Anal atresia is a malformation of the human rectum. In this case, the opening of the anus is missing or is not created correctly.
What is anal atresia?
Anal atresia is the name given to a malformation of the human rectum. In this case, the opening of the anus is missing or is not created correctly. Physicians also call an anal atresia an anorectal malformation. This refers to a malformation of the rectum that has existed since birth. The perforation of the anal fossa within the rectum is missing. This normally takes place in an embryo at a length of 3.5 centimeters. About 0.2 to 0.33 percent of all newborns are affected by anal atresia. In Germany, the anorectal malformation is seen in 130 to 150 babies each year. In most cases, anal atresia is diagnosed shortly after birth. In male children, the rectal malformation occurs more frequently than in girls.
Causes
In the case of anal atresia, the rectum does not form in the part of the body that is intended for it. Thus, a blind end of the bowel or a transition into a fistula may occur. The latter opens into the urinary bladder, urethra or female vagina. Likewise, advancement at the pelvic floor is possible. What causes anal atresia has not yet been found out. Primarily genetic factors are suspected as triggers. For example, the risk of anal atresia in siblings of children who already suffer from the malformation is 1:100 for the milder forms. For the other forms, the probability is put at 1:3000 to 1:5000. According to studies, two-thirds of all children affected by anal atresia show additional anomalies. Fifteen percent of all sufferers also suffer from genetic defects. These include, in particular, Down syndrome, Pätau syndrome and Edwards syndrome.
Symptoms, complaints and signs
Anal atresia can be divided into several forms. Thus, most affected individuals experience different fistula formations. Boys often suffer from anal atresia with a rectorurethral fistula. In contrast, girls usually present with a rectovestibular fistula, which occurs between the vestibule of the vagina and the rectum. Other fistula forms in boys include anouctane, anopenile, anoscrotal, rectovesical, rectoprostatic, and rectoperineal fistula. In females, anocutaneous fistulas and ectoperineal and rectovaginal fistulas still occur. Sometimes the classification of anal atresia is also based on the height of the malformation. A distinction is made between high, deep and intermediate forms. The higher the level of anal atresia, the greater the risk of additional malformations elsewhere in the body. A prominent feature of anal atresia is the absence of the anal opening at the anus. Sometimes fistulas are also noticeable after birth. In some cases, there is evacuation of stool or air through the female vagina or urethra. A noticeable symptom may also be a distended abdomen. Further malformations are seen in 50 to 60 percent of all children with the disease. The urinary region is particularly affected. In addition, malformations of the gastrointestinal tract, the spine or the heart frequently occur.
Diagnosis and course
It is not possible to reliably detect anal atresia before birth as part of prenatal diagnostics. The only option is to diagnose concomitant malformations. Even with the help of an ultrasound examination, anal atresia is difficult to detect. In most cases, the anorectal malformation is noticed by the absence of the anus or because the stool comes out in a place that is not intended for it. Following the initial finding, a perinaeal ultrasound examination is performed. In this way, the distance between the intended site of the anus and the rectal blind sac can be determined. If anal atresia is detected early, it can be treated well in most cases. Social continence can also be achieved with careful follow-up. By adolescent age, affected individuals are usually in a much better position to manage social continence.
Complications
A rather rare embryonic malformation is anal atresia. In this symptom, either the rectum and anus may be malformed or not formed.To date, there are no exact causes regarding the development of anal atresia within embryonic development. The malformation affects boys more than girls and shows additional variable fistula formations. Affected infants sometimes show other genetic anomalies, such as Down syndrome. Wide-ranging complication sequelae will accompany the child throughout life. Infants with anal atresia are examined in detail immediately after birth. The severity of the symptom and any other accompanying malformations are diagnosed. Medical measures are only initiated after the findings have been recorded. Surgical correction of anal atresia is performed during the first nine months of life. In the case of a severe form of the malformation, an artificial intestinal outlet as well as the actual anus is placed first and joined a little later. In the simplest case, complete correction can be performed immediately. The surgical procedure enables relative continence. The affected children can often only learn to control this better during their adolescence. The extent to which continence can be completely or only partially restored depends on the degree of the malformation. In some cases, patients suffer from psychological and physical secondary damage. They require a lifelong therapy plan and regular checkups.
