Experimental model of perianal fistula in a small laboratory animal

Abstract

Perianal fistula is a common disease usually requiring surgical interventions. New alternative therapeutic methods (stem cells transplantation, fibrin glue, fistula plug) are currently investigated. A suitable animal model is needed to evaluate the effect of these techniques in an experimental study. The aim of this study was to create a clinically adequate model of perianal fistula applicable in the evaluation of new therapeutic methods.

Methods: Axial caecostomy with 2.5 cm subcutaneous channel was performed in 30 Wistar rats. After the 40-day follow-up, the animals were randomized into three groups. The first group was treated with suture to the fistula opening the second group by fistula tract ligation, and the third was a control group without intervention.

Results: The model was technically feasible in all animals with an average operating time 22 (± 5.1) mins. During the 40-day observation two animals (7%) died on the first and fifth postoperative day, and one animal (3%) had spontaneous fistula healing. In total, 27 animals were randomized. In groups with opening suture (n = 9), tract ligation (n = 12) and in control group (n = 8) fistula healing was observed in three (33%), six (50%) and 0 (0%) animals. Results in interventional groups were in agreement with results of clinical trials.

Conclusion: A clinically adequate model of perianal fistulas suitable for the evaluation of new treatment techniques was created.