Anorectal malformations in boys

Posted onJune 19, 2020

Anal- skin (perineal) fistula

An anal- skin fistula is a low variant of the anomaly. The rectum is usually localized within the sphincter mechanism. Only its low part is shifted forward. Sometimes the fistula does not open on the perineum, but continues in the form of an epithelial passage along the midline, opening anywhere in the suture of the perineum, scrotum, or even at the base of the penis. The diagnosis is made on the basis of a routine examination of the perineum, without any additional examination methods.

Anal stenosis

Anal stenosis is a congenital narrowing of the anus and is often combined with a slight displacement of the latter anteriorly. At the same time, meconium stands out in the form of a narrow strip.

Anal membrane

In this rare form, deficiencies in the site of the anus are a thin membrane through which meconium is visible . Treatment is a resection of this membrane, or, if necessary, anoplasty .

Rectourethral fistula

A rectourethral fistula can open in the urethra in its lower (bulbar) time- tini or in the upper (prostatic) section. Directly above the fistula of the rectum and urethra combined by a common wall, is of great importance during operations. The rectum is usually dilated and surrounded by levator fibers behind and on the sides . Between it and the skin of the perineum are the striated muscles that form the muscle complex. When these fibers contract, the skin surrounding the anal fossa rises. On the level of the skin along the midline on each side of it are so-called paras-gitapni muscle volokna.Pri low urethral fistula usually well-developed muscles, buttocks, and the medial sulcus anal fossa. With a rectourethral fistula, meconium is often released from the urethra – a clear indication of the presence of this variant of the defect.

Rectovesical fistula

With this form of flaws, the rectum opens into the neck of the bladder. The prognosis in such cases is usually unsatisfactory, since the levator , the muscular complex and the external sphincter are underdeveloped. Buttocks are often deformed and have signs of dysgenesis . Almost the entire pelvis is also underdeveloped. The crotch is usually sagging, with obvious muscle underdevelopment. Disadvantages include 10% of all anal atresias.

Anorectal agenesis without fistula

In most patients with this rare form of malformation, the buttocks and muscles are well developed. The rectum ends about 2 cm from the skin of the perineum. The prognosis for bowel function is good. Between the rectum and the urethra, even in the absence of a fistula, there is a common thin wall (which is important to consider with surgical treatment).

Rectal atresia

This form of deficiency occurs in 1% of all anorectal abnormalities. At the same time, boys have an extremely rare variant of defects, the rectum may end blindly (atresia) or narrow stenosis. The upper section of the rectum is widened, while the lower section is a narrow anal canal 1-2 cm deep. Atresized sections of the rectum the intestines can be separated by a thin membrane, and sometimes a layer of fibrous tissue. Usually, in such cases, all the anatomical structures are available that are necessary to ensure the normal function of the locking mechanism and the prognosis, accordingly, is excellent. Since the anal canal such children well razovyu- TII , and the sensitivity of the anorectal area completely preserved. Muscle structures are usually almost completely normal. Clinic of atresia of the rectum and anorectal agenesis General condition of the newborn on the first day remains satisfactory. From the second day symptoms of intestinal obstruction begin. Bloating builds up. The child becomes restless, crying. Vomiting appears first eaten food, and then meconium . Symptoms of intestinal obstruction progressively increase, and on 4-6 days from birth, if surgical care is not provided, the child dies. Diagnosis of rectal atresia and anorectal anagenesis. When diagnosing, it is important to decide the level of rectal placement.

The following methods are used:

  • survey and sensing of the anus.
  • Reception of Wangensteen – Kakovich ( invertogram ) – examination of a child in front of the X-ray machine in a suspended position upside down by legs. The distance between the gas bubble in the rectum and perineum skin give the level of occurrence of colorectal
  • puncture method of diagnosis with MB. Sitkovskiy – punktuyut crotch needle until IU The horse with the blind end of the rectum.

Then through the same needle is introduced iodo-LIPOL followed radiography distal colon kishki.Pervichnaya diagnosis of anorectal diseases in boys and the choice of method lecheniyaNovorozhdenny with anorectal anomaly: Acad disadvantages clinically clear (80-90%): crotch fistula, the fistula along the crotch seam, anal stenosis, anal membrane – minimum rear sagittal anorektoplastika newborn without colostomy “slack crotch”. meconium in the urine, the air in the bladder – colostomy – 4-8 weeks to exclude ities Leica Geosystems defects, ensure the normal development of the child, and then – holding the back sagittal anorektoplastika

Carrying invertogramy :

  • If diastasis less than 1 cm – the minimum posterior sagittal anorektoplastika newborn without colostomy .
  • If diastasis is more than 1 cm – colostomy – after 4-8 weeks, exclude concomitant defects, verify the normal development of the child, then perform posterior sagittal anorectoplasty.

In more than 80% of cases, examination of the perineum allows you to clearly determine the type of defect and decide on whether colostomy overlay . All those defects that are traditionally considered “low” require perineal anoplasty (minimal posterior sagittal anoplasty ) without protective colostomy .

These include: a perineal fistula with a subepithelial passage (with or without a) along the midline suture of the perineum, anal stenosis and an anal membrane. The presence of a sagging perineum or discharge with urine meconium is an indication for colostomy , which in such cases promotes intestinal decompression and ensures successful future suture healing after the main operation. After applying the colostomy, the child is discharged home. If the child develops well and does not have concomitant abnormalities (heart or gastrointestinal tract) requiring treatment, then re-hospitalization for posterior sagittal anorectoplasty is performed at the age of 1-2 months. Surgery in such young children requires more experience, while in older patients, surgery for anorectal malformations is no longer so complicated. That is why patients with such abnormalities are usually operated on at a later date (at the age of, as a rule, about 1 year).

The main intervention at the age of 1 month has important advantages. So, the child lives with a colostomy for a short period of time, the difference in the diameters of the proximal and distal intestines is not so pronounced in the closure of the colostomy , it is easier to carry out vascularization and significantly less psychological trauma to the child during various painful manipulations in the anorectal zone. But intervention in young children is possible only if the surgeon has the appropriate experience. In cases where urine diversion is indicated, it is necessary to conduct a urological examination before applying the colostomy . A colostomy and urine diversion should be performed simultaneously. Sometimes , according to clinical data, the surgeon cannot decide on the application of a colostomy . In such cases (less than 20% of all anorectal malformations in boys), an X-ray examination is indicated – invertography (a picture in the upside down position with a label in place of the missing anus).

A simple method is to study in lateral position when the child is placed face down and the pelvis is to be lifted . Examination should be carried out 16-24 hours after birth. By this time, due to insufficient filling of the intestinal loops and low intraluminal pressure, the air does not reach the distal intestines and therefore the results of the study cannot be reliable. In addition, meconium may come out of the urethra during the waiting period , which facilitates identification of the type of anomaly and eliminates the need for x-ray examination . If the height of the atresia, according to x-ray, more than 1 cm, then a colostomy is indicated . If the distance is less than 1 cm, then the defect can be regarded as low and then perineal surgery without protective colostomy is indicated .

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