Most anal fistulas are the result of an infection that starts in an anal gland. The infection causes an abscess that drains on its own or is drained surgically through the skin next to the anus. This drainage tunnel remains open and connects the infected anal gland or the anal canal to a hole in the outside skin around the anus.
Most anal fistulas are caused by an infection that starts in an anal gland. The infection results in an abscess that drains on its own or is drained surgically through the skin next to the anus. A fistula is the tunnel that forms under the skin along this drainage tract. The tunnel connects the anal gland or anal canal to a hole in the outside skin around the anus.
what causes anal fistulas
Anal fistulas occur most often in adults around the age of 40 but may occur in younger people, especially if there is a history of Crohn's disease. Anal fistulas occur more often in males than in females.
Your doctor can usually diagnose an anal fistula by examining the area around the anus. He or she will look for an opening (the fistula tract) on the skin. The doctor will then try to determine how deep the tract is, and the direction in which it is going. In many cases, there will be drainage from the external opening.
If a fistula is found, your physician may also want to do further tests to see if the condition is related to Crohn's disease, an inflammatory disease of the intestine. About 25% of people with Crohn's disease develop fistulas. Among these studies are blood tests, X-rays and colonoscopy. A colonoscopy is a procedure in which a flexible, lighted instrument is inserted into the colon via the anus. It is performed under conscious sedation, a type of light anesthetic.
Surgery is almost always necessary to cure an anal fistula. The surgery is performed by a colon and rectal surgeon. The goal of the surgery is a balance between getting rid of the fistula while protecting the anal sphincter muscles, which could cause incontinence if damaged.
Fistula surgery is usually done on an outpatient basis, which means the patient can go home the same day. Patients who have very large or deep fistula tunnels may have to stay in the hospital for a short time after the surgery. Some fistulas may require several operations to get rid of the fistula.
Most fistulas respond well to surgery. After the surgery, your surgeon may recommend that you soak the affected area in a warm bath, known as a sitz bath, and that you take stool softeners or laxatives for a week.
An anal fistula is an abnormal tunnel under the skin that connects the anal canal in the colon to the skin of the buttocks. Most anal fistulas form in reaction to an anal gland that has developed a pus-filled infection (abscess).
If you have symptoms that suggest an anal fistula, your healthcare provider may refer you to a specialist who specializes in colon and rectal diseases. The specialist will ask about your symptoms and your medical history. During your physical exam, the doctor will look for a fistula opening near your anal opening. He or she may press on the area to see if it is sore and if pus comes out. Different methods may be used to help with the diagnosis, such as:
Imaging studies. These may include an ultrasound, which creates an image of the anal area using sound waves. Or they may include an MRI, which makes images of the area by using special magnets and a computer.
Complications include a fistula that recurs after treatment and an inability to control bowel movements (fecal incontinence). This is most likely if some of the muscle around the anal opening, called the anal sphincter, is removed.
Call your healthcare provider if you have symptoms of an anal fistula, especially if you have a history of a previous anal abscess. If you have been treated for an abscess or fistula, let your provider know right away if you have any of the following:
An anal abscess is an infected cavity filled with pus found near the anus or rectum. Ninety percent of abscesses are the result of an acute infection in the internal glands of the anus. Occasionally, bacteria, fecal material or foreign matter can clog an anal gland and tunnel into the tissue around the anus or rectum, where it may then collect in a cavity called an abscess.
An anal fistula (also commonly called fistula-in-ano) is frequently the result of a previous or current anal abscess. This occurs in up to 40% of patients with abscesses. A fistula is an epithelialized tunnel that connects a clogged gland inside the anal canal to the outside skin.
Anal abscesses are classified by their location in relation to the structures comprising and surrounding the anus and rectum: perianal, ischioanal, intersphincteric and supralevator. The perianal area is the most common and the supralevator the least common. If any of these particular types of abscess spreads partially circumferentially around the anus or the rectum, it is termed a horseshoe abscess.
