Complex anal fistula refers to an anal fistula with 2 or more internal or external openings, and 2 or more fistulas or branches or blind ducts. Complex anal fistula is the most difficult in the treatment of anal fistula, because of its various causes and forms.
1. Repeated infection of anal fistula or abscess
In the early stage of infection, the lesion is generally confined to a space around the anus, but as the infection worsens, the pressure in the abscess cavity increases, and the infection spreads to other spaces. If it spreads to the opposite channel, it will form a horseshoe-shaped anal fistula, which usually appears in the anus. The posterior part either spreads through the perineal body in the anterior part, or spreads to the space between the internal and external sphincter, forming high fistula and suprasphincteric fistula. The more frequent the spreading attacks, the higher the position of the fistula, the more branches and the more complicated the treatment.
2. Improper surgical operation leads to complicating anal fistula
In the surgical treatment of anal fistula, inadequate exploration, artificial internal opening or residual branch can complicate a simple anal fistula. In particular, the residual branch can cause the wound to not heal for a long time or relapse after healing, which complicates the problem and requires After multiple operations, scar formation will also increase the difficulty of reoperation.
3. Other factors related to diseases
Complex anal fistulas can be caused by systemic diseases, such as Crohn’s disease involving the anus, which leads to Crohn’s anus, and multiple fistulas perianal; complex anal fistulas can also be caused by local factors, such as secondary infection of presacral cysts and hidradenitis suppurativa. "Anal fistula" caused by open drainage, although repeated incision and threading, the wound still cannot heal. There are also patients with other systemic diseases that affect wound healing, such as diabetes, tumor chemotherapy, blood diseases, etc., making simple anal fistulas unable to heal for a long time, which is also one of the reasons for complex anal fistulas.
Intermittent or continuous discharge of pus from the anus.
2. Swelling and pain
-Normally no pain, only feel the anal mouth swelling or falling pain, when the pus drains smoothly, the swelling and pain will be relieved immediately. Sometimes pain can be caused by the large internal mouth and the feces flowing into the pipe, especially when the pain is aggravated during defecation.
The continuous outflow of pus or secretions stimulates the perianal skin and causes dampness and itching, sometimes accompanied by perianal eczema.
4. Systemic symptoms
If the outer mouth is temporarily closed and pus accumulates, local swelling and pain may occur, and it may be accompanied by systemic symptoms such as fever and chills; after the outer mouth is ruptured, the symptoms can be quickly reduced or disappeared. Sometimes pain can be caused by the large internal mouth and the feces flowing into the pipe, especially when the pain is aggravated during defecation.
Visible rupture of the outer mouth, induration can be palpable if the outer mouth is closed. Sometimes when pressing the fistula, secretions may overflow from the outer mouth.
You can understand the depth of the fistula tube, the direction and the position of the internal opening by touching it. High anal fistulas are generally difficult to touch with rigid cords. Induration or depression can be felt in the inner mouth near the tooth line.
The main observation is whether the anal crypts have hyperemia, depression, and discharge. During the treatment, the probe can be used to check the position of the inner mouth.
4. Dyeing inspection
Place a piece of dry gauze in the anus and inject the methylene blue solution from the outer mouth. If the inner mouth is not closed, the gauze will be colored, which can help find the position of the inner mouth.
5. Magnetic resonance imaging (MRI)
MRI can accurately show the anatomical relationship between the anal fistula and the internal and external sphincter and levator ani and the relationship with the tissues around the anus, and clarify the position, scope and extent of the anal fistula invading the internal and external sphincter and levator ani, and provide guidance for anal fistula surgery.
According to the history and clinical manifestations of perirectal abscess spontaneous rupture or incision and drainage, combined with MRI examination can confirm the diagnosis.
Complex anal fistulas cannot be healed spontaneously. Surgical treatment is the most effective way to treat complex anal fistulas. However, when symptoms such as pus, redness, and pain occur during the onset, medications can be used to temporarily relieve the symptoms.
(1) External treatment Use huoxue swelling and pain relief lotion to sit in the bath, and apply golden ointment.
(2) Use of antibiotics Antibiotics can be used during the acute attack period, but generally do not exceed one week.
(3) Oral use of traditional Chinese medicine: Use 萆薢 Shenshi Decoction plus Huadu Shishitang plus or minus, and those with fever can use Xianfang to drink for life.
