What is Pyloric Stenosis?
Pyloric stenosis, also called infantile hypertrophic pyloric stenosis (IHPS), is a rare condition in babies. It involves the thickening of the muscles in a part of the stomach known as the pylorus, causing a blockage between the stomach and the intestine. Most babies are born healthy, but between 3 to 6 weeks old, they start showing symptoms like intense, forceful vomiting, which can result in dehydration and weight loss.
Doctors specializing in medical imaging, known as radiologists, are vital in detecting this condition. The main treatment for this condition is surgery.
What Causes Pyloric Stenosis?
The exact cause of a condition in infants known as infantile hypertrophic pyloric stenosis is not fully understood. This condition involves the narrowing of the opening from the stomach into the intestines, making it harder for food to pass through. Some studies have found that infants who were treated with a type of antibiotics called macrolides had an increased chance of developing this condition.
Taking a specific antibiotic called erythromycin after birth has also been linked with a higher risk for the condition. Other things that could increase the risk include being fed from a bottle, being born prematurely, being delivered by cesarean section, and being the first-born child (this applies to 30% to 40% of cases).
If the mother smoked heavily during pregnancy, the risk of the baby developing this condition could increase by 1.5 to 2 times.
Risk Factors and Frequency for Pyloric Stenosis
Pyloric stenosis is a condition that impacts 2 to 5 out of every 1,000 newborn babies each year. It’s seen more often in males, with about four males getting it for every one female. While it does tend to run in families, the exact way it is passed down isn’t straightforward. It also happens to be more prevalent in white populations compared to Indian, Asian, and Black populations.
- Pyloric stenosis affects 2 to 5 out of every 1,000 newborns per year.
- It’s more common in males, with a ratio of 4 males for every 1 female affected.
- Family history can play a role in the likelihood of getting it, although the pattern is complex and not fully understood.
- White populations are more likely to experience this condition.
- It is less frequent in Indian, Asian, and Black populations.
- The incidence among different racial groups varies: about 2.4 in 1000 for whites, 1.8 in Hispanics, 0.7 in blacks, and 0.6 in Asians.
Signs and Symptoms of Pyloric Stenosis
Pyloric stenosis, a condition in infants, often leads to strong, non-bilious vomiting. This vomiting can be intermittent or happen after every feeding. About 60% to 80% of infants with this condition might have a firm, non-sensitive area in their upper right abdomen. It’s often described as feeling like an “olive”. Additionally, medical professionals might see unusual movements in the stomach area.
Dehydration is common in these infants and can be recognized by signs such as a sunken soft spot on the head, dry mouth, reduced tear production, poor skin elasticity, and lethargy.
Another sign of pyloric stenosis is an imbalance of electrolytes, specifically low chloride and potassium levels resulting in metabolic alkalosis. However, due to early diagnosis nowadays, less than half of the cases show these abnormalities. Dehydration may result in either too much or too little sodium in the blood, both of which can lead to kidney issues. Some infants may also have high levels of unconjugated bilirubin.
- Strong, non-bilious vomiting
- Firm, non-sensitive area in the upper right abdomen
- Unusual stomach movements
- Signs of dehydration: sunken soft spot, dry mouth, reduced tear production, poor skin elasticity, lethargy
- Imbalance of electrolytes
- Alterations in sodium levels due to dehydration
- High levels of unconjugated bilirubin
Testing for Pyloric Stenosis
Babies who regularly throw up violently due to a condition known as pyloric stenosis can experience dangerously low levels of chloride and potassium, two crucial elements for the body. This is viewed as the main biochemical abnormality for this condition.
Doctors use a method called ultrasonography, which uses sound waves to create images of the body’s interior, to diagnose this condition. This method is dependable, highly sensitive, and can easily be done, however, it requires an experienced user to conduct accurately. If the ultrasound reveals a thickness in the pyloric wall of 3mm or more and a length of the pyloric channel of 15mm or more, this typically indicates pyloric stenosis. It may also show a “target” sign and a lack of gastric emptying.
If an ultrasound doesn’t give a clear diagnosis, a substance known as barium might be used. It shows an elongated pylorus and delayed emptying of the stomach. It might also reveal signs like a “string” sign, a “double-track” sign, or a “beak” sign.
In rare cases, the upper endoscopy could be used. This method involves a small camera on a flexible tube to view the child’s digestive tract up close. It is used if the other tests are unclear or if the child has unusual symptoms.
