Conventional cutting vs. internalanal sphincter-preserving seton for high trans-sphinctericfistula: a prospective randomized manometric and clinicaltrial

Abstract. Background: Cutting setons have been used in complicated perirectalsepsis with good effect, although there is a moderately highincidence of fecal leakage after their use. The aim of thisstudy was to compare a modified cutting seton, which repairedthe internal anal sphincter muscle and re-routed the setonthrough the intersphincteric space, with a conventional cuttingseton. Methods: A total of 34 patients were randomized between 1998 and2002. They were prospectively assessed by continence score andanorectal manometry, and for anal function, clinical sepsis andfistula recurrence. Results: There was no difference in postoperative continence score,incidence of recurrent fistula or healing time between groupsafter a mean follow-up of 12 months. Resting anal manometricpressures and vector volumes were consistently higher with themodified seton (although not statistically significant), as wasthe area under the inhibitory curve during elicitation of therectoanal inhibitory reflex across the full sphincter length.(p<0.05). Conclusion: A larger prospective study of internal analsphincter-preserving seton use in cryptogenic hightransshincteric fistula-in-ano appears justified.