A Novel Modification of the Endorectal Advancement Flap for Complex Anal Fistulas: Surgical Technique and Outcomes

Abstract

Objective A modification of the endorectal advancement flap (EAF) procedure is described with outcomes in a single-center, large retrospective cohort study. Summary of background data Fistula-in-ano is a common problem encountered by surgeons that can be classified as either simple or complex. Complex fistulas (CFs) cause higher morbidity and are much more challenging to treat. Although numerous treatment options are available for CF, none are proven to be 100% effective. The endorectal advancement flap (EAF) procedure was developed as an alternative to conventional surgical treatments for CF. Methods Charts were reviewed of patients with CF who underwent EAF between 2004 and 2019. The conventional EAF procedure was modified by performing transverse imbrication of the internal sphincter over the internal fistula opening. The incidence of new-onset fecal incontinence and recurrence were analyzed at the last available date of in-person follow-up. Results With a median follow-up of 6.6 months (range, 3.3–24 months), 99 patients with CFs underwent a modified EAF. Of these, 93% (92 of 99) had resolution of fistula without adverse outcomes, 7% (7 of 99) experienced recurrence, and 1% (1 of 99) experienced new-onset fecal incontinence. Systemic steroid or immunomodulatory therapy use (P = 0.001) and patients with diagnosed inflammatory bowel disease (P < 0.0001) were associated with increased rate of recurrence. Conclusions EAF with transverse imbrication of the internal opening using interrupted, absorbable suture is an effective technique to treat complex or recurrent anal fistulas. It is associated with a low risk of recurrence (7%) and fecal incontinence (1%) and is a valid treatment option for CFs.