Fistulas are classified by their relationship to parts of the anal sphincter complex (the muscles that allow us to control our stool). They are classified as intersphincteric, transsphincteric, suprasphincteric and extrasphincteric. The intersphincteric is the most common and the extrasphincteric is the least common. These classifications are important in helping the surgeon make treatment decisions.
Anorectal pain, swelling, perianal cellulitis (redness of the skin) and fever are the most common symptoms of an abscess. Occasionally, rectal bleeding or urinary symptoms, such as trouble initiating a urinary stream or painful urination, may be present.
Patients with fistulas commonly have a history of a previously drained anal abscess. Anorectal pain, drainage from the perianal skin, irritation of the perianal skin, and sometimes rectal bleeding, can be presenting symptoms of a fistula-in-ano.
Up to 50% of the time after an abscess has been drained, a tunnel (fistula) may persist, connecting the infected anal gland to the external skin. This typically will involve some type of drainage from the external opening. If the opening on the skin heals when a fistula is present, a recurrent abscess may develop. Until the fistula is eliminated, many patients will have recurring cycles of pain, swelling and drainage, with intervening periods of apparent healing.
Treatment of complex anal fistulas is challenging as these fistulas tend to entail a significant portion of the anal sphincters, rendering complete eradication of the fistula tract associated with a considerable risk of continence impairment. On the other hand, failure to excise the primary tract and its secondary extensions and to drain sepsis adequately may eventually result in persistence or recurrence of the anal fistula[3].
It has been estimated that previous fistula surgery increases the odds of recurrence after further surgery by two to three folds[10,12]. While the exact cause of this observation is not clear, it may be explained by the disturbed anatomy of the perianal region after previous surgery and the effect of excess scarring and fibrosis which may render the identification of the internal opening, secondary branches, and associated abscess cavities technically challenging. This has been demonstrated in a recent study[19] on the utility of endoanal ultrasound (EAUS) in the assessment of recurrent anal fistulas compared to primary fistulas. The sensitivity of EAUS in the detection of the pathologic anatomy of recurrent fistulas was less than that of primary anal fistulas.
Clinical examination is then conducted to allow for inspection of the site of previous surgery and scar, detection of coexisting anal problems such as hemorrhoids or anal fissure, identification of the number and position of external opening(s), palpation of the tract from the external opening to the anal verge. Then, digital rectal examination (DRE) is followed to exclude anorectal lesions and assess anal tone. The identification of internal opening by DRE is usually difficult and not feasible. Finally, an office proctoscopy examination should conclude the examination. Complexity of recurrent anal fistulas can be suspected when the following signs are detected: More than one external openings, distant external opening away from the anal verge, anterior anal fistula in female, internal opening above the dentate line, and failure to palpate the whole tract from the external opening till the anal verge.
Afterwards, the surgeon should be able to assess the anatomy of the fistula tract in relation to the anal sphincters as inter-, trans-, supra-, or extra-sphincteric tract. The orientation of the tract should be also noted because a straight tract is different in management to a circumferential one as with horse-shoe fistula. Moreover, secondary extensions and branches of the main tract should be sought and either excised or curetted according to their anatomic location and extension.
If the recurrent anal fistula proved to be a simple intersphincteric fistula, then lay-open of the tract with curettage of its bed is usually sufficient, unless the risk of incontinence was high, then a sphincter-saving procedure such as LIFT should be attempted.
An anal fistula (also called fistula-in-ano) is a small tunnel that tracks from an opening inside the anal canal to an outside opening in the skin near the anus. An anal fistula often results from a previous or current anal abscess. As many as 50% of people with an abscess get a fistula. However, a fistula can also occur without an abscess.
A patient with an abscess may have pain, redness or swelling in the area around the anal area or canal. Other common signs include feeling ill or tired, fever and chills. Patients with fistulas have similar symptoms, as well as drainage from an opening near the anus. A fistula is suspected if these symptoms tend to keep coming back in the same area every few weeks.
Most anal abscesses or fistulas are diagnosed and managed based on clinical findings. Occasionally, imaging studies such as ultrasound, CT scan or MRI can help in the diagnosis and management of deeper abscesses and may be used to visualize the fistula tunnel. 2ff7e9595c
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