2. Surgical treatment
The causes and forms of complex anal fistula are diverse, so there are many types of surgical methods. How to rationally use one or several methods to treat the same patient has become the key to surgery. Principles of surgical treatment: ① adequate exploration; ② adequate drainage; ③ preserve the function and appearance of the anus as much as possible. Common surgical methods currently include:
(1) Incision Low complex anal fistula is the most common complex anal fistula in clinical practice. The treatment is relatively simple, with few sequelae and high cure rate. The surgical method is to use a probe to find out the direction of the fistula and the position of the internal opening, open the fistula all at once, remove the fistula wall and necrotic tissue, trim the wound edge, and drain the flow smoothly. This surgical method will not damage the anal straight ring, and there is generally no abnormal stool control function after surgery.
(2) Resection is mostly suitable for low complex anal fistulas that have been fibrotic. Use scissors to completely free the outer wall from the bottom of the fistula, remove the fistula and the internal and external openings together, and also remove the scar tissue around the fistula until the healthy tissue is exposed. The purpose of excision is to get rid of rotten flesh and facilitate the growth of new flesh. It is often used in combination with incision.
(3) The low-cut high-hanging method is suitable for high complex anal fistulas. Although this operation will damage part of the sphincter and have a certain anal deformity rate, the cure rate is relatively high. Most complex anal fistulas can be completely cured, and it is currently used clinically. The classic method. Its characteristic is that the part below the anorectal ring is directly incised, while the part above the anorectal ring is threaded. The low-cut high-hanging method avoids the pain of simply hanging the thread after cutting all the tissues, and has the advantages of shortening the treatment course, reducing scars and injuries, maintaining good functions, etc., and has a definite clinical effect.
(4) Two-way equal pressure drainage is suitable for high complex anal fistulas and horseshoe-shaped anal fistulas. In this operation, a half-cut thread hanging is used, and the inner mouth is first cut, extending 0.5 to 1 cm upward, and extending downward to outside the anal margin. Use a hemostatic forceps to probe from the incision to the upper end of the high fistula to the top, hang a thread on the top of the intestinal wall stoma, gather the two ends, and fix it with appropriate force. A latex tube with a side hole is placed in the fistula lumen and fixed to facilitate postoperative drainage and irrigation. The latex tube was removed about 7 days after the operation. About 10 days after the operation, the hanging silk thread was loose and was removed. This method effectively protects the "anal straight ring", the core structure of the anal canal, from being completely cut off during the operation, and effectively protects the anal function while ensuring the curative effect.
(5) Other surgical therapies In recent years, with the continuous deepening of minimally invasive surgery concepts and the innovation of biotechnology, high-tech medical biomaterials such as biopatch repairing the internal opening and bioprotein glue sealing fistulas have gradually been used in the treatment of complex anal fistulas Some surgical complications have been controlled to a certain extent, but there are also new problems that continue to arise. For the treatment of complex anal fistula, clinicians have been groping forward.
1. The purpose of the operation is to relieve symptoms and improve the quality of life. The operation itself will more or less cause sphincter damage, scar formation, and even abnormalities of exhaust, defecation and anal fine functions. Preoperative evaluation of the surgical plan is particularly important for the prognosis.
2. Anal fistula is a benign disease and will not endanger the patient's life. However, if the patient has more basic diseases and cannot tolerate surgery, you should not blindly pursue radical surgery and ignore its possible serious consequences
3. Complex anal fistula has a certain recurrence rate. Patients with diabetes, leukemia, Crohn’s disease, ulcerative colitis and other diseases should also actively treat the primary disease to reduce recurrence.
1. Clinicians should improve their surgical operation skills, avoid leaving branches and sinuses during the operation, and thoroughly remove the lesions as much as possible at one time to improve the cure rate.
2. Develop good living habits, defecate regularly, take a bath after defecation every day, and keep the anus clean, which has a positive effect on preventing infection.
3. Actively treat perianal abscess and simple anal fistula, so as not to delay the condition and develop into a complex anal fistula, increase the difficulty of the operation, prolong the healing time and seriously affect the anal function.
Department of Anorectal, Tongchuan District Hospital of Traditional Chinese Medicine, Dazhou City