Surgery for anal fistulae: state of the art

Abstract

Background and aim: Anal fistulae (AF) are considered a challenge for colorectal surgeons, as they recur if not properly operated. Being a septic disease, they are correlated with immunodeficiency and surgery may be followed by anal incontinence (AI). The aim of this paper is to suggest a state-of-the-art treatment of AF.

Methods: Pathogenesis, classification, diagnostic tools, intraoperative assessment, and surgeries proposed for AF have been reviewed, together with the results following conventional surgery and innovations aimed at sphincters' preservation.

Results: Stress causes immunodepression and favors anal sepsis, and heavy smoking facilitates AF recurrences. Evacuation fistulography, MRI, and transanal ultrasound may help the diagnosis. Fistulotomy allows high cure rate, up to 96.4%, but may cause up to 64% of AI in transsphincteric AF. Fistulectomy with rectal advancement flap is effective in 80% of these cases and avoids AI. Other options are either suturing of AF internal orifice or positioning a cutting seton. Ligation of intersphincteric fistula track (LIFT) is a costless alternative carrying a success of 57-99% with 0-23% AI. Costly innovations, i.e., autologous stem cells, porcine derma sheet (Permacol), video-assisted fistula excision (VAAFT), porcine matrix (PLUG), and laser closure (FiLaC), minimize AI, but may carry AF recurrence. Their grades of recommendation range between 2B and 2C in the Guidelines of the Italian Society of Colorectal Surgery.

Conclusion: Postoperative incontinence in transsphincteric AF may be minimized by both costless and costly sphincter-saving procedures, the latter carrying higher recurrence rate. The success of surgery may be increased by a different lifestyle.

Keywords: Anal fistulae; Anal incontinence; Fistulectomy; Fistulotomy; Innovations.