Updated: Mar 3
What is a fistula?
The anal fistula (fistula in ano) is an abnormal passage or a track (communication) between the anal canal or rectum and the surface of the skin. Consultant Gastroenterologist, Dr Shivanshu Misra states that rare forms can communicate with the vagina or other pelvic structures.
The historical meaning of fistula:
The disease-origin fistula is as old as mankind. Thousands of years ago, Hippocrates referred to surgical therapy for the fistulose disease. In 1376, the English surgeon John Erden (1307–1390) wrote "Texas of Fistula Into, Hemorrhoids and Clusters", using fistulotomy and the seton suture.
Literal and contextual evidence suggests that a central plot device in Shakespeare's play All Well's End is that the French king's fistula-in-ao. In Shakespeare's time, the anal fistula was known to the general public. In addition, Shakespeare would have known about the anal fistula of John Alderney, who was an ancestor of Shakespeare's mother. All-Way That Ends Well tells the story of Helen, the daughter of a physician who succeeds in healing the French king of his debilitating fistula.
No passage in the play gives any clue to the exact size or nature of the fistula. There is a suggestion that this may be the common fistula-in-ao, about which John of Adderney - father of proctology - wrote extensively; It may optionally be a chronic abscess with a discharge of the sinuses, including the finger or breast.
Historical references indicate that Louis XIV was treated for the anal canal in the 18th century. In the late 19th and 20th centuries, prominent physicians/surgeons like Goods and Miles, Milligan and Morgan, Thompson, and Lockhart-Mamari contributed significantly to the treatment of anal fistula. These physicians offered theories on pathogenesis and classification systems for fistula-in-AO.
Over the past 50 years, many surgeons have introduced new techniques (losing control of faeces) in an effort to reduce recurrence rates and incontinence complications. But despite 2500 years of experience, an anal fistula is a dangerous surgical disease.
Sequence of events
There is a connection between a perianal abscess and a fistula in the onion: a fistula almost always develops as a result of an abscess. When the abscess opens spontaneously (or has been opened surgically), a fistula may occur. An anal abscess is an infected cavity that is filled with pus found near the anus (opening of the anal canal) or rectum (part of the large intestine adjacent to the anal canal).
This rectum can be located inside the anus by a blockage of the anal glands. An abscess produces pain and swelling near the opening of the anus. Fever may also be present. If left untreated, the abscess can "bore" through the inside tissues - thus creating an unnatural "tunnel" which can or won't have a painful external opening. This tunnel may have many branches called fistula or fistula-in-anno.
The fistula can develop from untreated abscess inside the anal canal, and may also be a symptom of a digestive disease called Crohn's disease called inflammatory bowel disease. Other factors that can make or exacerbate the fistula are HIV infection, tuberculosis and radiation therapy for prostate or rectal cancer. The tube may be singular or in multiples.
The first symptoms of a fistula are a throbbing sensation, visible opening, swelling and tenderness. Often, pus leaks into the fistula from infected glands. In rare cases, stool may leak out of the fistula during discharge. In AO, the fistula usually presents as a small abscess - such as opening around the anus at a distance of a few mm. A pair of inches in both directions. This opening keeps the pus or blood out continuously.
Patients often have a history of previous pain, swelling, and spontaneous or planned surgical drainage of the amorphous abscess.
Perianal discharge, painful swelling in the perianal region, bleeding, exfoliation of the skin and a visible external opening in the perineal region.
A physician may be able to diagnose an anal fistula by performing a physical examination of the area around the anus. However, if external signs, such as an opening in the skin, are missing, then an internal examination will be necessary. A device called a proctoscope is used to inspect the anal canal.
These are not done for routine fistula evaluation. They can be helpful when the primary path is difficult to identify or in the case of recurrent or multiple fistulas to identify the secondary track or omission primary opening.
This involves an injection of contrast through the external opening, followed by X-ray images to stipulate the course of the fistula tract.
Findings looking at primary path course and secondary E are with 80–90% operative findings.Overview of Primary Path Course and Secondary Extension.
Surgery - Fistulotomy / Fistulectomy
An anal fistula usually lasts until it's surgically removed. The fistula pathway must be opened with the source of infection. Typically, the tissue surrounding the outer opening and the inner opening are enlarged with a small margin of tissue, known as a fistototomy. The flow of the complete tract is called fistullectomy. The laying-open technique (fistulotomy) is useful for 85–95% of the primary fistula. Complete fistullectomy creates larger lesions that take longer to heal and provides no recurrence benefit over fistulotomy.
Fistulotomies work well for fistulas that are relatively on the brink of the skin. However, for deep fistulas, surgeons may choose to use a seton. A seton is a piece of suture material that is passed through the opening of the outer skin, the internal opening in the anal canal, along the anal canal, exiting the anus. The suture material is then tied into a loop, which is gradually tightened over a period of weeks. This ultimately has the same effect as fistulotomy - allowing the fistula to open and fix it.