A novel trauma induced urethral stricture in rat model.

Urethral stricture (US) is a longstanding disease, while there has not existed a suitable animal model to mimic the condition. We aimed to establish a trauma-induced US animal model to simulate this clinical scenario. A total of 30 rats were equally distributed into two groups, sham and US group. All rats were anesthetized with isoflurane and undergone cystostomy. In the US group, a 2 mm incision was made in the urethra and sutured to induce US. The sham group only make a skin incision on the ventral side of the anterior urethra. 4 weeks later, ultrasound and cystourethrography were performed to evaluate the degree of urethral stricture, pathological examinations were carried out to evaluate the degree of fibrosis. Urodynamic evaluation and mechanical tissue testing were performed to evaluate the bladder function and urethral tissue stiffness. The results showed that the urethral mucosa was disrupted and urethral lumen was stenosed in the US group. Additionally, the US group showed elevated bladder pressure, prolonged micturition intervals and increased tissue stiffness. In conclusion, the rat urethral stricture model induced by trauma provides a closer representation of the real clinical scenario. This model will significantly contribute to advancing research on the mechanisms underlying traumatic urethral stricture.