Anal Fistula


Introduction

Anal fistula is characterized by an access between the anus and the perianal skin, usually caused by a slow infection of glands between the sphincters of the anus. There is no specific cause and it is not a hygiene problem. Sometimes the fistula comes after an anal abscess, which is a rapid accumulation of pus in an area of the anus or buttock close to the anus.

The usual symptoms of a fistula are suppuration, mild bleeding, anal itching, and pain (less often). The abscess is characterized by a lump and significant pain in a part of the anus.

The solution to this frequent pathology is always surgical. There are different procedures, whose indication depends on the morphology of the fistula, its relation to the anal musculature and the characteristics of the patient.



Treatment

The treatment depends on the type of fistula and patient.

Fistulotomy is the most effective procedure that guarantees the highest rate of healing and consists in cutting the skin, the part of the anal musculature that surrounds the fistula path and the fistula itself, leaving the wound open, which will heal spontaneously.

The most feared sequel of this surgery is anal incontinence so, when this risk is high and surgery cannot be performed safely, it is recommended to use to other less risky techniques that reduce or prevent injury to the anal sphincters.

Fistulotomy in two stages or two surgeries consists in sectioning the part of the fistula that does not pass through the anal sphincters, and placing a drainage in the area surrounded by musculature. After a few weeks or months of drainage, the fistula becomes more superficial and can be cut safely.

If the surgeon considers that the fistula is not superficial enough, another technique should be applied. There are filling techniques with biological material such as collagen, porcine dermis or plasma rich in fibrin and platelets that stimulate the progressive healing of the fistulous tract after scraping it.

The LIFT technique (Ligation of Intersphinteric Fistula Tract) consists in dissecting the fistula in the space that separates the two muscles of the anus, internal and external sphincters, ligating it in 2 points and sectioning it by the middle. Another surgery is the rectal advancement flap that involves the complete excision of the fistulous path covering the internal wound in the anus, left by the resection of the fistula, through part of the musculature and rectal mucosa.

A very new technique is the infiltration of autologous fat stem cells. Stem cells are cells able to multiply, resembling the tissue in which they are introduced: in this way, they help progressive scarring and the filling of the cavity produced by the anal fistula. Stem cells are obtained from the patient’s own fat by a small liposuction in an area of fat accumulation. If it is the own fat, there is no danger of rejection.

When the fistula is cut, it may affect the integrity and function of the anal musculature and cause faecal incontinence, the option of a sphincter conservative treatment such as collagen filling or biological plug should be considered, as well as the infiltration of autologous fat stem cells, or the complete fistulectomy with anus-rectal mucus-muscle flap advancement.

Not all techniques offer the same rate of success, but fistulotomy (fistula cutting) is the most effective. However, the big challenge of anal fistula surgery is to cure without leaving a serious sequel that is faecal incontinence. That is why there are many other safe techniques regarding incontinence, but none of them with the definitive result. This is why there are some patients who need more than one treatment to achieve healing.

In any case, a precise knowledge of the characteristics of the fistula through an exhaustive diagnostic evaluation, together with the experience of the proctologist surgeon, are the most important facts to have a successful and low-risk surgery. Other factors to take into account in the fistula surgery are the patient’s sex and age, the background of previous anal operations, the concomitance of other symptoms, such as mild incontinence or unknown injuries in the anal musculature secondary to childbirth.


Benefits

The treatment of anal fistula is necessary so as to eliminate the uncomfortable and smelly discharge from around the anus which, in addition to disturbing the patient himself, can interfere in intimate relationships. On the other hand, it should be considered that fistulas require early treatment since they can become abscesses or ramifications, which would make the symptoms worse, and damage the treatment result.



Expert opinion

Dr. Domenico Fraccalvieri
Dr.  Domenico Fraccalvieri

The purpose of all anal fistula surgeries is to achieve a healing process by controlling the infection and scarring the fistula path. When the fistula is not simple (superficial), two or more surgical proceudres may often be needed: the first one to control the infection and prevent the formation of other paths and the subsequent ones to achieve the complete healing.

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