Development of a rat model for investigation of experimental splinted uretero-ureterostomy, ureteral stenting and stenosis.

BACKGROUND AND AIM: The objective of this study was to establish a rat model to develop hypertrophic fibrosis for subsequent safe application of ureteral stents in order to investigate new treatment options for ureteral strictures.

MATERIALS AND METHODS: Thirty-two male Sprague-Dawley rats were used. Group 1: Sham surgery; group 2: surgery with uretero-ureteral anastomosis and stenting. Histopathological evaluation was carried out using 5-bromo-2-deoxyuridine administration before the animals were sacrificed.

RESULTS: A total of thirty-one animals reached the final end-point. The most common surgical complications were urine extravasation and stent dislocations. Histological examination showed full regeneration of urothelium after 28 days and development of a scarring process. With stent insertion, moderate hypertrophia was seen. In contrast, the sham group had no evidence of significant scarring or stricture formations.

CONCLUSION: Our rat model allows for investigation of the wound healing processes of urothelium of the ureteral wall and the study of the application of new miniature stents as drainage and drug carriers.