Pyloric stenosis

• Pyloric stenosis is a condition where the passage between the stomach and the small intestine (the pylorus) becomes narrowed due to hypertrophy and hyperplasia of the pyloric sphincter muscle.
• This leads to obstruction and is most commonly seen in infants.

• Most commonly affects infants between 2-8 weeks old.
• More prevalent in males than females, with a 4:1 ratio.
• There is a genetic predisposition; it can run in families.

• The exact cause is unknown, but it is thought to be multifactorial, involving genetic, environmental, and hormonal factors.
• Hypertrophy and hyperplasia of the pyloric muscle lead to narrowing of the pyloric canal.
• This obstruction results in forceful vomiting, dehydration, and electrolyte imbalances.

• Progressive, projectile vomiting that may be blood-tinged.
• The vomiting typically occurs shortly after feeding, and despite vomiting, infants are usually hungry.
• Palpable ‘olive’ mass in the right upper quadrant of the abdomen.
• Visible gastric peristalsis in severe cases.

• History and physical examination are paramount. A thorough feeding history and pattern of vomiting are essential.
• Ultrasound is the diagnostic modality of choice, showing elongation and thickening of the pylorus.
• Blood tests may show hypochloremic metabolic alkalosis due to loss of gastric acid from vomiting.

• Initial treatment focuses on correcting dehydration and electrolyte imbalances with IV fluids.
• Surgical intervention (pyloromyotomy) is the definitive treatment where the outer layer of the pyloric muscle is cut to relieve the obstruction.
• Postoperative care includes gradual reintroduction of feeding and monitoring for complications such as infection or hernia.

• If left untreated, pyloric stenosis can lead to severe dehydration, weight loss, and electrolyte imbalances.
• Postoperative complications include wound infections, incomplete pyloromyotomy, or mucosal perforation.

• With appropriate and timely treatment, the prognosis is excellent.
• Most infants have prompt relief of symptoms post-pyloromyotomy and can resume normal feeding.

There are no known preventive measures, given the unclear aetiology.

• Pyloric stenosis should be suspected in any young infant with projectile vomiting.
• Prompt recognition and treatment are essential to prevent complications.
• Multidisciplinary management, involving paediatricians, surgeons, and nutritionists, is often required for optimal patient care.