Other conditions which affect the ano-rectum and may be confused with or occur concomitant with hemorrhoids include anal fistula and anal fissures.
A fistula is an abnormal communication between the inside of a hollow organ and the skin. In the case of an anal fistula the communication is from inside the rectum to the skin outside the anus or on the buttock. The inciting cause is trauma of defecation which causes a break in the mucosa of the rectum. Bacteria track into the tissue under the mucosa and form an abscess. The abscess eventually finds its way to the skin where it ruptures and drains. The outer opening may heal but the inner opening remains and permits the cycle to repeat itself. Patients often present with years of repeated abscesses in this area which drain, heal and return again.
Surgical treatment involves opening the entire fistula from its outer opening to its inner opening and allowing the wound to heal from the inside out thus obliterating the fistula. If the fistula track runs deep to the anal sphincter muscle, the muscle will need to be divided; however, doing so carries a risk of causing fecal incontinence. Often, when this is the case, the procedure will be done in two stages. During the first stage, the fistula is opened to the level of the anal sphincter muscle including the overlying skin or mucosa, but the sphincter is left intact. A strip of cotton tape called a “Seton” is passed around the sphincter muscle in this area and tied tight. This causes the sphincter muscle in this area to scar down. A few weeks later, it is safe to cut the muscle as it will not retract and open up but instead just stays in place and the remainder of the fistula can heal. The risk of incontinence is greatly reduced performing the procedure in this way when the sphincter is involved.
Two newer methods for treating anal fistula have recently been introduced. The first step with both methods is to scrape the inside of the fistula to expose fresh tissue that is more prone to healing.
The first method involves simply injecting the fistula with fibrin glue. Fibrin is a protein found in the blood which is involved in the final stages of causing blood to clot. The glue created from fibrin is effective at sealing the fistula. The recurrence rate is high, but it is a reasonable first attempt and has no risk of causing incontinence.
The second option is to use a collagen fistula plug. Collagen is the major structural protein which holds us all together. It is present throughout are bodies and forms the matrix upon which cells grow. Pure collagen has been used to create matrices for a variety of purposes. In this case a small plug of collagen in placed in the fistula tract and sutured into place. The tissues may then grow into the collagen and heal the fistula. This procedure may or may not be augmented with the use of fibrin glue as described above. This procedure still has a significant recurrence rate, but again is a very good option to try as it has no risk of causing incontinence.
A fissure is simply a crack or tear in the anal skin in the anal canal. The cause is also straining with bowel movement. They are often exquisitely painful. So much so, that when I see a patient in excruciating pain in the anus, the patient will not allow me to do a digital exam and I cannot see a thrombosed hemorrhoid, I will usually just treat for a fissure as the presumptive diagnosis. Surgical treatment involves doing a lateral sphincterotomy. The skin in the outer part of the anus is opened slightly to expose the sphincter muscle and the muscle is divided superficially. This does not carry the same risk of incontinence as when dividing the muscle for a fistula, because the location and degree of muscle division can be completely controlled by the surgeon. With a fistula, the area of muscle involvement is dictated by the disease.
Surgery for fissures can often be avoided with the use of topical Nitroglycerine applied directly to the anus. Nitroglycerine relaxes the muscles of the anal sphincter the same way it relaxes the smooth muscle of blood vessels when treating Coronary Artery Disease. It may cause a low blood pressure in normal patients even when applied to the anus in this manner and therefore, may not be suitable for everyone. It is; however, a good first line treatment option that often resolves the problem and avoids the need for surgery.
Surgical Hemorrhoidectomy may be combined with a Fistulotomy for concomitant anal fistula or with a sphincterotomy for concomitant anal fissure.