Congenital pyloric hypertrophic stenosis

Many congenital diseases do not have obvious symptoms when the baby is just born. For example, in the case of congenital pyloric hypertrophic stenosis, the newborn baby behaves normally in all aspects, whether it is feeding, defecation, etc., they are no different from normal babies. However, around the third week, the baby will begin to show symptoms, starting with vomiting, which slowly progresses to projectile vomiting, and at the same time, there will be a mass in the abdomen.

【Clinical manifestations】

The main manifestations are symptoms of high-level gastrointestinal obstruction, such as vomiting, visible gastric peristaltic waves in the upper abdomen, and palpable enlarged pyloric mass.

1. Vomiting is the first symptom of this disease. Generally, children with congenital hypertrophic pyloric stenosis are asymptomatic after birth, and their breastfeeding, bowel movements and urination are normal. Vomiting usually occurs 2 to 3 weeks after birth. In a few cases, vomiting occurs immediately after birth, and occasionally as late as 7 to 8 weeks. Premature infants tend to develop the disease late. At first, the baby would vomit up milk after feeding and vomit occasionally. The frequency of vomiting would gradually increase until he would vomit every time after feeding. Vomiting usually occurs within a few minutes after feeding, and changes from general vomiting to projectile vomiting. In severe cases, it can spray several feet away, often from the mouth and nostrils. Vomiting in immature infants with pyloric stenosis is often atypical, and is general vomiting without projectile vomiting. The vomitus is milk and gastric juice or milk curds, and does not contain bile. When vomiting is severe, it may be brown (accounting for 3% to 5%). Later, due to the gradual expansion and relaxation of the stomach, milk is retained in the stomach for a longer time, and the number of vomiting seems to be reduced compared to before. Sometimes there is no vomiting after 1-2 feedings, but the next time the amount of milk vomited is often more than the amount taken in. The two amounts are vomited out together, containing more milk curds and a sour taste. Although vomiting is frequent, the baby still has a strong appetite after vomiting and shows a sense of hunger. If fed again, he can suck as usual. For those with severe vomiting, the stool decreases, and bowel movements are only once every few days. The stool is dry and hard. Urine output also decreases.

2. Gastric motility wave abdominal examination shows a bulging upper abdomen and a flat and soft lower abdomen. About 95% of children can see gastric peristaltic waves in the upper abdomen, which start from under the left rib, move to the right upper abdomen, and then disappear. Sometimes two waves can be seen appearing one after another, especially after feeding. Sometimes, tapping the abdominal wall gently with your hands can also cause gastric peristaltic waves to appear. Gastric peristaltic waves are a common but not specific sign of congenital hypertrophic pyloric stenosis and are usually visible during feeding or after a full meal. It can also be seen in premature infants under normal circumstances and cannot be used as a basis for diagnosis.

3. Abdominal mass: The olive-like mass felt in the right upper abdomen is a specific sign of pyloric stenosis. If it can be felt and combined with a history of typical vomiting, the diagnosis can be confirmed. However, such lumps are not often easy to palpate, and the detection rate of the lumps is related to the experience and especially the patience of the examiner. The best time to check is when the child is asleep or in the mother's arms while feeding, as the child sucks hard and the abdominal wall is relaxed. The doctor stands on the right side of the child and gently massages deep into the outer edge of the rectus abdominis muscle under the ribs in the right upper abdomen with the tip of his middle finger. He can feel an olive-shaped, hard pyloric mass. Sometimes the lump is located deep and covered by the liver, making it difficult to feel. In this case, place your left hand behind the child to lift him up slightly, use your right middle finger to push the edge of the liver upwards and then feel deeper. As long as you examine repeatedly patiently and carefully, the lump can be felt in almost all cases. Premature babies have poorly developed abdominal muscles and thin abdominal walls, making them easier to touch.

4. Dehydration and malnutrition Due to progressive vomiting and insufficient intake, dehydration often occurs. There is no weight gain in the initial stage, but then it drops rapidly and the patient becomes thinner day by day. If a baby is not treated within 2 to 3 weeks of the onset of the disease, his weight may be about 20% lower than his birth weight, and he may appear malnourished. Subcutaneous fat decreases, the skin becomes loose, dry, wrinkled, and loses elasticity. The anterior fontanelle and eye sockets become sunken, and cheek fat disappears, giving the face an elderly appearance.

5. Alkali poisoning: Due to long-term vomiting, a large amount of gastric acid and potassium ions are lost, which can cause hypochloride and hypokalemia alkali poisoning, the clinical manifestations of which are shallow and slow breathing. Due to the decrease of free calcium ions in the blood, hypocalcemic convulsions may occur, manifested as hand and foot cramps, laryngeal spasms, tonic convulsions, etc. However, if the child is severely dehydrated and has low renal function, acidic metabolites will be retained in the body and some alkaline substances will be neutralized, so obvious alkali poisoning is not common. A few advanced cases even present with metabolic acidosis, manifested by mental depression, anorexia, and pale complexion.

6. Jaundice: 2% to 3% of children develop jaundice, mainly due to increased indirect bilirubin, which gradually disappears after surgery. The causes of jaundice are related to insufficient calories, dehydration, and acidosis affecting the glucuronyl transferase activity of liver cells, and delayed stool excretion increasing enterohepatic circulation; sometimes there is an increase in direct bilirubin, which is related to the hypertrophic pylorus compressing the common bile duct to produce mechanical obstruction; autonomic nervous system imbalance causes spasm of the common bile duct; dehydration causes bile concentration and congestion, etc.