A simple abdominal X-ray is not often used as it may miss some details. It may show a large amount of gas in the child’s stomach with none in the colon due to a blockage of the stomach. A “caterpillar” sign may also be present, which is a unique pattern in the stomach due to the enlarged pylorus.
Treatment Options for Pyloric Stenosis
Firstly, treatment usually starts by correcting the fluid levels in the body and balancing the electrolyte levels, vital for normal body functions. If the dehydration signs are not severe, a specific solution containing glucose, sodium chloride, and potassium chloride is administered. In case of moderate to severe dehydration, the body might require a higher concentration of saline solution. Bicarbonate levels should also be regularly checked and adjusted, as they can affect the breathing.
In severe situations where the child can’t eat or drink properly, the doctors may also consider using a nasogastric (NG) tube. This is a thin, flexible tube passed through the nose, down the throat, and into the stomach to provide nutrition.
Once the infant’s hydration levels are back to normal, the next course of treatment is usually surgery. The specific surgical procedure is called pyloromyotomy. During this procedure, a muscle at the lower part of the stomach (the pylorus) is split to the soft tissue layer underneath without injuring the inner lining of the stomach.
The operation can be performed using traditional open surgery or minimally invasive laparoscopic surgery, depending on the surgeon’s preference or the infant’s specific needs. Pyloromyotomy is a highly effective treatment for this condition and generally has a low risk of complications or side effects.
What else can Pyloric Stenosis be?
Midgut volvulus is a medical condition where the intestine twists abnormally. This condition can appear during the first month of a baby’s life and often causes symptoms like bile-stained vomit. To identify this, doctors may take an upper GI series, a type of x-ray that shows what’s happening in the upper gut. In this condition, the x-ray will usually show a “corkscrew” pattern in the intestine. An abdominal CT scan can also reveal that the positions of the superior mesenteric artery and the superior mesenteric vein, two important blood vessels in the abdomen, are irregular.
However, midgut volvulus is not the only possible cause of these kinds of symptoms. Other ailments that could explain them include:
- Stomach flu (gastroenteritis)
- Sudden kidney failure (acute renal failure)
- A severe body-wide infection (sepsis)
- An abnormal opening in the abdominal wall (hernia)
- Intense crying in a healthy baby (colic)
- Hard, irregular bowel movements (constipation)
- A dangerous condition that affects the bowel of premature babies (necrotizing enterocolitis)
- Physical injury (trauma)
- A severely inflated colon caused by disease (toxic megacolon)
- A condition that affects the large intestine and causes problems with passing stool (Hirschsprung disease)
- Painful twisting of the testicles (testicular torsion)
- Inflammation of the appendix (appendicitis)
- Urinary Tract Infection
What to expect with Pyloric Stenosis
When caught early, the outlook is very good. Surgery can completely cure the condition and it carries a very low risk of death.
Possible Complications When Diagnosed with Pyloric Stenosis
Not getting a diagnosis in time can cause serious dehydration and a sudden drop in blood pressure, known as hypovolemic shock.
Common Effects of a Delayed Diagnosis:
- Severe dehydration
- Hypovolemic shock, a sudden drop in blood pressure
Recovery from Pyloric Stenosis
After surgery, the only care needed is to continue giving fluids through a vein until the patient can tolerate feeding. Feeding can usually start 4 to 8 hours after the patient wakes up from anesthesia.
Up to 80% of patients may still experience some form of mild vomiting after surgery. If the vomiting continues 5 days after the surgery, doctors may carry out further diagnostic tests, for example, an upper GI series – an exam that checks the upper part of the gastrointestinal tract.
After the surgery, infants need to stay in the hospital for a while so that the medical staff can watch out for any surgical complications such as incomplete pyloromyotomy (an incomplete cut into the pylorus), mucosal perforation (holes in the mucosa, the lining of the stomach or intestines), and bleeding.
The infants can go home once they are well-hydrated and able to tolerate feedings well.
Preventing Pyloric Stenosis
Doctors and nurses should inform parents about the significant risk of passing on a condition called pyloric stenosis within families. This condition, which causes a blockage in the stomach, is nearly 200 times more likely to occur in identical twins and 20 times more likely among brothers and sisters. Thus, it’s critical for parents to keep an eye out for symptoms in their future children as soon as possible.
