What is the most appropriate management for a 5-month-old infant with dehydration, non-bilious vomiting, and an olive-shaped mass in the epigastric region, suggestive of pyloric stenosis?

Management of Hypertrophic Pyloric Stenosis in a 5-Month-Old Infant

Pyloromyotomy is the definitive treatment for this infant with classic hypertrophic pyloric stenosis (HPS), and laparoscopic pyloromyotomy is the preferred surgical approach when expertise is available. 1, 2

Clinical Diagnosis

The clinical presentation is pathognomonic for HPS:

• Non-bilious vomiting in an infant aged 5 months (though typical onset is 2-12 weeks) 3
• Palpable olive-shaped mass in the epigastric region measuring 2 × 2 cm 3
• Dehydration from persistent vomiting 1

The American College of Radiology recommends ultrasound as the most appropriate initial imaging when HPS is suspected based on forceful, nonbilious vomiting and a palpable "olive" in the right upper quadrant 3. However, when the olive is clearly palpable on physical examination, the diagnosis is clinical and imaging may not be necessary before proceeding to surgical management.

Preoperative Management

Before surgery, correct the metabolic derangements:

• Restore hydration status with intravenous fluids 1, 4
• Correct electrolyte imbalances (typically hypochloremic, hypokalemic metabolic alkalosis) 5
• Optimize acid-base status 5

All patients should be medically optimized before proceeding to surgery 5.

Definitive Surgical Treatment

Pyloromyotomy (Option A) is the correct answer and gold-standard treatment for HPS 1, 6, 2:

Laparoscopic vs Open Approach

• Laparoscopic pyloromyotomy is superior to open pyloromyotomy based on the highest quality randomized controlled trial evidence 1
• Laparoscopic approach achieves full enteral feeding faster (18.5 hours vs 23.9 hours, p=0.002) 1
• Shorter postoperative length of stay (33.6 hours vs 43.8 hours, p=0.027) 1
• Lower overall complications (1.4% vs 2.9%) and surgical site complications (1.1% vs 2.1%) 2
• Superior cosmetic results 6
• Similar safety profile with no difference in re-operation rates 2
• Laparoscopic pyloromyotomy utilization has increased from 59% in 2013 to 65.5% in 2015 2

Why Other Options Are Incorrect

Balloon dilatation (Option B) is not a standard treatment for HPS:

• No evidence supports balloon dilatation for infantile pyloric stenosis
• This modality is used for other conditions like achalasia or strictures, not HPS 7

Gastrojejunostomy (Option C) is inappropriate for HPS:

• Gastrojejunostomy is reserved for refractory gastroparesis or when enteral nutrition is required for prolonged periods 7
• This is a bypass procedure, not a treatment for the hypertrophied pyloric muscle 7
• Pyloromyotomy directly addresses the pathology by dividing the hypertrophied pyloric muscle

Medical Management Alternative

While intravenous atropine therapy has been studied with 87% success rates, it requires:

• Median 7 days of IV atropine followed by 44 days of oral atropine 4
• Median hospital stay of 13 days 4
• Acceptance of prolonged treatment duration 4

Surgery remains superior due to shorter hospital stay, definitive cure, and avoidance of prolonged medical therapy 1, 4, 2.

Common Pitfalls to Avoid

• Do not proceed to surgery without correcting dehydration and electrolyte abnormalities 5
• Do not delay diagnosis when classic clinical findings are present—the palpable olive is diagnostic 3
• Ensure laparoscopic expertise is available at the surgical center, as outcomes depend on surgical experience 1, 6