Overview of Anal Fistulotomy
An anal fistula, which is also called an anorectal fistula, is a common problem that affects the lower digestive tract in the United States. It is basically an infected tunnel that forms between the skin near the anus and the inside of the anus itself. This issue often starts with an infection in one of the anal glands, which can lead to an abscess (a pocket of pus). The infection can either drain out on its own or may require a surgeon to cut it open to let the pus out. After this happens, there’s usually a long-term tunnel, known as a fistula, left behind. This can result in repeated infections or constant drainage.
Apart from infections in the anal glands, some conditions like hidradenitis suppurativa (a skin condition causing small and painful lumps), trauma, cancer, tuberculosis, and Crohn’s disease (a type of inflammatory bowel disease) can also cause fistulas. However, the fistulas caused by these conditions are often different from the typical ones. The initial treatment for all anal pain and infections thought to be perineal (relating to the area between the anus and genitals) is often anesthetic examination and drainage of the pus.
A fistula can take a shallow or deep path relative to the external anal muscle that controls bowel movements. For shallow fistulas, a surgical procedure called a fistulotomy can be done. In this procedure, the whole length of the fistula is cut open and it heals into a flat scar. For deeper fistulas, a rubber band or strong thread, known as a Seton, is threaded through the fistula to prevent it from healing over before the infection has cleared. This approach helps slowly cut through the fistula while giving the deeper parts time to heal, reducing the risk of bowel incontinence.
Complex fistulas such as malignant (cancerous) fistulas require team-based care. This typically involves treatments like chemotherapy or radiation therapy. A Seton might also be used to ensure proper drainage and avoid interrupting treatment plans. Fistulas caused by Crohn’s disease are also challenging to treat. A Seton is commonly the first step in treatment, to prevent abscess or severe infection. Steroids and drugs, like Infliximab, can be used to control the disease and help heal the fistula.
Fistulas caused by hidradenitis suppurativa or tuberculosis are often treated with antibiotics, and Setons may be used to prevent abscesses from forming during treatment. Severe cases of perineal fistula diseases may require a colostomy, a procedure to divert fecal waste to an opening in the abdominal wall, to permit healing and to manage continued infections.
Anatomy and Physiology of Anal Fistulotomy
The area around your bottom is made up of two primary muscles, known as the internal and external anal sphincters. The external one, which encircles the anus, can be controlled voluntarily. The internal one, closer to the inside of the anal canal, operates involuntarily, meaning you can’t control it consciously. There are essentially four main types of a medical condition known as “fistula in ano”.
The most frequent type is called “intersphincteric”, located between the two muscles, with an opening close to the anus. Another type is “Trans-sphincteric,” which cuts across the external sphincter and has an opening more to the side and is associated with a certain type of abscess. The “Suprasphincteric” fistula goes above a muscle called the puborectalis moving sideways near the levator ani.
Last is the “Extrasphincteric” fistula, the least common type, which goes through the ischiorectal fossa and levator ani muscles, then into the rectal wall above the dentate line.
The majority of anorectal fistula are due to cryptoglandular abscesses, which means that the fistula’s internal opening is typically found at the dentate line. The diagnosis for the type of fistula is usually made during a specialized examination under anesthesia.
The manner in which the fistula is connected to the internal and external sphincter is crucial. Only a small portion of the external sphincter muscle can be cut without affecting bowel control. To avoid cutting too much of this muscle and to reduce the risk of losing bowel control, a surgical thread named a “Seton” can be inserted through the fistula. The Seton slowly cuts through the sphincter over time or can be left in place to allow healing around it.
The location of the fistula’s external opening can give clues about its origin, based on what’s called Goodsall’s rule. This rule describes where the fistula’s internal opening will be depending on the position of the external one. However, this rule has its limitations and is mainly used to provide a starting point in understanding simple fistulas.
Why do People Need Anal Fistulotomy
If you have a repeat problem with a perianal abscess (an abscess near your anus), that either drains on its own or is drained by a doctor, you might have what is called a chronic draining sinus tract. This is an area that continues to leak fluid for weeks or months. Sometimes, it can cause more pain and more fluid to drain. Doctors typically diagnose this condition based on your medical history and a physical exam.
If you have this condition, you might be suggested to have a procedure under anesthesia. This could be a fistulotomy, which is a surgery to open up the tunnel that has formed under your skin, or a Seton Placement, which involves putting a special type of thread or drain through the fistula to help it heal.
Before you have this procedure, it’s important for your doctor to know if you or any family members have Crohn’s disease or if you have any issues controlling bowel movements. These factors can affect the type of treatment that’s best for you. For instance, if you have Crohn’s disease or if the fistula is towards the front of the body in women (we call this an anterior fistula), the best option might be a non-cutting Seton placement instead of a fistulotomy. Also, if the doctor isn’t sure about how deep the sinus tract goes, a Seton can be a safer choice.
When a Person Should Avoid Anal Fistulotomy
There are a few situations where placing a Seton – a thread or cord that helps drain an abscess or fistula (a tunnel between internal organs and skin) – might not be the best choice. For instance, if there is an active infection or abscess, these need to be treated and drained first before the Seton can be placed. And if the internal opening of the fistula is found to be cancerous, then you would need cancer treatments instead.
Whether the fistula is new or long-term, a Seton can still be used unless there are other medical concerns. If the fistula is superficial, meaning it’s close to the skin’s surface on the back end of the body, and only involves a small part of a certain muscle (the sphincter muscle), then a simple surgical procedure (fistulotomy) can treat it.
