Congenital intestinal atresia

　　Congenital intestinal atresia often complicates with dehydration, acidosis, aspiration pneumonia, and when there is intestinal perforation, it may also complicate with peritonitis, pneumoperitoneum, shock, etc. It often also complicates with other congenital malformations: such as biliary atresia, esophageal atresia, umbilical hernia, anal and rectal atresia, Meckel diverticulum, intestinal duplication anomaly, and other gastrointestinal malformations; polydactyly (polydactylism), hypospadias, horseshoe kidney, and other urinary system malformations; congenital heart disease and other cardiovascular malformations. It is rare for congenital intestinal atresia to be accompanied by Down syndrome.

　　Congenital intestinal atresia, regardless of the height of the atresia, is a complete intestinal obstruction, mainly manifested as:

　　1. Vomiting

　　Children with high atresia vomit for the first time after birth when they are fed, and the vomiting gradually becomes more severe and frequent. The vomit contains water, milk, and bile. In ileal and colonic atresia, vomiting usually occurs 2 to 3 days after birth. The vomit contains bile and feces, and the frequency of vomiting is not as frequent as in high atresia.

　　2. Abdominal distension

　　Children with high atresia have distension of the upper abdomen, visible gastric shape, and the distension disappears after severe vomiting. Low atresia shows generalized abdominal distension, hyperactive bowel sounds, or visible intestinal shape.

　　3. Defecation condition

　　The newborn does not pass meconium or only passes a small amount of gray-green mucoid material. Children with high intestinal atresia repeatedly vomit, and quickly develop dehydration, electrolyte imbalance, and acidosis. In the late stage of low intestinal atresia, due to the extreme dilation of the intestinal tract, perforation may occur, leading to peritonitis.

　　Pre-marital physical examination plays a positive role in preventing birth defects, the extent of which depends on the items and content of the examination, mainly including serological tests (such as hepatitis B virus, syphilis spirochete, HIV), reproductive system examination (such as screening for cervical inflammation), general physical examination (such as blood pressure, electrocardiogram), and inquiries about family history of diseases and personal medical history, and doing genetic counseling work well.

　　Pregnant women should try to avoid harmful factors, including staying away from smoke, alcohol, drugs, radiation, pesticides, noise, volatile harmful gases, and toxic and harmful heavy metals. During the prenatal health care process of pregnancy, systematic screening for birth defects should be carried out, including regular ultrasound examination, serological screening, and if necessary, chromosomal examination to take effective diagnostic and treatment measures.

　　Routine blood and blood biochemical tests are performed for congenital intestinal atresia. In cases of peritonitis and pneumonia, there is infectious blood picture, with increased white blood cells, decreased hemoglobin, and decreased platelets. Blood biochemical tests include blood sodium, potassium, chloride, calcium, and blood pH value, which often show water and electrolyte imbalance, and may appear alkalosis. There may be signs of renal dysfunction, such as increased creatinine and blood urea nitrogen.

　　In the past, many people emphasized the use of the Farber test to check for the absence of keratinized epithelial cells and fetal hair in meconium to diagnose intestinal atresia, which has diagnostic value for those who form intestinal atresia within 3 months of gestation; however, for intestinal atresia caused by mechanical or vascular factors in the middle and late stages of gestation, it has no diagnostic significance, as the keratinized epithelium has already descended to the distal end of the atresia. In recent years, it has been rarely used in clinical practice, as the diagnosis of intestinal atresia is generally not difficult based on clinical and X-ray examination. In addition, the test is not completely accurate.

　　1. X-ray examination

　　X-ray abdominal films are of great value in diagnosing intestinal atresia and stenosis. High intestinal atresia can show the 'three bubble sign' or large fluid level and small fluid level on the erect abdominal film, that is, 1 large fluid level (stomach) and 3 to 4 small fluid levels (dilated jejunum), while the lower abdomen shows no gas shadow or more dilated intestinal loops. The erect abdominal film of low intestinal atresia shows multiple fluid levels and dilated intestinal loops, but there is no gas shadow in the colon; the caliber of other dilated intestinal loops is mostly uniform; on the lateral film, there is no gas in the colon and rectum, which is different from paralytic ileus.

　　2. X-ray barium examination

　　It is not appropriate to perform barium meal examination on children with intestinal atresia, as there is a risk of aspiration pneumonia. However, it is necessary to perform barium enema examination in atypical cases in clinical practice; not only can the diagnosis of intestinal atresia be determined according to the fetal type of colon, and determine whether the colon is atretic, but it can also exclude congenital megacolon or intestinal malrotation.

　　Barium enema under a fluorescent screen or film shows a small colon, with a diameter of about 5mm. In addition, barium enema can differentiate intestinal malrotation and congenital megacolon.

　　In cases of intestinal stenosis, it is often necessary to perform barium meal examination to make the diagnosis clear. Under fluoroscopy, barium can be seen to accumulate at the blocked site, with only a small amount of barium passing through the stenotic segment into the distal intestinal cavity.

　　3. Prenatal B-ultrasound scan

　　It is of great value for diagnosing fetal small intestinal atresia. High-level jejunal atresia shows a long liquid area extending from the stomach to the proximal jejunum or several dilated jejunal liquid areas detected in the upper abdominal cavity of the fetus.

　　Children with congenital intestinal atresia should be strengthened in feeding and care, and early surgical treatment should be performed. The diet of the mothers should be light, with a reasonable diet, attention should be paid to nutritional balance, more vegetables and fruits should be eaten, and spicy and stimulating foods should be avoided.

　　Congenital intestinal atresia has no hope of survival without surgery. The timing of surgical treatment, the preparation before surgery, and the care before and after surgery, such as keeping warm, gastrointestinal decompression, correcting dehydration, intravenous nutrition, and cleaning oral secretions, directly affect the prognosis. The following surgical methods can be selected according to the different types of atresia:

　　1. For intestinal resection and anastomosis, 10-15 cm of the proximal and distal ends of the atretic intestinal tube are resected for end-to-end anastomosis.

　　2. In some cases, the proximal intestinal tube may be overly thickened and expanded during end-to-side anastomosis and fistulation, while the distal intestinal tube is small. End-to-side anastomosis and distal fistulation surgery (Bishop-Koop method) or side-to-side anastomosis and proximal fistulation surgery (Santulli method) can be performed.

　　3. For elective intestinal anastomosis with low intestinal atresia and poor general condition, where it is not possible to perform a primary intestinal resection and anastomosis, the proximal and distal intestinal tubes can be fistulated, and the distal intestinal tube can be dilated, and the intestinal anastomosis can be performed at a later date. However, newborns often cannot tolerate the loss of intestinal fluid, which is prone to produce hyponatremia and electrolyte imbalance, and it is best to strive for primary anastomosis without fistula.