Surgery for anal fistula: laser fistulectomy vs. sphincter-sparing procedures

The dilemma between realistic chances of healing and the desire for gentle treatment

At our proctology centre in Munich, we also treat anal fistulas. Unfortunately, healing the fistula without surgery is not possible. All hopes of healing an anal fistula through medication or special wound care measures have not been fulfilled.

In the specific case of fistulas in patients with inflammatory bowel disease, novel forms of treatment with antibodies and long-term antibiotic therapy can achieve some symptom control. Long-term drainage with silicone thread drains reduces pain by preventing the development of abscesses.

A barely active fistula that causes the patient only little discomfort can possibly be left without treatment. We discuss this option with each patient individually.

Our standard: excision of the anal fistula with laser (fistulectomy)

In many cases, the course of the fistula is relatively superficial, which makes the risk of restricting the ability to hold stool (continence) when the fistula tract is peeled off appear reasonably low. The wound is left open. The chances of healing are over 90 %. The price for this can be a protracted healing process lasting months. In most cases, the patient is only unable to work for 2-3 weeks. Slight disturbances of the sphincter function (shortening of the warning time, restriction of the ability to hold air and liquid stool, stool smearing) cannot be completely ruled out, but are usually not of significant extent. This may make some patients shy away from such an operation. On the other hand, it must be taken into account that the chronic inflammation caused by the anal fistula can also attack the sphincter muscle in the long term or worsen its function through scarred hardening.

We always perform anal fistula peeling with the laser (Intros Lina 980 nm, Biolitec Ceralas 15 1470 nm) and with the aid of magnifying glasses (laser fistulectomy). A particularly bloodless operation with optimal assessment of all details, especially the identification of the fistula origin, which is otherwise sometimes difficult to find, is almost always possible with laser fistulectomy. The probability of relapses (recurrences) can thus be kept low. Healing sets in somewhat faster than with surgery without laser, and the scars become smooth and elastic.

This surgical technique is the only procedure we offer in our practice. If there are medical or personal concerns about the functional outcome of the fistulectomy, we will be happy to advise you on alternative techniques and refer you to a surgeon or clinic experienced in the technique.

Alternatives: sphincter-sparing surgical procedures for anal fistula

There are numerous strategies to remove an anal fistula without compromising faecal continence. New surgical techniques are constantly being developed. Currently, none of these methods is fully satisfactory in every respect, with published cure rates ranging from 0 to 80 per cent.

Anal fistula laser surgery (FiLaC)

This technique attempts to gently remove the anal fistula by using laser energy. The flexible, all-round radiating fibre-optic probe is inserted into the fistula tract from the outside. Then the laser is slowly withdrawn. The inflammatory tissue is destroyed in a controlled manner and the fistula tract contracts. The anal gland that originally caused the fistula is inactivated.

This concept seemed very promising when it was introduced about ten years ago and has been used again and again in selected cases. Unfortunately, it had to be learned that the "welding" of the inner fistula opening by laser is not possible as hoped. Even the additional suture closure or application of a displacement flap did not reproducibly improve the treatment results. The healing rates of up to 80 % described in the literature seem to me to be clearly too optimistic. In addition, the FiLaC technique requires that the fistula tract can be probed with the fibre-optic probe at all, so that in some cases the method cannot even be used from a technical point of view.

I have therefore decided to no longer offer the FiLaC technique.

Closure of an anal fistula by biological implants (fistula plug)

The fistula tract is not cut out, but simply freed from inflammatory tissue with a special brush. A conical implant with a circular anchoring plate made of collagen or a synthetic soluble material is then pulled through from the inside to the outside. The fistula tract is now filled with the implant. The anchoring plate is fixed to the sphincter muscle with seams.

The first studies spoke of cure rates of up to 80 percent. Unfortunately, these hopes have not been confirmed either. Further studies found success rates of only < 20 per cent in some cases. Most proctologists no longer use this procedure. Some manufacturers of such materials have also stopped producing the implants.

I therefore no longer use the plug technique.

Anal fistula - treatment: The loose thread drainage (silicone drainage) as a permanent solution

Since ancient times the technique of a thread pulled through the anal fistula has been described, which is gradually tightened more tightly. The hope of severing the sphincter muscle in small steps and allowing the tissue behind the thread to heal immediately is not fulfilled in practice. Apart from that, the "cutting thread" is a painful procedure and should no longer be used. Good experiences with a thread impregnated with plant extracts (Ayurveda thread) have been reported from India. Details of the procedure and the composition of the thread coating were not disclosed. Therefore, other doctors could not gain any experience with this technique.

The loose thread drainage, which works with a thin silicone tube, offers the possibility to heal an acute inflammation up to a definitive operation. A thread drainage can also be useful if you are not sure about the optimal treatment of the anal fistula due to massive swelling of the tissue. In difficult cases, such as chronic inflammatory bowel diseases such as Crohn's disease, thread drainage can also be a permanent solution. The fistula does not heal, but adhesion and abscess formation are avoided.

Intersphincteric ligation (Ligation of Intersphincteric Tract, LIFT technique)

This procedure aims to close the fistula tract in the area where it crosses the separating layer between the internal and external sphincter. The sphincter muscle is not cut in the process. The advantages are a comparatively small, arch-shaped incision at the anal verge and the suture in an area where a passage of stool does not disturb the healing every day. A good address for this technique is the Clinic for Visceral Surgery at the Bogenhausen Clinic.

Anal fistula cleavage with primary reconstruction

The fistula is split to allow optimal access to the entire fistula tract. The fistula tract is then completely removed and the severed sphincter portion reconstructed with sutures. Experienced surgeons report high healing rates of up to 90 per cent. However, this relies on the healing of sutures in an unfavourable area. The healing process is often long and drawn out over months. It is not uncommon for sutures to come loose again prematurely. Nevertheless, the functional result is usually good.

In difficult cases where large parts of the sphincter muscle are affected, a temporary artificial outlet (anus praeter) is sometimes necessary to improve the chances of healing, which is then closed again after the anal fistula has healed. In summary, this option is a stressful therapy procedure due to several interventions, hospital stays and a long healing process. If we recommend this therapy modality to you, we will refer you to an appropriately experienced centre, in Munich, for example, to the Department of Anal and Rectal Surgery at the Neuperlach Clinic.

Plastic surgery procedures

In particularly difficult cases, anal fistulas form all the way to the vagina (ano-vaginal or recto-vaginal fistula). The layer between the rectum and the vagina is very delicate, so that there is little "material" to close the opening. Therefore, one usually needs to use the body's own tissue, for example muscle-fat tissue from the perineum or from the leg (gracilis flap). Biomaterials of animal origin are also used in this situation. Almost always, the creation of an artificial outlet is necessary to protect the reconstruction so that defecation does not lead to infection of the repaired tissue.