Hyaluronic Acid Reduces Fibrosis in a Rabbit Model of Urethral Anastomosis

INTRODUCTION: Urethral stricture caused by fibrosis is a common medical condition, but top-line therapy for this pathology has a high recurrence rate. This study aimed to determine the efficacy of hyaluronic acid (HA) treatment in preventing the development of fibrosis in a rabbit model of urethral anastomosis. MATERIALS AND METHODS: This experimental study involved 20 rabbits. HA (0.5 mL, 25 μg/mL) was applied in the experimental group (n = 10) during an experimental urethral anastomosis, and sterile saline (0.9%) solution was applied in the control group (n = 10). Animals underwent reoperation 12 weeks later for urethral resection. Fibrosis, inflammation, and urethral diameter were measured by two blinded pathologists at the site of the anastomosis. RESULTS: The amount of inflammatory infiltrate was similar in both groups. The thicknesses of the collagen fiber band were 275.9 ± 62.3 and 373.4 ± 44.3 μm in the study and control groups (p = 0.001), respectively, and the urethral lumen diameters at the anastomosis site at follow-up were 2575 ± 167 and 2382 ± 214 μm, respectively (p = 0.04). CONCLUSION: HA treatment reduced fibrosis at the anastomosis site during this experiment; we suggest further research to corroborate its efficacy in the treatment of urethral stricture.