WHAT IS AN ANAL ABSCESS?
An anal abscess is an infected pocket filled with pus close to the anus or rectum. 90% of abscesses are caused by an infection of the internal gland in the anal canal. Bacteria or fecal matter can clog an anal gland and tunnel into the tissue around the anus or rectum. When the gland gets clogged, the infection may collect into a cavity called an abscess.
WHAT IS A FISTULA?
A fistula is a tunneled tract from one part of the body to another. An anal fistula is frequently the result of a previous or current anal abscess. This can occur in up to 50% of patients with abscesses. A fistula is a tunnel that connects a clogged internal anal gland to the outside skin.
WHAT ARE THE SYMPTOMS?
Usually, patients experience pain, swelling, redness, fever, and drainage around the anus. Inflammation can cause spasm of the pelvic floor which can result in difficulty with urination or difficulty with defecation. Hot water sitz baths can alleviate these symptoms, but some patients may need a foley catheter if they are unable to urinate. Rectal bleeding and irritation of the perianal skin may also occur especially in patients with a fistula.
HOW ARE THEY CLASSIFIED?
Abscesses and fistulae are classified by their location related to the sphincter muscles. Types of abscesses include perianal, ischioanal, intersphincteric, and supralevator. If the abscess spreads partially around the anus or the rectum, it is termed a horseshoe abscess.
Types of fistulas include submucosal, 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.
HOW ARE ABSCESSES TREATED?
An abscess is treated by making an incision along the skin near the anus to surgically drain the infected cavity. This can usually be done in a doctor’s office with local anesthetic. Some patients require deeper anesthesia in an operating room. Hospitalization and antibiotics are rarely required for patients with severe infections or decreased immunity.
Antibiotics alone are not an adequate alternative to drainage of the infection since antibiotics are unable to penetrate the abscess cavity.
HOW ARE FISTULAE TREATED?
Surgery is required to cure an anal fistula as there are no medical treatments available for this problem. If the fistula is simple (involves less than 30% of the sphincter complex), a fistulotomy may be performed. A fistulotomy involves unroofing the tract by dividing the intervening skin down to the fistula itself. This connects the internal and external openings creating a groove so that the fistula heals from the inside out. It must heal from the deeper layers to the superficial layer. Fistulotomy has a 95% success rate with a low risk of recurrence. This high success rate is balanced with risk of bowel incontinence (inability to control stool) which may occur from damage of the anal sphincter muscle. Small amount of muscle can usually be safely divided to treat the anal fistula without compromising continence. Your surgeon will assess whether a fistulotomy is appropriate for a given patient. Most fistulae are simple and can be treated in this manner.
In addition to fistulotomy, there are a number of other surgical treatment options for anal fistula which do not involve division of the sphincter muscles. The two most common procedures utilized in these patients are the endoanal advancement flap (ERAF) and the ligation of intersphincteric fistula tract (LIFT procedure). These procedures have a much lower success rate with around 50% chance of recurrence. Certain conditions, such as Crohn’s disease, malignancy, radiated tissue and previous attempts at repair, and smoking, increase the likelihood of failure. Although the sphincter muscle is not divided in this procedure, mild to moderate incontinence has still been reported.
WHAT IS A SETON?
If a significant amount of sphincter muscle is involved in the fistula tract, a fistulotomy is not recommended as the initial procedure. Your surgeon may place a draining seton which is a thin piece of rubber or suture material. This is encircled around the entire fistula tract and secured to itself. The seton may be left in place for several weeks (or indefinitely in some cases). The purpose is to control drainage, reduce the inflammation, and allow the fistula to “mature” (form a solid tract of scar). You can still have normal bowel function with a seton in place. Once all the inflammation resolves and a mature tract has formed, you and your surgeon may consider all the various surgical options as discussed above.
WHAT IS THE RECOVERY LIKE FROM SURGERY?
Pain after surgery is controlled with pain medication, sitz baths, fiber, and laxatives to help with bowel movements. Patients should plan for time at home using sitz baths and use laxatives to avoid the constipating effects associated with prescription pain medication. Discuss with your surgeon the specific care and time away from work prior to your surgery.
ABOUT COLON AND RECTAL SPECIALISTS
Colon and Rectal Specialists was founded in 1913. We are a group of dedicated fellowship trained colorectal surgeons. We are experts in the surgical and non-surgical treatment of diseases of the colon, rectum, and anus. Our surgeons have all completed advanced surgical training in the treatment of these diseases in addition to full general surgical training. We are well-versed in the treatment of both benign and malignant diseases of the colon, rectum, and anus and are able to perform routine screening examinations and surgically treat conditions when indicated.
ABOUT C.A.R.E.S. CENTER
Colon and Rectal Endoscopy and Surgery (CARES) Center is our state-of-the-art Ambulatory Surgery Center. Our center has been accredited by the Accreditation Association for Ambulatory Health Care (AAAHC) and has been given Medicare Deemed Status by CMS. We perform a variety of services including: screening colonoscopies, hemorrhoidectomy, abscess and fistula surgery, fissure surgery, pilonidal surgery, and surgery to treat fecal incontinence. Learn more about us at www.crspecialists.com.