However, for fistulas near the front of the body, particularly in women, or in people who have had issues with bowel control or have Crohn’s disease, a fistulotomy is not the best choice as it can lead to a greater chance of losing control over bowel movements. In these cases, it’s recommended that, after a Seton is placed, these patients should continue to see colorectal specialists for more specialized surgery options.
Equipment used for Anal Fistulotomy
The procedure is carried out in an operating room, with the patient either sleeping under general anesthesia or relaxed with strong sedatives. The patient is positioned lying on their stomach or with their legs elevated and bent, depending on whether the condition is located at the front or back of the anus. The doctors will need special tools to spread the anus for better visibility.
For the procedure, commonly known as Seton, a variety of items such as a loop of blood vessel, a strong nylon thread, or a rubber band may be used. To find the specific area of the condition, the doctor may use something similar to a special probe used in tear duct examinations. They might also use a small syringe filled with a bubbly solution called hydrogen peroxide, connected to a small tube known as an angiocatheter, which they will inject into the affected area.
Sometimes, the doctor might use a local painkiller injection at the end of the procedure to manage any discomfort after the surgery. Finally, a special dressing will be applied to the area to help manage any fluid that may come out after the surgery.
Who is needed to perform Anal Fistulotomy?
The procedure is typically done by a surgeon and a helper. This helper’s role is to hold a medical tool, known as an anal retractor, which makes opening and looking into the inner part of the body easier. This also allows them to handle the ‘Seton,’ a type of string used for stitching the two sides together.
Preparing for Anal Fistulotomy
The Seton procedure, a surgical method used to treat certain anal conditions, doesn’t require much preparation from the patient’s side. Some people may take an enema in the morning before the procedure. An enema is a liquid treatment introduced into the rectum to stimulate a bowel movement and clean out the lower part of the bowel. This helps to ensure the rectal area is free from stool.
The other preparation steps mainly involve making sure the patient is positioned right in the operating room and all the necessary surgical instruments, including the chosen Seton material, are available. The Seton material is a thread-like device that is used during the procedure.
As a precaution, doctors may also give antibiotics before the operation. These are used to protect against infection from certain types of bacteria often found in the gut. Remember, the main goal here is to ensure your safety, and these preparations help in doing so.
How is Anal Fistulotomy performed
The procedure you’re undergoing take place in an operating room. You’ll be given medication to make you sleepy, and some surgeons may opt to put you under general anesthesia, which means you’ll be asleep for the whole thing. The position you’ll be placed in for the surgery depends on exactly where the issue is located- either lying on your stomach or with your legs raised and spread apart. If the issue is towards the front of your anus, it’s more likely you’ll lie on your stomach, whereas if it’s towards the back, you’ll be positioned with your legs raised. This helps make everything easier to see and reach.
Once you’re in position, the surgeon will use a special tool – kind of like the ones eye doctors use to unblock tear ducts – to look at and explore the problem area. In most cases with chronic conditions, this tool can find the internal problem easily. If identification is hard, they might gently inject a solution into the external area which will allow them to see it from the inside. This method lets the surgeon see the exact location of the issue.
Then, a thick surgical string or a rubber band is attached to the tool and threaded through the issue. This surgical string, or ‘seton’, is then stitched in a few places to make sure it stays in place. If it’s a cutting seton, the surgeon will tighten it a little more each week. If it’s a non-cutting seton, it’s usually left loose. Either way, this is done to help drain the area and improve healing.
If the issue can’t be found, the surgeon will be very careful not to force anything, as they don’t want to create new problems. Instead, they’ll open up as much of the external area as possible and make plans to look again under anesthesia in a few weeks. In the meantime, they might arrange for a CT scan or an MRI with special contrast to help them see what’s going on.
After the procedure, the surgeon will use a local anesthetic to help with any pain you may feel right afterward and apply dressings to the area. Then, they’ll make detailed notes about your procedure, including where the issue was, what they did, and any future plans for the surgical string or seton.
Possible Complications of Anal Fistulotomy
This medical procedure can come with a few issues. One potential issue specific to this procedure is not being able to find and drain an abscess (or pus-filled area) or find the pathway of a fistula (an abnormal connection between two parts of the body). Another risk is accidentally creating a false fistula tract.
There might be some leakage of stool with the insertion of the Seton, a special medical thread. Binding and cleaning guidance should be provided if this happens. There may be some minor bleeding after the procedure, which is usually trivial, but it’s important to monitor you. Infections aren’t typical, but they can happen.
If an infection does occur, it may need immediate attention. Mild cases might only require oral antibiotics and inspection under anesthesia. However, severe cases, such as a perineal necrotizing infection, which involves a devastating infection of the skin and tissues, may require intravenous (or IV) antibiotics and further examinations.
Incontinence, or the inability to control bowel movements, is rare with the Seton placement. If the internal opening isn’t identified during the procedure, the fistula might come back in a more complicated form.
What Else Should I Know About Anal Fistulotomy?
An anal fistula, which is an abnormal tunnel connecting your anus to your skin, often happens after having an anal abscess that either drained on its own or required surgical draining. If an anal fistula develops without an associated abscess, this could signal other conditions such as Crohn’s disease, hidradenitis (a long-term skin condition causing abscesses and scarring), or even cancer in the perineum (area between the anus and genitals). These cases should be thoroughly checked out.
Women who have fistulas near the front of the anal area, which can happen after giving birth, should expect a treatment called a Seton placement. This involves placing a piece of thread or surgical string through the fistula to help it heal.
General surgeons can often treat straightforward fistulas. However, if the fistula is complex, it’s best to see a specialist like a colorectal surgeon, who can provide the best care.