Anal fistula | |
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Other names | Anal fistulae, fistula-in-ano |
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Different types of anal fistula | |
Specialty | General surgery |
Anal fistula is a chronic abnormal communication between the anal canal and the perianal skin. [1] An anal fistula can be described as a narrow tunnel with its internal opening in the anal canal and its external opening in the skin near the anus. [2] Anal fistulae commonly occur in people with a history of anal abscesses. They can form when anal abscesses do not heal properly. [3]
Anal fistulae originate from the anal glands, which are located between the internal and external anal sphincter and drain into the anal canal. [4] If the outlet of these glands becomes blocked, an abscess can form which can eventually extend to the skin surface. The tract formed by this process is a fistula. [5]
Abscesses can recur if the fistula seals over, allowing the accumulation of pus. It can then extend to the surface again – repeating the process. [5]
Anal fistulae per se do not generally harm, but can be very painful, and can be irritating because of the drainage of pus (it is also possible for formed stools to be passed through the fistula). Additionally, recurrent abscesses may lead to significant short term morbidity from pain and, importantly, create a starting point for systemic infection. [5]
Treatment, in the form of surgery, is considered essential to allow drainage and prevent infection. Repair of the fistula itself is considered an elective procedure which many patients opt for due to the discomfort and inconvenience associated with an actively draining fistula. [5] [3]
Anal fistulae can present with the following symptoms: [4]
Diagnosis is by examination, either in an outpatient setting or under anaesthesia (referred to as EUA or Examination Under Anaesthesia). The fistula may be explored by using a fistula probe (a narrow instrument). In this way, it may be possible to find both openings. The examination can be an anoscopy. Diagnosis may be aided by performing a fistulogram, proctoscopy and/or sigmoidoscopy. Possible findings:
Depending on their relationship with the internal and external sphincter muscles, fistulae are classified into five types:
Other conditions in which infected perianal "holes" or openings may include pilonidal cyst.
There are several stages to treating an anal fistula:
Definitive treatment of a fistula aims to stop it recurring. Treatment depends on where the fistula lies, and which parts of the internal and external anal sphincters it crosses. However, treatment is challenging as complete eradication of the anal sphincters may lead to continence impairment, but failure to excise the affected areas results in recurrence. Those already treated for recurring anal fistula are at higher risk to experience re-recurrence of the disease.
The VAAFT procedure is done in two phases, diagnostic and operative. Before the procedure, the patient is given a spinal or general anaesthetic and is placed in the lithotomy position (legs in stirrups with the perineum at the edge of the table). In the diagnostic phase, the fistuloscope is inserted into the fistula to locate the internal opening in the anus and to identify any secondary tracts or abscess cavities. The anal canal is held open using a speculum and irrigation solution is used to give a clear view of the fistula tract. Light from the fistuloscope can be seen from inside the anal canal at the location of the internal opening of the fistula, which helps to locate the internal opening. In the operative phase of the procedure, the fistula tract is cleaned and the internal opening of the fistula is sealed. To do this, the surgeon uses the unipolar electrode, under video guidance, to cauterise material in the fistula tract. Necrotic material is removed at the same time using the fistula brush and forceps, as well as by continuous irrigation. The surgeon then closes the internal opening from inside the anal canal using stitches and staples.
Some people will have an active infection when they present with a fistula, and this requires clearing up before definitive treatment can be decided.
Antibiotics can be used as with other infections, but the best way of healing infection is to prevent the buildup of pus in the fistula, which leads to abscess formation. This can be done with a seton.
A literature review published in 2018 showed an incidence as high as 21 people per 100,000. "Anal fistulas are 2–6 times more prevalent in males than females, with the condition occurring most frequently in patients in their 30s and 40s." [20]
The perineum in mammals is the space between the anus and the genitals. The human perineum is between the anus and scrotum in the male or between the anus and vulva in the female. The perineum is the region of the body between the pubic symphysis and the coccyx, including the perineal body and surrounding structures. The perineal raphe is visible and pronounced to varying degrees. The perineum is an erogenous zone. This area is also known as the taint or gooch in American slang.
