Significance: Benign Prostatic Hyperplasia (BPH) will become an increasing burden on economic resources with the aging population. Surgical treatment is well established and has provided satisfactory results in 60 - 80% of men. However, it has been associated with significant morbidity and risk of complications;therefore considerable efforts have been directed toward developing alternative minimally invasive treatments. Ablation of the prostate by direct injection has the potential to significantly reduce expense and morbidity;drugs are available to chemically ablate the tissue. However, though direct injection is a seemingly straightforward approach to the problem, backflow along the needle track and uneven distribution of drug after injection are significant drawbacks to chemoablation. In contrast to conventional injection needles, the hollow fiber delivery catheter is completely porous;therefore the surface area of tissue in contact with infusate is considerably increased. Hypothesis: We hypothesize that use of a hollow fiber catheter for direct infusion into the prostate will result in elimination of backflow and greater volume of distribution than the standard-of-care needle injection. Preliminary Data: We have demonstrated that the hollow fiber eliminates shear plane and reflux in a tissue phantom gel model, and increases the amount of adenoviral gene transfer by ten times in rodent models (relative to needle infusion). Specific Aims: This project entails preclinical testing of the hollow fiber catheter for eventual application to human patients with prostate disorders. In Specific Aim 1, we will construct and validate human-scale hollow fiber catheters that are suitable for use in dogs. A widely used clinical injection needle will be directly compared to hollow fiber for delivery of dye in a gel model and ex vivo dog prostates. Reflux of infusate and delivery distribution will be quantified along with catheter transmittance properties. In Specific Aim 2, we will use the validated catheters and compare to needles with in vivo injections into a dog prostate. An antibiotic, dye, and contrast solution will be infused and distribution will be determined by evaluation of reflux into bladder by assay (antibiotic), reflux along needle track by fluoroscopy (contrast) and prostate distribution by dye visualization (post procedure prostate removal and sections). Together, these studies will demonstrate the utility of hollow fiber catheters for prostate injections and accelerate the commercialization of hollow fiber for clinical use. PUBLIC HEALTH RELEVANCE: Drug delivery into the prostate represents a significant obstacle to achieving clinical efficacy. We have developed a novel "hollow fiber" catheter and shown its potential with preliminary studies as a direct injection method for the prostate. In this project, we will conduct preclinical feasibility testing of the hollow fiber catheter in dog prostates in preparation for clinical use of this technology in human patients.