An experimental model for stricture studies in the anterior urethra of the male rabbit

In this study, an animal model was developed for the examination of urethral strictures (US). Through a resectoscope, a resection was made in the urethras of 15 male rabbits. After 30 days, the rabbits were evaluated with urethrography, impedance planimetry and either histology or the determination of collagen content. Fifteen rabbits serving as controls were evaluated in the same way. Three rabbits in the resection group and one in the control group died before evaluation. Urethrography demonstrated a stricture in the remaining 12 animals in the resection group. The urethras of the control animals were all normal. Impedance planimetry confirmed that the luminal cross sectional area (CSA) of the strictures was significantly smaller than the CSA of the corresponding part of the urethra in the control group. No difference in CSA was found 1 cm proximal to the stricture. The strictures consisted of densely woven collagen which sent tongues into the adjacent normal parts of the urethra. No difference in collagen content was found between the two groups either at the stricture site or 1 cm proximally. The described method of producing US in the rabbit model was very consistent with all operated animals developing a stricture. The model might prove valuable in evaluating new methods for the treatment of US.