Introduction:
Pylorus is a muscle between the stomach and the small intestine, which helps hold the food in the stomach until it is ready for the next digestive process. Pyloric stenosis is an uncommon condition in infants in which the pyloric muscle thickens and blocks the food from entering the small intestine. This condition is also known as gastric outlet obstruction and hypertrophic pyloric stenosis. It is the second most common problem in infants requiring surgery.
What Causes Pyloric Stenosis?
The exact cause of pyloric stenosis is not known. It is considered to be a multifactorial condition. It is caused by genetic and environmental factors.
What Are the Risk Factors for Pyloric Stenosis?
The factors which increase the risk of pyloric stenosis include:
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Sex: Firstborn male babies are at higher risk, which is less likely in girls.
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Race: It is more common among whites.
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Family History: An infant's risk of getting pyloric stenosis is three times higher if the mother has a history of pyloric stenosis.
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Smoking: Babies whose mothers smoked during pregnancy are at higher risk.
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Antibiotics: Babies who need antibiotics after birth and mothers who take antibiotics later in their pregnancy are at higher risk.
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Feeding: Babies drinking feeding formulas are at higher risk.
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Premature Birth: Babies born before the 37th week of pregnancy are at higher risk.
What Are the Symptoms of Pyloric Stenosis?
Babies are not usually born with pyloric stenosis. The thickening of the pylorus starts after birth. The symptoms of pyloric stenosis begin when the baby is three to five weeks old. It can take up to five months to become apparent. Pyloric stenosis affects every three out of 1000 babies born.
The signs and symptoms of pyloric stenosis include:
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Vomiting After Feeding: The baby has projectile vomiting - vomiting forcefully up to several feet away. The baby vomits either breast milk or milk formula. The vomiting is mild at first and gradually becomes severe. Sometimes the vomit may contain blood.
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Hunger: Babies often want to eat soon after vomiting.
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Dehydration: The baby may cry without tears or become lethargic. The baby’s urine output is also reduced, and will have fewer diaper changes.
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Constipation: Since the food does not reach the small intestine, there will be a change in bowel movements resulting in constipation.
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Weight Issues: Pyloric stenosis sometimes results in weight loss and weight gain.
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Stomach Contractions: There will be wave-like contractions seen in the baby's upper abdomen soon after feeding.
How to Diagnose Pyloric Stenosis?
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Physical Examination: The doctor feels an olive-shaped lump when examining the abdomen. That is the thickened pyloric muscle. Wave-like contractions (peristalsis) may be visible sometimes when examining the abdomen after feeding but before the baby starts vomiting.
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Blood Tests: Blood tests are done to check dehydration and electrolyte imbalances. Blood tests reveal low levels of potassium and chloride with an increased blood pH and high levels of bicarbonate.
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Ultrasound: It is a painless procedure in which a probe is placed over the belly and uses sound waves to create images of the thickened pylorus.
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Abdominal X-Rays: To see the pylorus if ultrasound results are not clear.
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Upper Gastrointestinal Series: This test is done when the physical examination and ultrasound do not show any abnormalities. The child drinks a liquid containing barium, and X-rays are taken when the liquid passes from the stomach to the small intestine. If it does not pass from the stomach, it indicates thickening of the pylorus.
What Is the Treatment of Pyloric Stenosis?
The treatment option for pyloric stenosis is surgery. The surgical procedure is called pyloromyotomy. The surgery is done on the same day of diagnosis. This surgery has a success rate of 100%. Very few mild cases are treated with medications. Intravenous and oral Atropine is used to treat pyloric stenosis. It has a success rate of 85% to 89%. It requires prolonged hospitalization and regular follow-up. This is an alternative for children who are contraindicated to anesthesia and whose parents are not ready for surgery.
Before starting the surgery, the baby is checked for dehydration and electrolyte imbalance. If present, fluid replacement is given. The child is given general anesthesia. The child will be asleep and do not feel any pain.
In the pyloromyotomy procedure, the surgeon cuts only through the outer layer of the thickened pylorus muscle allowing the inner layer to bulge out. This creates a way for the food to reach the small intestine.
Pyloromyotomy is often done using the laparoscopic method in which a small incision is made near the baby’s navel, and a laparoscope; and instruments are sent through the small incision. This is a minimally invasive procedure. This procedure has lesser pain and a quicker recovery rate and leaves a small scar. The procedure takes less than an hour.
After the surgery, the baby is given intravenous fluids for a few hours, and feeding is started within 12 hours to 24 hours. The baby might need feeding often, and some amount of vomiting may be present during the first few days after the surgery as the gastrointestinal tract settles.
In rare cases, the pylorus is still narrow even after the surgery; those babies need a second surgery.
What Are the Complications of Pyloric Stenosis?
Pyloric stenosis can lead to:
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Failure to grow and develop.
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Frequent vomiting may lead to dehydration and electrolyte imbalance.
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Frequent vomiting may irritate the baby’s stomach and cause mild bleeding.
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Rarely, it can result in jaundice which is the yellowing of the skin and whites of the eyes.
Conclusion:
Pyloric stenosis is a rare condition. Most babies do not have long-term problems after successful surgery for pyloric stenosis. They eat well, grow and thrive. If it is not correctly diagnosed and treated, the baby will not get enough nutrition and will becomes dehydrated.
