Fistulotomy for anal fistula

An ankle fistula 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 (Fig. 1.8.2.2.2-0-1). 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 Ankle fistula is suitable for: 1. Low-position straight or curved anal fistula, which can be used if there is not much fiber tissue in the wall. 2. Submucosal hernia or anal canal. 3. In patients with multiple anal fistula, in order to reduce the defect of the tissue around the anal canal, the collateral canal or the smaller fistula can be used for incision. 4. Cooperate with thread-hanging therapy to treat high or complex anal fistula. Contraindications In the case of acute infection or empyema, the infection must be controlled first. Preoperative preparation 1. Complexity or high anal fistula should be done with 40% iodized oil. The method is: first enema with warm saline, drain the stool, and take a bath once. Place a metal sign on the anal and outer mouth. Use a contrast needle (use an epidural needle or a small puncture needle to remove the head) and insert it from the outer mouth. The pipeline was washed with 3% hydrogen peroxide and saline to increase the success rate of the contrast. Then, the contrast agent was injected under the X-ray fluoroscopy to observe the trend of the contrast agent, and the positive and lateral positions were taken. 2. Shave the skin around the anus. 3. Give fluid to the body 1d before surgery. 4. If necessary, do soapy water enema 4 to 6 hours before surgery. Surgical procedure 1. Low-grade anal fistula for fistula incision (1) The stone removal position. After the probe is used to determine the direction and depth of the fistula, the slotted probe is inserted from the outer port, the inner port is opened, and the entire layer of the fistula is cut along the direction of the probe groove. (2) Use a curette to scrape the necrotic tissue and granulation tissue of the fistula wall, and if necessary, remove the surrounding scar tissue, and fill the wound with oil gauze. 2. Low-bend anal fistula for fistula incision (1) The stone removal position. First insert a piece of white gauze into the anal canal, and then inject the disinfected methylene blue or amethyst from the outer mouth of the fistula with a needle that smoothes the tip of the needle. If the gauze is dyed with color, it will help to find the inner mouth. Methylene blue is also injected to facilitate the identification of the fistula during surgery. (2) Slowly insert the slotted probe from the outer mouth of the fistula and stop if there is resistance. Then, the skin, the subcutaneous tissue, and the outer wall of the fistula were cut with an electric knife in the direction of the probe to partially open the fistula. (3) Insert the slotted probe into the remaining portion of the fistula and gradually cut the surface tissue of the probe with an electric knife in the same way until the entire fistula is completely cut. (4) Use a curette to scrape off the necrotic tissue and granulation tissue stained with methylene blue on the wall of the fistula. (5) Cut off the skin and subcutaneous tissue at the edge of the wound to make a wide wound. After careful hemostasis, the wound is filled with iodoform gauze strips or oil gauze. 3. Hoof-shaped anal fistula incision plus hanging line therapy The hoof-shaped anal fistula is a special type of anal fistula that penetrates the sphincter. It is also a high-positioned anal fistula. The fistula is surrounded by the anal canal and passes from one side of the rectal fossa to the opposite side, becoming a semi-circular shape like a shoe, hence the name. There is an inner mouth near the tooth line, and the number of outer mouths is large, scattered on the left and right sides of the anus, and there are many branch pipes that spread to the surroundings. The hoof-shaped anal fistula is divided into two types: the front shoe iron shape and the rear shoe iron shape. The latter is more common, because the posterior tissue of the anal canal is looser than the front, and the infection is prone to spread. A hoof-shaped anal fistula is a type of high-curved anal fistula. Incision plus hanging line therapy should be used. (1) The iron-shaped anal fistula of the hind-shoulder is first inserted from the outer mouth of the two sides with a slotted probe, and the fistula is gradually cut until the two sides of the tube meet near the mid-line, and then the inner mouth is carefully probed by the slotted probe. The inner mouth is mostly at the tooth line of the midline of the anal canal. (2) If the fistula is passed under the anorectal ring, the lower and shallow portions of the fistula and external sphincter can be completely cut at one time. (3) If the internal mouth is too high, the fistula is passed over the rectum ring of the anal canal. That is, the fistula of the lower part of the external sphincter skin, the shallow part and the lower part of the sphincter skin are first cut, and then the rubber band is used to pass through the remaining pipe mouth, and is led out through the inner mouth and tied to the anorectal ring, so as to avoid cutting the anal canal once. The rectal ring causes anal incontinence. (4) Finally, the skin and subcutaneous tissue at the edge of the wound are cut off, the wound surface is opened, and the granulation tissue of the fistula wall is scraped off. The wound is filled with iodoform gauze or oil gauze. complication Bleeding Not much. Often due to vascular retraction and not timely ligature. It can be temporarily filled with gauze and pressure-wrapped. If the bleeding still does not stop, surgery must be stopped. 2. Anal incontinence Although rare, it is a serious complication. Mostly because the anorectal ring is cut off, or partially cut off, and the anus is completely incontinent or partially incontinent. 3. Anal scar contracture deformation Mainly due to the large and deep anal fistula wounds, the resection of the anal margin tissue is too much, the wound edge collapses, and the scar shrinks after healing. Secondly, after cutting the anal ligament or removing the tailbone during surgery, the anus is displaced forward, changing the angle between the rectum and the anal canal. 4. Wound growth is slow If the anal fistula is large and deep, slow growth is normal. If the growth is too slow, consider the following factors: 1 patients have other diseases, such as diabetes, tuberculosis, etc.; 2 foreign bodies in the wound, such as silk, dressings, fish bones, etc.; 3 improper dressing, treatment is not timely, causing wound adhesion and False road formation, and even wound infection. 5. Rectal mucosal prolapse Often accompanied by anal incontinence, the two causes the same reason, if necessary, must be treated at the same time. 6. 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.