Experimental model of anal fistula in rats

Abstract

Introduction the management of anal fistula remains debatable. The lack of a standard treatment free of complications stimulates the development of new options. Objective to develop an experimental model of anal fistula in rats. Methods to surgically create an anal fistula in 10 rats with Seton introduced through the anal sphincter musculature.The animals were euthanized for histological fistula tract assessment. Results all ten specimens histologically assessed had a lumen and surrounding granulation tissue. There was complete epithelialization of the tract in two samples, halfway epithelialization in one sample and epithelialization of only the outer portion in six samples. Epithelialization was not evident in one tract. Conclusion anal fistulas in rats were histologically proved.

Review article: pathogenesis of Crohn's perianal fistula—understanding factors impacting on success and failure of treatment strategies

“…A steel wire through the anal sphincter from perineum to anus was used to create a model of anal fistula in 10 rats . After 30 days, the ano‐perineum was excised and sectioned to prove that a fistula track had been established.…”

“…Furthermore, the presence of a foreign body through a fistula (such as a loose seton placed for drainage) is likely to stimulate epithelialisation. Again, this has not been studied to our knowledge (except in animal models), but surgical experience will prompt the reader to recognise this situation. Setons are useful to reduce inflammation and perhaps allow secondary tracks to drain and heal, in the hope of rationalising a complex fistula into a nonbranching, simpler track.…”

“…Furthermore, the presence of a foreign body through a fistula (such as a loose seton placed for drainage) is likely to stimulate epithelialisation. Again, this has not been studied to our knowledge (except in animal models 56…”

“…A steel wire through the anal sphincter from perineum to anus was used to create a model of anal fistula in 10 rats. 56 After 30 days, the ano-perineum was excised and sectioned to prove that a fistula track had been established. In 2 rats the track was fully epithelialised, in another around half the track was epithelialised and in 6 there was some epithelialisation at the outer portion of the track.…”

Tratamento da fístula anal com extrato de Baccharis dracunculifolia. Estudo experimental em ratos.

“…in relation to other herbal medicines, its extract seems to have great therapeutic potential. This is because it is believed that anal fistula represents the chronic phase of cryptoglandular abscess and, thus, local control of inflammation could be useful for its treatment 5 . invasive of agricultural areas and pastures 15 , has already been determined by several authors [16][17][18] .…”