Congenital colonic stenosis and atresia

　　The etiology of congenital colonic stenosis and atresia includes the following two types:

　　1. Incomplete intestinal cavitation during the embryonic period

　　In the past, according to the Tandier theory, it was believed that before the 5th week of embryonic development, the digestive tract lumen had a complete intestinal tract covered by epithelial cells. After that, the growth of epithelial cells was extremely fast, and the lumen was occluded by the proliferation of epithelial cells, known as the solid phase. Later, cavities appeared, forming cystic spaces that were interconnected, and the lumen was reconnected at 12 weeks of embryonic development. If the cavities were not completely connected, atresia or stenosis would form.

　　2. The fetal mesenteric blood circulation is obstructed due to damage

　　Abnormalities or occlusions of mesenteric vascular branches, and fetal abdominal cavity infection can lead to colonic atresia and stenosis. L

　　Colonic atresia and stenosis often complicate with intestinal perforation or diffuse peritonitis. Intestinal perforation refers to the process in which the intestinal wall lesions penetrate and cause the overflow of intestinal contents into the peritoneal cavity. It causes severe diffuse peritonitis, mainly manifested as severe abdominal pain, abdominal distension, and signs and symptoms of peritonitis. In severe cases, it can lead to shock and death.

　　In the history of colonic atresia, there may be polyhydramnios during the mother's pregnancy. Newborns do not pass meconium within 48 hours after birth, and symptoms such as abdominal distension and vomiting appear. The vomit contains bile. After feeding, there is a low-position complete intestinal obstruction. Some children have a history of normal meconium within 1-2 days after birth.

　　The symptoms of colonic stenosis are related to the degree of stenosis. Severe stenosis manifests similarly to atresia. The symptoms of mild stenosis are mild and the course is long. Patients may begin to gradually appear symptoms of low-position incomplete intestinal obstruction within a few weeks after birth. Symptoms after feeding are progressive. Vomiting is intermittent. The vomit is mostly milk and food residue, and occasionally bile. Patients have abdominal distension, visible intestinal loops, and hyperactive bowel sounds. Defecation is difficult, and feces are often loose or thin strips. Children often have malnutrition and anemia and are prone to misdiagnosis as congenital megacolon.

　　Congenital colonic stenosis and atresia belong to congenital malformations. The prevention of congenital malformations is divided into the following aspects:

　　1. Pregnant women should avoid fever and colds in the early stages of pregnancy. High fever causing fetal malformation is also related to the sensitivity of pregnant women to high fever and other factors.

　　2. Pregnant women should avoid close contact with cats and dogs. Bacteria-carrying cats are also a significant source of infectious diseases that can cause fetal malformation.

　　3. Pregnant women should avoid wearing heavy makeup every day. Toxic substances such as arsenic, lead, and mercury in cosmetics can affect the normal development of the fetus.

　　4. Pregnant women should avoid pregnancy-related stress. When pregnant women are emotionally stressed, adrenal cortical hormones may hinder the integration of embryonic tissue. If it occurs in the first three months of pregnancy, it can cause fetal malformation.

　　6. Pregnant women should avoid drinking alcohol. Alcohol can pass through the placenta to the developing embryo, causing severe harm to the fetus.

　　The auxiliary examinations for congenital colonic stenosis and atresia mainly include the following:

　　1. Abdominal X-ray

　　Children with colonic atresia often have multiple dilated intestinal loops with liquid-gas levels. The presence of a larger liquid-gas level in a highly dilated loop is often a sign that suggests transverse colon atresia.

　　2. Ileocolonoscopy

　　Ileocolonoscopy is of great significance in distinguishing colonic atresia, congenital megacolon, meconium ileus, and small bowel atresia. In colonic atresia, barium enema can show immature colon and incomplete colonic filling. In colonic stenosis, the contrast medium can be seen from the distal small and thin colon to the proximal dilated colon.

　　3. Fiberoptic colonoscopy or sigmoidoscopy

　　Fiberoptic colonoscopy or sigmoidoscopy can exclude intestinal stenosis caused by other colonic lesions and can observe the condition of the distal stenotic orifice.

　　Patients with congenital narrowing and atresia of the colon should eat light and nutritious liquid and semi-liquid foods. Eating more foods rich in high protein is beneficial for wound healing. Supplementing a variety of vitamins can eat more fresh vegetables and fruits. In addition, patients should pay attention not to eat high-fat foods such as animal internal organs, wind eel, crucian carp roe, crab roe, clam, eggs, fish liver oil, etc., and pork lard, butter, fried dough sticks should be strictly avoided. It is advisable to add less oil when making soup. Seafood such as sea fish, sea cucumber, seaweed, nori should be avoided.

　　Congenital narrowing and atresia of the colon should be immediately treated surgically after early diagnosis. The preoperative preparation is the same as that for small intestine atresia, such as warming, gastrointestinal decompression, correction of dehydration and electrolyte imbalance, antibiotic application, blood preparation, etc. The surgical plan should be formulated according to the child's overall condition, the presence or absence of concurrent malformations, the location and nature of the atresia. Children with good conditions, especially those with right colon atresia above the splenic flexure, can undergo primary ileocolic or end-to-end or end-to-side anastomosis after resection of the atresia and proximal dilated intestinal tract. In late cases with severe malformations and colonic atresia below the splenic flexure, a colostomy should be performed first, and then a colonic end-to-end anastomosis should be performed after 6 to 12 months to restore intestinal patency. Due to fibrosis of the colonic wall tissue, longitudinal incision and transverse suture or septum resection often cannot relieve obstruction and cause recurrence of symptoms, therefore, the surgery should be resected after the narrowed segment and dilated intestinal tract and then perform end-to-end anastomosis. If it is difficult to operate in the pelvic cavity, rectal colonic pull-through anastomosis (Swenson method) or rectal posterior colonic pull-through side-to-side anastomosis (Duhamel method) can be performed.