Pyloric Stenosis

Pyloric stenosis is a condition in which the pylorus muscles, responsible for regulating the passage of food from the stomach to the small intestine, become abnormally thickened.

This thickening creates a blockage, making it difficult for food to pass through. This leads to forceful vomiting, which can cause dehydration and failure to thrive.

Pyloric stenosis primarily affects infants, generally within the first few weeks of life, and is a common cause of gastrointestinal obstruction in this age group.

An ultrasound is usually used to diagnose pyloric stenosis. Surgery is typically required to treat pyloric stenosis.

What is the pylorus?

The pylorus is the muscle ring between the stomach and small intestine. The pylorus muscle opens and closes during digestion. This allows partially digested food and other stomach contents to pass through the stomach to the small intestine.

Stenosis means an abnormal narrowing of a passage or opening in the body.

Pyloric stenosis is when the pylorus muscle is abnormally narrow.

Symptoms

Common symptoms of pyloric stenosis include:

• Projectile vomiting after feedings: Infants with pyloric stenosis often experience forceful vomiting after eating.
• Persistent hunger and feeding issues: Despite vomiting, babies remain hungry and may continuously feed without satisfaction.
• Dehydration: Due to frequent vomiting, infants can become dehydrated, showing signs like dry mouth and fewer wet diapers.
• Weight loss or poor weight gain: Infants may struggle to gain weight or might lose weight due to inadequate nutrient absorption.
• Constipation: Dehydration and reduced food intake can result in infrequent bowel movements.
• Visible stomach contractions: You might notice rippling movements across the baby’s abdomen as the stomach muscles work hard to push food through the narrowed pylorus.

Risk factors

Understanding the risk factors associated with pyloric stenosis can help in early identification and prompt treatment. While the exact cause of pyloric stenosis remains unknown, certain factors are known to increase the likelihood of developing this condition. These include genetic, environmental and demographic influences. Risk factors include:

• Family history of pyloric stenosis
• Born prematurely
• The parent is a tobacco user
• Gender (more prevalent in boys)
• Antibiotic use in early life
• Certain genetic disorders

Complications

If pyloric stenosis is left untreated, several serious complications can arise due to the persistent obstruction and resultant nutritional and fluid imbalances. These complications include:

• Severe dehydration: Constant vomiting can lead to significant fluid loss, reducing the body’s ability to maintain proper hydration levels. This can result in symptoms such as dry skin, sunken eyes and lethargy.
• Imbalance in electrolytes: Vomiting can cause significant electrolyte imbalances, particularly low levels of potassium and sodium, which are critical for various bodily functions. This imbalance can lead to muscle weakness, irregular heartbeat and other serious conditions.
• Weight loss and malnutrition: With the obstruction of food passage, infants are unable to retain and absorb necessary nutrients, leading to poor growth, weight loss and potentially severe malnutrition.
• Failure to thrive: Untreated pyloric stenosis can result in the baby not meeting developmental milestones such as gaining weight and growing in length, compromising overall health and development.
• Metabolic alkalosis: Prolonged vomiting can lead to a condition where the body’s pH becomes too alkaline. This metabolic imbalance can cause complications including tetany (muscle spasms), seizures and altered mental state.
• Worsening vomiting: As the condition progresses, vomiting may become more frequent and forceful, increasing the risk of aspiration, where gastric contents enter the lungs, potentially leading to pneumonia or other respiratory issues.

Timely medical intervention is crucial to prevent these complications. At WashU Medicine, we prioritize rapid diagnosis and effective treatment to ensure the best possible outcomes for infants with pyloric stenosis.

Screening and diagnosis

Early detection is crucial for effective management and a swift recovery. If pyloric stenosis is suspected, your pediatrician might recommend an ultrasound to confirm the diagnosis. Other diagnostic tests may include blood tests to check for dehydration and electrolyte imbalances.

Treatment

Surgery is necessary to treat pyloric stenosis. The surgical treatment for pyloric stenosis is called pyloromyotomy.

In pyloromyotomy, the surgeon cuts into the pylorus muscle and uses a device to spread the muscle apart. The pylorus still works, but is looser, allowing food to pass from the stomach to the small intestine.

At WashU Medicine, our pediatric surgeons often perform pyloromyotomy through a minimally invasive approach called laparoscopic surgery. Minimally invasive surgery typically has a shorter recovery time. When needed, our experts can also perform pyloromyotomy as an open procedure.

Post-operative care and support

After surgery, your child will be monitored to ensure they start feeding normally, gain adequate weight and remain hydrated. Our team will provide extensive support and guidelines to help in the recovery process.

At WashU Medicine, our pediatric surgery team is equipped with unparalleled expertise in treating pyloric stenosis.

We spearhead advanced research and employ evidence-based practices to ensure that your child receives the best possible care.

Our state-of-the-art facilities and compassionate health care providers are committed to guiding you through diagnosis, treatment and aftercare with confidence and care.

Prevention and long-term outlook

Currently, there is no definitive way to prevent pyloric stenosis.

However, early identification and treatment significantly improve outcomes.

If treated promptly with pyloromyotomy, most children recover completely with no long-term complications. Rarely, the condition may recur (come back), necessitating further medical evaluation.

We are here to provide you with the highest level of care and support throughout the entire journey.