Hirschsprung Disease

Snapshot

• A 2-day-old neonate is noted in the well-baby nursery to have some abdominal distention.  He had one episode of bilious vomiting. He is feeding well and does not seem altered. However, his mom is concerned that he has not passed any stool yet. Abdominal radiography shows distended loops of bowel. A barium enema shows a dilated colon with a funnel-shaped transition zone.  Pediatric surgery is consulted for biopsy and surgical correction.

Introduction

• Congenital megacolon
  • functional (vs mechanical) intestinal obstruction
• Pathogenesis 
  • absence of ganglion cells/enteric nervous plexus in intestine
  • lack of nerves causes constant contraction 
  • failure of neural crest cell migration 
  • 99% localized in rectum
• Genetics
  • associated with mutations in RET gene
• Associated conditions
  • risk ↑ with Down syndrome
  • risk ↑ with Chagas disease
• acquired disease as a result of amastigote destruction of ganglion cells

Presentation

• Symptoms
  • bilious vomiting
  • failure to pass meconium in first 48 hours of life
  • chronic constipation
  • large bowel obstruction
• Physical exam
  • abdominal distention
  • extremely tight anal sphincter
• no stool in rectal vault

Evaluation

• Gold standard diagnosis
  • rectal suction biopsy
    • lack of ganglionic cells in submucosa 
• Imaging
  • abdominal radiography
    • distended bowel loops
• lack of air in rectum

Differential Diagnosis

• Imperforate anus
• Functional constipation
• Intussusception 
• Duodenal atresia 
• Meconium ileus 

Treatment

• Supportive care
• Surgical resection

Prognosis, Prevention, and Complications

• Prognosis
  • very good
  • overall mortality < 1%
  • normal quality of life in most patients
• Complications
  • ↑ risk of enterocolitis
  • rupture