Hemorrhoids, also known as piles, are vascular structures in the anal canal. In their normal state, they are cushions that help with stool control. They become a disease when swollen or inflamed; the unqualified term hemorrhoid is often used to refer to the disease. The signs and symptoms of hemorrhoids depend on the type present. Internal hemorrhoids often result in painless, bright red rectal bleeding when defecating. External hemorrhoids often result in pain and swelling in the area of the anus. If bleeding occurs, it is usually darker. Symptoms frequently get better after a few days. A skin tag may remain after the healing of an external hemorrhoid.
In anatomy, a fistula is an abnormal connection joining two hollow spaces, such as blood vessels, intestines, or other hollow organs to each other, often resulting in an abnormal flow of fluid from one space to the other. An anal fistula connects the anal canal to the perianal skin. An anovaginal or rectovaginal fistula is a hole joining the anus or rectum to the vagina. A colovaginal fistula joins the space in the colon to that in the vagina. A urinary tract fistula is an abnormal opening in the urinary tract or an abnormal connection between the urinary tract and another organ. An abnormal communication between the bladder and the uterus is called a vesicouterine fistula, while if it is between the bladder and the vagina it is known as a vesicovaginal fistula, and if between the urethra and the vagina: a urethrovaginal fistula. When occurring between two parts of the intestine, it is known as an enteroenteral fistula, between the small intestine and the skin as an enterocutaneous fistula, and between the colon and the skin as a colocutaneous fistula.
An anal fissure is a break or tear in the skin of the anal canal. Anal fissures may be noticed by bright red anal bleeding on toilet paper and undergarments, or sometimes in the toilet. If acute they are painful after defecation, but with chronic fissures, pain intensity often reduces and becomes cyclical.
Colorectal surgery is a field in medicine dealing with disorders of the rectum, anus, and colon. The field is also known as proctology, but this term is now used infrequently within medicine and is most often employed to identify practices relating to the anus and rectum in particular. The word proctology is derived from the Greek words πρωκτός proktos, meaning "anus" or "hindparts", and -λογία -logia, meaning "science" or "study".
Ileostomy is a stoma constructed by bringing the end or loop of small intestine out onto the surface of the skin, or the surgical procedure which creates this opening. Intestinal waste passes out of the ileostomy and is collected in an external ostomy system which is placed next to the opening. Ileostomies are usually sited above the groin on the right hand side of the abdomen.
A fistulotomy is the surgical opening of a fistulous tract. They can be performed by excision of the tract and surrounding tissue, simple division of the tract, or gradual division and assisted drainage of the tract in a seton; a cord passed through the tract in a loop that is slowly tightened over a period of days or weeks.
The anal canal is the part that connects the rectum to the anus, located below the level of the pelvic diaphragm. It is located within the anal triangle of the perineum, between the right and left ischioanal fossa. As the final functional segment of the bowel, it functions to regulate release of excrement by two muscular sphincter complexes. The anus is the aperture at the terminal portion of the anal canal.
A seton or seton stitch is a procedure used to aid the healing of fistulae.
The anal glands or anal sacs are small glands near the anus in many mammals. They are situated in between the external anal sphincter muscle and internal anal sphincter muscle. Their function in humans is unclear.
Stapled hemorrhoidopexy is a surgical procedure that involves the cutting and removal of anal hemorrhoidal vascular cushion, whose function is to help to seal stools and create continence. Procedure also removes abnormally enlarged hemorrhoidal tissue, followed by the repositioning of the remaining hemorrhoidal tissue back to its normal anatomic position. Severe cases of hemorrhoidal prolapse will normally require surgery. Newer surgical procedures include stapled transanal rectal resection (STARR) and procedure for prolapse and hemorrhoids (PPH). Both STARR and PPH are contraindicated in persons with either enterocele or anismus.
