Development and characterization of a porcine experimental model for the evaluation of healing in perianal fistula as a platform for preclinical research.

Abstract

Anal fistula remains a therapeutic challenge due to the limited efficacy of current treatments. This limitation has prompted the development of animal models that replicate human anatomy and physiology to explore new therapeutic strategies. The pig has emerged as the reference preclinical model. In this study, Landrace-Large White pigs were used owing to their rapid growth, controllable weight, availability, and close anatomical similarity to humans. Three transsphincteric tracts were created per animal using 16-18 French Foley catheters with reinforced fixation, maintained for six weeks. Representative clinical and histological features were obtained. Four critical factors were identified to ensure model reproducibility: catheter calibre, fixation method, dwell time, and the interval between catheter removal and sacrifice. The optimized Landrace-Large White porcine model represents a robust translational platform for the preclinical evaluation of novel local therapies in anal fistula.