Anal fistula surgery

Anal fistula surgery is used for the surgical treatment of anal fistula. Anal fistula mainly invades the anal canal, rarely involves the rectum, and is an infectious duct that communicates with the perianal skin. The inner mouth is located near the tooth line, and the outer mouth is located on the perianal skin. It is a common disease in anal canal and rectal diseases. There are many classification methods for anal fistula, but it is not only related to the location of the abscess around the anorectal rectum, the relationship between the fistula and the anal sphincter. At present, the anal fistula is divided into four categories according to the relationship between the fistula and the sphincter. 1 sphincter anal fistula: mostly low anal fistula, the most common, accounting for about 70%, is the consequence of abscess around the anal canal. The fistula only passes through the internal sphincter, and there is usually only one outer mouth, which is closer to the anal margin, about 3 to 5 cm. A small number of fistulas are up, forming a blind end between the rectal ring muscle and the longitudinal muscles or penetrating into the rectum to form a high sphincter spasm. 2 sphincter anal fistula: can be low or high anal fistula, accounting for about 25%, is the consequence of the ischial rectal abscess. The fistula passes through the internal sphincter, between the superficial and deep parts of the external sphincter, and there are often several external ports, and the branches communicate with each other. The outer mouth is closer to the anal margin, about 5cm, and a few fistulas pass up through the levator ani muscle to the connective tissue adjacent to the rectum, forming a pelvic rectal fistula. 3 sphincter anal fistula: high anal fistula, rare, accounting for 5%. The fistula passes up the levator ani muscle and then penetrates the skin down to the ischial rectal fossa. Because the fistula often involves the anorectal ring, it is difficult to treat and requires staged surgery. 4 sphincter anal fistula: the least seen, accounting for 1%, for the consequences of pelvic rectal abscess combined with sciatic rectal abscess. The fistula communicates with the rectum through the levator ani muscle. This anal fistula is often caused by Crohn's disease, colon cancer or trauma, and treatment should pay attention to its primary lesion. The above classification is more detailed in the high and low positions, which is conducive to the choice of surgical methods. Clinically, the anal fistula is often divided into two categories: low or high. The former is below the anorectal ring and the latter is above the anorectal ring. There are also an anal fistula from the shape of the fistula, which is divided into straight, curved and hoof-shaped anus. Straight sputum is often a low anal fistula, and the hoof-shaped anal fistula is often high, and the flexion can be low or high. From the pathological changes, it can be divided into suppurative anal fistula and anal fistula caused by specific infection. Anal fistula can not heal itself and must be treated surgically. The principle of surgical treatment is to cut all the fistulas and, if necessary, remove the scar tissue around the fistula, and gradually heal the wound from the base. Treatment of diseases: anal fistula Indication Anal fistula surgery is applicable to: 1. Applicable to the lower anal fistula within 3 ~ 5cm from the anus, there are internal and external mouth, clinically can clearly touch the wall of the cord, no branch and acute infection. 2. As an auxiliary method for complex anal fistula incision or excision. Contraindications In the case of acute infection or empyema, the infection must be controlled first. Preoperative preparation 1. Shave the skin around the anus. 2. Give fluid to the body 1d before surgery. 3. If necessary, do soapy water enema 4 to 6 hours before surgery. Surgical procedure 1. First bind a rubber band at the end of the probe, then gently probe the probe head from the outer mouth of the fistula, find the inner mouth near the anal canal; then extend the index into the anal canal and explore Needle, bend the probe head and pull it out from the anus. Be careful not to use violence when inserting the probe to prevent false passages. 2. Pull the probe head completely out of the inner mouth of the fistula, and let the rubber band pass through the outer mouth of the fistula into the fistula. 3. Lift the rubber band, cut the skin layer between the inner and outer mouths of the fistula, tighten the rubber band, and clamp it with the hemostatic forceps next to the subcutaneous tissue; tighten the rubber band with a thick thread under the hemostat and do double ligation, Then release the hemostat. The incision is applied with Vaseline gauze. complication Pain The general pain can be tolerated by the patient. If there is severe pain, the patient is unbearable, mostly because the hanging thread is too tight or the skin is not completely cut. 2. Urinary retention In addition to its own genitourinary system disorders, reactive urinary retention is mainly caused by pain. Anal canal nerves are closely related to the bladder and neck nerves. Anal stimulation can often cause posterior urethra and bladder neck spasm, especially in cases where anal canal is placed. As long as the cause of pain is removed, sedatives can often be administered to urinate. If you still can't urinate, you can give 0.25mg of carbachol subcutaneously. Those who still can not urinate 12 hours after surgery should be catheterized.