal units (3 per delivery method) were used. After a 1-hour dwell time, the urinary tracts were bivalved and photographed. Each renal unit was evaluated by 3 blinded reviewers who estimated the total percentage of stained urothelial surface area using a computer-based area approximation system. In addition, as a surrogate for exposure adequacy, a validated equation was used to calculate the staining intensity at 6 predetermined locations in the upper tract, with lower values representing more efficient staining. Results Mean percent of surface area stained for the nephrostomy tube, double-pigtail stent, and open-ended ureteral catheter groups was 65.2%, 66.2%, and 83.6%, respectively (P =.002). Mean staining intensities were 40.9, 33.4, and 20.4, respectively (P =.023). Conclusion Our results suggest that retrograde infusion via open-ended 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 and potentially confirm this method as optimal for delivery of topical anticarcinogenic agents in upper tract urothelial carcinoma.
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