Background: Anal fistula is by definition the communication between the rectum or anal
canal with the perineal region, which may be epithelialized and has
cryptoglandular origin in 90% of cases. There are a large number of
techniques for successfully treating trans-sphincteric fistulas of 20-50%,
including primary sphincteroplasty, but it is not clear whether the material
used would influence the outcome. Aim: To analyze the efficacy of polydioxanone and polypropylene wire in primary
post-fistulotomy sphincteroplasty in the treatment of trans-sphincteric
fistulas in rats. Methods:Thirty Wistar rats had transfixation of the anal sphincter with steel wire,
which remained for 30 days for the development of the anal fistula. After
this period, it was removed and four groups were formed: A (control) without
treatment; B (fistulotomy) submitted to such procedure and curettage only; C
(polidioxanone) in which sphincteroplasty was performed after fistulotomy
with polydioxanone wire; D (polypropylene) submitted to the same treatment
as group C, but with polypropylene wire. After 30 days, euthanasia and
removal of the specimens were performed for qualitative histopathological
analysis, measurement of the area between the muscular cables edges and
evaluation of the degree of local fibrosis. Results: There was persistence of the anal fistula in all animals of group A. There
were no significant differences between groups B, C and D regarding the
distance of the muscular cables (p=0.078) and the degree of fibrosis caused
by the different treatments (p=0.373). Conclusions:There was no difference between polydioxanone and polypropylene wires in
post-fistulotomy primary sphincteroplasty, and this technique was not
superior to simple fistulotomy in relation to the distance of the muscular
cables nor did it present differences in relation to the degree of local
fibrosis.
Rationale
Fistulotomy followed by primary sphincteroplasty is one of the therapeutic options in transsphincteric fistulae; however, it was not known which suture would present a better result.
Objective
To compare polypropylene and polyglactin sutures in primary sphincteroplasty in rats subjected to fistulotomy.
Method
Thirty Wistar rats were subjected to peritoneal anesthesia with ketamine and xylazine, followed by transfixation of the anal sphincter with steel thread, which remained for 30 days to develop the anal fistula. After this period, the steel thread was removed and four groups were formed: A – Control (
n
= 5), without treatment; B – Fistulotomy (
n
= 5), performed fistulotomy only; C – Polypropylene (
n
= 10), in which fistulotomy was performed followed by primary sphincteroplasty with polypropylene suture; D – Polyglactin (
n
= 10), in which fistulotomy was performed followed by primary sphincteroplasty with polyglactin suture; after 30 days the animals were anesthetized again and submitted to euthanasia by deepening the anesthetic plane to remove the specimens, analyzing fistula closure, muscle fiber distance, and inflammatory process.
Results
The fistula persisted in all animals of the control group and in none of the other groups; the distances between the muscle fibers were 1620 μm, 4665 μm, and 2520 μm, respectively in Groups B, C, and D (
p
= 0.067); in relation to fibrosis, the means were 2.4, 2.8, and 3.6, respectively in Groups B, C, and D, showing greater fibrosis in the latter group (
p
= 0.041).
Conclusion
There was no persistence of the fistula in any of the treated animals; there was no difference in the distance between the muscle fibers between the groups subjected to primary sphincteroplasty with polypropylene or polyglactin, or between these groups and the one treated only by fistulotomy. There was greater fibrosis in animals treated with primary sphincteroplasty with polyglactin.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.