anal sphincter repair

Anal sphincter repair for surgical treatment of anal incontinence. Anal incontinence is a phenomenon in which feces are out of control through the anus or the ability to control is weakened. There are many causes of anal incontinence, and the degree of incontinence is very different. Mild incontinence is only manifested as incontinence of fecal or liquid feces; severe incontinence is completely out of control. Some manifested as accidental incontinence, night incontinence, and severe incontinence. Anal incontinence can be either habitual or due to the development of congenital nervous system deficiency, more common in the lumbosacral spina bifida or meningocele. The feeling of defecation and the movement of muscles of these patients are affected. When the rectum is filled, there is no intention, so there is no reflexive defecation activity. The anal external sphincter system and the pelvic floor muscles are relaxed under the absence of motor nerves, so the feces can leak out at any time. Anal incontinence can also be seen in cases of rectal anal trauma, but it is most common in postoperative anorectal malformation, especially in high anal atresia, rectal hypoplasia, blind end located above the levator ani muscle, lack of anal internal sphincter, external sphincter development A number of changes have taken place. External and external sphincter injuries, postoperative complications and scar formation may affect the function of the external sphincter. In addition, the failure of the rectum to pass through the muscle complex during rectal prolapse is also one of the causes of postoperative incontinence. According to our statistics, 70.1% of anal incontinence is secondary to high postoperative anal surgery, anal incontinence is also seen in anal diseases, such as anal rectal prolapse leading to sphincter relaxation, tendon or anal canal tumor traction, anal scar stenosis, etc. . Because the cause of anal incontinence and the degree of incontinence are very different, sometimes caused by several reasons at the same time, the treatment is quite complicated. Surgery should be carefully designed for each different case. In recent years, the proportion of incontinence after high-level anus-free surgery has decreased significantly. According to the 11th Asian Pediatric Surgery Academic Conference in 1992, the incidence rate ranged from 13% to 33%. The main reason was that pediatric surgeons paid enough attention to the anatomy and physiology of anal control, and designed and adopted it. The correct surgical method. The anal sphincter system consists of the anal internal sphincter and the external sphincter. The internal sphincter is a ring-shaped muscle that is thickened at the end of the rectum. It is a smooth muscle and belongs to the autonomic nervous system. There is no or only a small number of ganglion cells in the internal sphincter, so it is often in a contracted state, keeping the tension of the anus closes and preventing feces. When the lower rectum is stimulated by inflation pressure, the internal sphincter undergoes a reflex relaxation, allowing the feces to pass. The external anal sphincter itself can be divided into deep, shallow and subcutaneous. In recent years, an in-depth study of the anal external sphincter has been carried out, and it has been found that the superficial fibers of the external sphincter are only distributed under the perianal skin. The deep fibers are thicker and extend to the ventral aspect of the coccyx and tibia. The above three muscle fibers are fused to each other on the anterior side and are not easily distinguished, and are collectively referred to as a striated muscle complex. The complex and the levator ani muscle play the most important role in the control of defecation. In recent years, some scholars have proposed through continuous histological section studies that the external anal sphincter and the puborectalis should be regarded as an inseparable unity, which together constitute three important rings for controlling defecation, called the triple loop system. ). The top loop consists of the puborectal muscle and the external fibers of the external sphincter. It surrounds the rectum and ends at the pubis. The innervation is the subcutaneous branch of the pudendal nerve. The function is to shift the posterior wall of the rectum to the front to form a rectal angle. (intermediate loop) consists of the middle sphincter fibers, which surrounds the anterior wall of the rectum and terminates in the tailbone. It is dominated by the perineal branch of the iliac crest. The effect is to suspend the anterior wall of the rectum to make it backward. When the bottom ring contracts, the anal canal is fixed. The (base loop) consists of the subcutaneous fibers of the external sphincter. It surrounds the anus in a concentric shape and ends in the subcutaneous part of the anus. It is dominated by the descending branch of the phrenic nerve. The function is to pull the anus posterior wall forward and downward. The three-ring system performs fine and powerful control of the anus, and its effects are as follows: 1 Directly compressing different positions of the lower end of the rectum, in addition to which each ring can perform its own activities separately. 2 Through the kinking mechanism, the three rings reversely lock the lower end of the rectum, causing the anal canal to tilt and the posterior wall of the anus to extend, which not only ensures that the striated muscle system closes the anus quickly and completely, and also enters the feces at the lower end of the rectum. It is isolated from the sensitive area of the lower end of the rectum and achieves the function of controlling defecation. Complete control of the anus requires at least two rings of activity. If the integrity of the intermediate ring and the base ring can be preserved, the bowel movement can be controlled even if the top ring is lacking. Many cases of mild anal incontinence can be gradually restored after defecation training, and some anal incontinence children can partially or completely return to normal bowel movement with age, and only some cases eventually require surgery. Treatment of diseases: anal trauma Indication Anal sphincter repair for anal external sphincter due to surgery or traumatic injury, laceration, continuous interruption of the anorectal ring, residual sphincter retraction, etc., resulting in anal closure or anal incontinence due to weak residual sphincter contractility . Contraindications When the anus is too large, or the anal closure caused by more scar tissue is not strict, simply repairing the external sphincter still cannot solve the incontinence problem. An anesthesia should be performed first, followed by sphincter repair to create conditions for recovery after sphincter repair. In addition, this method is disabled due to incontinence caused by nerve damage. Preoperative preparation The bowel should be cleaned before surgery, and the enteral sterilization drug should be taken 3 days before the operation. The enema should be preserved with antibiotics on the morning of the operation. Surgical procedure 1. After detailed examination, clear the location of the sphincter's broken end, make a radial incision along the scar tissue or make a "U" shaped incision, the concave of the latter facing the anus to reduce the postoperative incision contaminated by feces. 2. After cutting the skin, flip the flap to the anus, then separate the scar in the subcutaneous tissue to find the broken end of the muscle. If necessary, use an electric stimulator to help determine the position of the muscle stump. The scar tissue is removed, but for the suture to be firm, some scars should be retained at the sphincter stump to reduce the chance of tearing the muscle fibers after suturing. 3. Stitch the sphincter broken ends, which can be sutured with silk thread or steel wire. After the two ends are pulled together, the needles are sutured and the subcutaneous tissue and skin are sutured intermittently. complication The main complication of external sphincter repair is the rupture of the suture muscle. The reason for the splitting is that the suture is too tight and affects the muscle blood supply; the second is the early postoperative bowel movement, wound infection. In case of wound infection, drainage should be cut early. If the sutured sphincter is partially ruptured, the stump is stuck near it, so it usually does not affect the surgical effect after healing.