Sphincter Preserving Techniques in Anal Fistula Treatment

*Dorian Kršul, Damir Karlović, Đordano Bačić and Marko Zelić*

### **Abstract**

Complex anal fistulas present a challenge to even a seasoned colorectal surgeon due to high rate of recurrence and a real possibility of fecal incontinence if treated with conventional methods (e.g., fistulotomy, fistulectomy, seton placement). Although the illness is benign in nature, it can significantly decrease patient's quality of life because of symptoms like pain and soiling. Given those facts, minimally invasive or sphincter preserving methods of treatment were introduced. Some of these include: Video-assisted anal fistula treatment (VAAFT), ligation of intersphincteric fistula tract (LIFT), Fistula-tract laser closure (FILAC), rectal advancement flap (RAF), treatment with platelet cells and combinations of techniques. This chapter would be an overview of these novel techniques with reference to latest clinical trials and meta-analyses.

**Keywords:** VAAFT, LIFT, RAF, FiLaC, anal fistula, sphincter preserving, proctology

#### **1. Introduction**

Anal fistula is a chronic abnormal connection between the anal canal and the perianal skin. It is a tract lined with granulation tissue which supports chronic inflammation. Incidence of the disease is about 10 cases per 100 000 individuals with male to female ratio of 2:1. It mostly develops after an abscess of cryptoglandular origin although it can be associated with inflammatory bowel disease (IBD), trauma and carcinomas [1, 2].

Various classifications are proposed, but most widely used is the Parks classification. It relates to the course of fistula in relation to the sphincter mechanism [3]. Nowadays, fistulas can also be classified as simple and complex according to the relation of the proportion of the anal sphincter mechanism they pass through. Simple anal fistulas have one tract that crosses less than 30% of the external anal sphincter. They are treated best by fistulotomy or fistulectomy with very low incidence of continence disturbance. Other fistulas are classified as complex. These tracts cross external anal sphincter at a point that involves more than 30% of the external anal sphincter and can be associated with multiple tracts. Complex fistulas also include those anteriorly positioned in a female, recurrent fistulas and those related to IBD. In case they are treated by lay-open techniques, there is a high risk of postoperative continence disturbance [4].

The average rate of continence disturbance following treatment with a cutting seton is up to 12% which increased when the internal opening of fistula tract was

positioned more proximally [5]. Following lay open techniques, the incidence of flatus incontinence or liquid stool leakage was observed in 20–25% of the patients [6]. This effect on continence has resulted in these techniques being less favorable for complex anal fistulas and the appetite for the use of minimally invasive techniques is increasing.

Various sphincter preserving techniques were introduced in clinical practice in the last 10–15 years with different success rates. This chapter serves as an overview of these techniques. This chapter covers treatment of cryptoglandular anal fistula. Anal fistula associated with Crohn's disease present a somewhat different problem and are not the scope of this chapter.

It is important to note that, given the novelty of some of these techniques, exact indications and contraindications do not exist as such. There are, however, some recommendations made in publications concerning various respective techniques, and these are referred to in the reference section. Authors of this chapter, given our experience in using these novel techniques, will fill in the gaps that may exist, extrapolated from our clinical practice.
