The stomach is part of the digestive system which extends from the end of the Esophagus to the start of the duodenum. The stomach is divided into four parts which begin at the Gastric cardio. Each part of the stomach has different cells and functions.
- Cardia: Cardia is the part of the stomach where the Esophagus meets the stomach. Oesophageal sphincter or the cardiac sphincter regulates the passage of the foods in the stomach
- Fundus: The part of the stomach next to the cardia is fundus. It lies below the diaphragm.
- Body: It is the largest part of the stomach sandwiched between the fundus and pylorus.
- Pylorus: Part of the stomach, which facilitates the passage of the gastric contents into the duodenum.Pylorus has two parts named Pyloric Antrum and the Pyloric canal. Pyloric canal contains sphincter, which facilitates the passage of food from the stomach to the duodenum.
Definition of Pyloric stenosis
Pyloric stenosis means narrowing of the pylorus due to hyperplasia and hypertrophy (thickening) of the muscular layers of the pylorus. It is one of the major causes of the gastric outlet obstruction and is seen in the newborns (congenital hypertrophic pyloric stenosis) and the people having gastric carcinoma. Pyloric prevents food from moving into the intestine and the food which are retained in the stomach causes the infants to vomit.
Pyloric is commonly seen after 4th weeks of birth. It is 4 times more common in males than females. The incidence of occurrence of congenital hypertrophic pyloric stenosis is documented to be common in a firstborn child.
Cause of infantile hypertrophic pyloric stenosis
The exact cause of the infantile hypertrophic pyloric stenosis is still an unsolved mystery, but researchers have demonstrated a strong link between some factors listed below.
– The incidence of infantile hypertrophic pyloric stenosis is very high in monozygotic twins.
– Genetic abnormalities such as IPHS 1 in which the production of the neuronal nitric oxide synthase is reduced is found to restrict the relaxation of the pyloric muscles.
-The presence of high amount of the parietal cells (which secretes the gastric acid) has a strong association with the occurrence of infantile hypertrophic pyloric stenosis.
– Use of antibiotics such as erythromycin in newly born babies before 2 weeks of life carries a higher risk for development of the congenital hypertrophic pyloric stenosis.
– A child born from women who smoked during the pregnancy is at high risk.
– Preterm babies are at higher risk than the full term babies.
-Some races are at high for pyloric stenosis.
-Europeans are at higher risk than the Asians.
Signs and Symptoms of infantile hypertrophic Pyloric stenosis
Symptoms of pyloric stenosis usually appear four weeks after birth. Pyloric stenosis is rare in infants after the age of three months.
- The baby vomits breast milk or formula several feet away also known as projectile vomiting soon after feeding. Vomiting is mild at first, but after the appearance of the vomiting as symptom, it becomes more severe as the pylorus opening narrows. The color of the vomit is yellow colored due to the action of the gastric acid in the breast milk.
- Immediately after vomiting the baby is usually hungry.
- As food does not pass through the pylorus to reach the intestine, they also present with Constipation.
- Weight loss.
- Wave-like contractions called peristalsis is seen across the upper abdomen soon after breastfeeding but before child vomits.
- Contraction of the muscles of the stomach while trying to push the food through the narrowed pylorus causes the peristaltic waves.
Signs of dehydration in the infants include depression of the fontanelle, absence of tear film, passing urine in low amounts, crying without tears, etc.
- Distended stomach and smooth ovoid mass just below the costal margin is seen.
- Pylorus may be felt in an epigastric region on some occasions while palpating the abdomen.
- Growth failure
- Dehydration resulting from excessive vomiting.
- Electrolyte imbalance
- Gastric irritation which may lead to ulcer and bleeding.
- In rare cases, jaundice may occur.
Diagnosis is made on the basis of symptoms and the signs.Following investigations are done to confirm the diagnosis and to help in the treatment:
- Ultrasonography of the whole abdomen
The best choice of investigation is ultrasonography of the whole abdomen because it directly visualizes the pylorus. The hypertrophied muscles are hypoechoic while the central mucosa is hyperechoic on USG.
- Plain X-ray of the whole abdomen
Distended abdomen with a minimum amount of the intestinal gas can be seen on plain X-ray of the abdomen.These findings are nonspecific.
- Barium meal X-ray
The patient is asked to the intake Radioactive element containing fluid then the series of X-ray is taken. The findings are delayed gastric emptying, peristaltic wave, elongated pylorus with a narrow lumen, pylorus indenting the lumen of the pyloric canal etc.
4. Blood tests
Blood tests are done to see the electrolyte levels, renal function test which is affected by vomiting and dehydration.
Pyloric stenosis is not self-limited and should be corrected by an operation.The operation involves cutting of the muscle fibers of enlarged pyloric muscle to widen the opening into the intestine.This process is called pyloromyotomy. Preoperative management includes an admission of the infant to the hospital and giving intravenous fluids. Stopping breastfeeding as well as formulations. Blood examinations for dehydration and electrolyte abnormalities. The operation is done when the infant’s electrolyte levels are normal and the dehydration is corrected. A pyloromyotomy can be also be done using a small telescope or is performed making a very small incision in the abdomen known as Open pyloromyotomy. Endoscopic balloon dilatation of the pyloric stenosis can also be done if the patient is not fit for operation. Recurrences are very high in endoscopic balloon dilatation. Blood loss is very minimal and rarely requires a blood transfusion. After the operation, the chances of developing pyloric stenosis again is almost zero. The patient may be discharged in 2 to 3 days.