Posted 09 December 2007 - 01:03 AM
Anal FistulasAn anal fistula is an abnormal connection between the anal canal and the skin outside the anus. They are very common and are almost always the result of an abscess described above. They usually become obvious within a few months of having an abscess, but sometimes only show up a year or so later. They often manifest with more subtle findings, such as mild discomfort, persistent drainage, foul odor or simply a firm lump around the anus. For some patients the diagnosis of a fistula only becomes apparent after they develop another abscess in the same location as the first one. The treatment of fistulas is much more complicated than for an abscess. They do not resolve on their own and will generally cause problems for many years unless dealt with surgically. Surgery involves usually putting a patient to sleep and exploring the fistula tract. We usually try to identify the internal opening inside the anus. When we have done that, the fistula tract needs to be opened up along its entire length, cleaned out and allowed to heal.The problem with opening the fistula tract is that it often goes through part of the sphincter muscle and opening the tract may involve cutting some of this muscle around the anus. A person can have some of the muscle of the anal sphincters cut without much trouble, but if too much of the muscle is cut, then there is a risk a patient may develop trouble with control around the anus. This usually means difficulty controlling gas, but sometimes if too much of the sphincter has been cut, it can mean trouble with controlling stool. The term to describe this problem is fecal incontinence.Rest assured that it is the highest priority of every surgeon who operates on fistulas to make sure that nothing is done which will irrevocably injure the anal sphincter and cause someone to have control problems. For this reason, every fistula requires individual assessment at the time of surgery. If the tract of the fistula is felt to be quite shallow and not involve much muscle, then it can almost always be opened up without risk and allowed to heal. If, however, there is any concern about whether there is perhaps too much muscle involved, then surgeons have a number of tricks they can employ to cure a fistula.One of the most common of these is placement of a reactive seton suture. A reactive seton is simply a silk suture which goes around the entire fistula tract and which stays in the patient for usually 2 or 3 months. During this time, the suture partly cuts through some of the muscle, similar to the way a wire might cut through an ice cube, allowing the muscle to reconstitute as it cuts through. In some instances the suture works its way through the entire tract and simply falls out after a few months and the fistula is healed. In most cases, however, we need to carry out a second minor procedure in 2-3 months in order to cut out the seton and complete the opening of the fistula tract. Because our primary concern is not causing any undue injury to the sphincter muscle, we are very cautious when doing fistula surgery and will always err on the side of safety. This means that some people will need to undergo a 2 or more small operations over 3-6 months in order to get the fistula to heal safely. While this seem like a big production for a small problem, it is necessary in order ensure that people do not experience significant problems post op. Finally, each fistula is different. Some patients have them dealt with in one operation, some require several procedures. The key is to treat each fistula individually and make decisions based on how much muscle is involved. When dealing with fistulas, patience is the highest virtue and worth practicing.