Anorectal abscess is an abscess adjacent to the anus. Most cases of perianal abscesses are sporadic, though there are certain situations which elevate the risk for developing the disease, such as diabetes mellitus, Crohn's disease, chronic corticosteroid treatment and others. It arises as a complication of paraproctitis. Ischiorectal, inter- and intrasphincteric abscesses have been described.
Goodsall's rule relates the external opening of an anal fistula to its internal opening. It states that if the perianal skin opening is posterior to the transverse anal line, the fistulous tract will open into the anal canal in the midline posteriorly, sometimes taking a curvilinear course. A perianal skin opening anterior to the transverse anal line is usually associated with a radial fistulous tract.
Lateral internal sphincterotomy is an operation performed on the internal anal sphincter muscle for the treatment of chronic anal fissure. The internal anal sphincter is one of two muscles that comprise the anal sphincter which controls the passage of feces. The procedure helps by lowering the resting pressure of the internal anal sphincter, which improves blood supply to the fissure and allows faster healing. The procedure has been shown to be very effective, with 96% of fissures healing at a median of 3 weeks in one trial.
In humans, the anus is the external opening of the rectum located inside the intergluteal cleft. Two sphincters control the exit of feces from the body during an act of defecation, which is the primary function of the anus. These are the internal anal sphincter and the external anal sphincter, which are circular muscles that normally maintain constriction of the orifice and which relax as required by normal physiological functioning. The inner sphincter is involuntary and the outer is voluntary. Above the anus is the perineum, which is also located beneath the vulva or scrotum.
LIFT technique is the novel modified approach through the intersphincteric plane for the treatment of fistula-in-ano, known as LIFT procedure. LIFT procedure is based on secure closure of the internal opening and removal of infected cryptoglandular tissue through the intersphincteric approach. Essential steps of the procedure include, incision at the intersphincteric groove, identification of the intersphincteric tract, ligation of intersphincteric tract close to the internal opening and removal of intersphincteric tract, scraping out all granulation tissue in the rest of the fistulous tract, and suturing of the defect at the external sphincter muscle. The procedure was developed by Thai colorectal surgeon, Arun Rojanasakul, Colorectal Division Department of Surgery, Chulalongkorn University in Bangkok, Thailand. The first report of preliminary healing result from the procedure were 94% in 2007
Rectal discharge is intermittent or continuous expression of liquid from the anus. Normal rectal mucus is needed for proper excretion of waste. Otherwise, this is closely related to types of fecal incontinence but the term rectal discharge does not necessarily imply degrees of incontinence. Types of fecal incontinence that produce a liquid leakage could be thought of as a type of rectal discharge.
Anorectal disorders include conditions involving the anorectal junction as seen in the image. They are painful but common conditions like hemorrhoids, tears, fistulas, or abscesses that affect the anal region. Most people experience some form of anorectal disorder during their lifetime. Primary care physicians can treat most of these disorders, however, high-risk individuals include those with HIV, roughly half of whom need surgery to remedy the disorders. Likelihood of malignancy should also be considered in high risk individuals. This is why it is important to perform a full history and physical exam on each patient. Because these disorders affect the rectum, people are often embarrassed or afraid to confer with a medical professional.
Dyssynergia is any disturbance of muscular coordination, resulting in uncoordinated and abrupt movements. This is also an aspect of ataxia. It is typical for dyssynergic patients to split a movement into several smaller movements. Types of dyssynergia include Ramsay Hunt syndrome type 1, bladder sphincter dyssynergia, and anal sphincter dyssynergia.
Fistulectomy is a surgical procedure where a surgeon completely removes a fistula, an abnormal tract that connects two hollow spaces of the body. In comparison to other procedural options of treating fistulae such as fistulotomies, where a fistula is cut open but not completely removed, and seton placement, where a rubber band seton is passed through the tract and left post-operation as a means to allow drainage of the fistula, fistulectomies are considered to be a more radical approach. The total removal of a fistula may damage nearby structures in the process.