Hirschsprung Disease

• • Distal colon aganglionosis resulting in dysfunctional myenteric plexus

  • Associated cardiac defects in 2-5%

  • Trisomy 21 in 5-15%

  • Occasionally preceded by neonatal appendicitis or meconium plug syndrome

  • 50% of cases diagnosed in neonates, almost 50% of cases diagnosed in children younger than 2, and rarely in older children or adults

Epidemiology

• • 1/5000 births

  • 4:1 male:female ratio

Symptoms and Signs

• • Failure to pass meconium in first 24-48 hours of life

  • Feeding intolerance

  • Abdominal distention

  • Bilious emesis

  • Chronic constipation

  • Fever (if entercolitis complicating)

  • Rectal spasm

  • Abdominal pain (if complicated by enterocolitis)

  • Diarrhea, occasionally bloody (if enterocolitis present)

Imaging Findings

• • Abdominal x-ray

  • -Shows intestinal obstruction (occasionally distal transition point visualized)

    -Pneumatosis intestinalis if enterocolitis present

  • Contrast enema shows transition zone distally (but may not be present in neonates)

  • Anorectal manometry shows failure of relaxation to balloon distention

• • Causes of low intestinal obstruction in neonates include:

  • -Rectal or colonic atresia

    -Meconium plug syndrome

    -Meconium ileus

    -Hypermagnesemia

    -Hypocalcemia

    -Hypokalemia

    -Hypothyroidism

• • History and physical exam

  • Abdominal x-ray

  • Contrast enema

  • Suction rectal biopsy (85-90% sensitive)

Surgery

• • Diverting colostomy for neonates with enterocolitis and Hirschsprung disease (colostomy must contain ganglia)

  • Duhamel, Soave, or Swenson procedure at age 9-12 months or once proximal dilation has subsided after diverting colostomy

Complications

• • Anastomotic leak or stricture

  • Abscess

  • Obstruction

  • Enterocolitis (10-30%)

Prognosis

• • 80-90% maintaining good bowel function

References