Treatment and therapy
Treatment of anal atresia must always be performed surgically. There are differences in therapy when a fistula is present. If a fistula exists, the height of the malformation as well as its position play a decisive role. In addition, it is important to clarify whether the creation of an artificial bowel outlet is necessary before the corrective intervention. A fistula can first be widened in the direction of the perineum with a metal rod without any problems. If there is no dilatation of the bowel, there is no need for an artificial bowel outlet. It is necessary if the stool escapes through urine or from the vagina. If there is no fistula and the distance between the skin and the rectum is less than one centimeter, the surgical correction of anal atresia takes place without a colostomy. If the distance is longer, the first step is the creation of an artificial bowel outlet. During the operation, called posterior saggital ano-rectoplasty (PSARP), the surgeon detaches the stump of the rectum that does not open in the external direction and, if necessary, closes an existing fistula. Then the opening of the stump of the intestine takes place. By suturing, the surgeon also creates an anus on the outside. An artificial anus is later closed again so that the continuity of the bowel can be restored. As part of follow-up care, the child’s parents must regularly stretch the newly created anus for one year using a metal rod.
Outlook and prognosis
Thanks to modern surgical methods, anal atresia is usually easily correctable, as long as they are performed in time. In this regard, the required surgery usually leaves little damage, although the extent of any subsequent complications is determined by the form of anal atresia. For example, frequently existing fistulas between the intestinal tract and internal organs or the outside of the body are also decisive for the course of the surgery. An artificial bowel outlet or a correction of the bowel outlet using existing tissue, usually results in a functional bowel. If nutritional and bowel care measures are adhered to, the occurrence of complications – especially incontinence and constipation – can be reduced or prevented. If pelvic floor muscle and bowel training is practiced, the prognosis for fecal incontinence is good overall. The extent of agenesis (the absence) of other parts of the body in the lower trunk often determines the long-term prognosis. Missing or malformed parts of the spine occur in about half of all people affected by anal atresia. The long-term prognosis is determined by the resulting suffering and physical limitations. Because this form of malformation almost always occurs as a symptom of a disease-usually a syndrome-the symptoms of the particular disease must also be considered for prognosis.
Prevention
Because the causes of anal atresia are unknown and it is a congenital malformation, there are no effective preventive measures.
Follow-up care
Anal atresia is usually treated surgically. This usually prevents the typical symptoms from recurring.Only immediately after an operation do patients have to present to a doctor several times. The doctor monitors the healing process. Medication is also administered. Long-term aftercare is not required in the case of a positive surgical intervention. Anal resia cannot be prevented in advance. It is congenital and is usually diagnosed in young children. A physical examination is sufficient to detect it. An x-ray and MRI are ordered periodically. Follow-up care may be necessary, especially during puberty, with regard to the psychological condition of those affected, in order to reduce psychological suffering. This is because despite extensive continence, patients describe small smears in their underwear. Psychotherapy can help to learn how to deal with this in everyday life. If the surgical result is not satisfactory, another surgical intervention may be successful. However, this therapy always depends on the specific situation. Affected persons can also implement some aspects themselves that reduce the complications of constipation and incontinence. The choice of suitable foods can be learned. Intestinal flushing on the toilet also leads to an alleviation of discomfort.
Here’s what you can do yourself
Anal atresia always requires surgical treatment. The most important self-help measure is to clarify the discomfort quickly and make an appointment for surgical intervention promptly. Prior to surgery, the physician’s instructions must be followed. The physician will recommend an individual diet to the patient, which includes abstaining from stimulants and certain foods. Patients who regularly take medications or have allergies that have not previously been noted in the medical record should inform the physician. Since the hospital stay usually lasts several days, a sick note is usually also required. After the procedure, rest and bed rest are required. Since lying down can be uncomfortable for the first few days, a special hemorrhoid pillow must be used. To ensure that the healing process is positive, the wound must be well cared for. Precautions must be taken, especially during bowel movements. Which measures are necessary and useful in detail can best be answered by the doctor in charge. In general, a doctor must be seen at least two or three times after an operation to monitor the healing process and adjust medication if necessary. If discomfort or complications develop, medical advice is needed.
