Skin grafting after anal fistula excision

Skin transplantation after anal fistula resection is used for 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 Skin transplantation after anal fistula resection is suitable for the lower anal fistula. The inner mouth is located in the anal sinus, the outer mouth is distributed throughout the anus, the skin is pigmented, and the fistula is sneaked under the perianal skin, the hips or the large area. Contraindications 1. It is not advisable to have skin grafting for acute infection of the perianal. 2. High anal fistula. Preoperative preparation 1. The donor site must be free of infection or rash. Wash and shave before surgery; do not scratch the skin. Each time, the cells were sterilized once with 1:1000 thiomersal and 75% ethanol. 2. Oral antibacterial drugs 1d, such as sulfaguanidine, neomycin, succinyl sulfonamide and the like. 3. Shave the skin around the anus. 4. Give fluid to the body 1d before surgery. 5. If necessary, do soapy water enema 4 to 6 hours before surgery. Surgical procedure 1. According to the principle of low-complexity anal fistula resection, open all the mouth and all the pipes, and remove the scar skin from the necrotic space that spreads to the perianal and buttocks. 2. Scrape the necrotic tissue, remove the residual wall, cut the bottom of the wound, trim the wound edge into a beveled wound, and press the wound with a hot saline gauze towel. 3. Use the 2-0 gut to suture the internal and anal canal, leaving no dead space, and the anal canal is open. 4. According to the size of the wound, remove the medium-thickness skin on the inner side of the upper third of the thigh, and wrap the wound in the donor area as usual. 5. The skin piece is trimmed to the size of the wound and covered on the wound surface, and fixed with a fine non-absorbable line. 6. Make several small incisions on the skin to facilitate drainage of the subcutaneous exudate and reduce tension. 7. Fix a few needles on the bottom of the skin and the wound to prevent the flap from floating and shifting. The subcutaneous exudate was squeezed out with dry gauze. 8. Cover the Vaseline gauze, plus a gauze pad of the size of the skin, and pressurize the bandage with the retained long suture. Apply the gauze under pressure before and after. complication 1. Skin infection or necrosis: The method of prevention is that the skin should not be too thin, the wound should be completely hemostasis, and the skin should be fixed to prevent accumulation of gas and fluid under the skin. 2. Wound infection is the main complication. The prevention method is strict surgical indications. Preoperative preparation should be sufficient. All internal and iliac crest tissues should be removed during operation. The layers should be aligned when suturing, leaving no dead space. If the wound is infected, it should be opened immediately.