Hirschsprung Disease: Short Notes

Disease caused by absence of ganglions in the myenteric (Auerbach) and submucosal (Meissner) plexus causing functional intestinal obstruction.

Long-segment Hirschsprung: Aganglionic bowel proximal to midtransverse colon 

Embryology and Etiology

Ganglion cells originate from the neural crest tissues by 13 weeks postconception from proximal to distal GIT.

2 theories:

• Failure of migration of neural crest tissues.
• Failure of migrated ganglionic cells to mature and proliferate

 Mutation of RET proto-oncogenes

Associated Syndromes

Down syndrome
Neurocristopathy syndromes (ie. Waardenberg-Shah syndrome)
Malrotation
Congenital heart disease
Urinary tract anomalies
Central nervous system anomalies
Congenital central hypoventilation syndrome (Ondine curse)

Clinical Features

Neonates:

• Delayed passage of meconium after 24 hours
• Abdominal distension
• Bilious vomiting
• Feed intolerance

- Chronic constipation
- Diarrhea, fever, abdominal distension (Hirschprung-associated enterocolitis [HAED])


Investigations

Radiographic
- Abdominal X-ray
- Barium enema

• Transition zone between normal and aganglionic bowel
• Reversed recto-sigmoid index (< 1.0)

Anorectal Manometry

• Recto-anal inhibitory reflex (RAIR). Reflex that causes the internal anal spinchter to relax when the rectum is distended.
• Balloon inserted into the rectum and inflated. If reflex present detected by sensor.
• Test more useful with older children.

Rectal biopsy

• Absence of ganglionic cell
• Hypertrophied nerve trunk
• Acetylcholinesterase staining
• Absence of calcitonin on immunochemical testing with calretinin

Management

Resuscitation

• Fluids
• Nasogastric tube
• Antibiotics

Operative

May be done through laparotomy or more popular, pull-through surgery via the anus.

• Swenson (end-to-end anastamosis of the ganglionic segment with the internal anal sphincter. Rectum is excised)
• Soave (As Swenson but rectum is preserved becoming the outer 'cuff' of the pulled ganglinic segment)
• Duhamel (The ganglinic segment is joined to the rectum in a end-to-side anastamosis)

Colostomy to consider:

• Enterocolitis
• Perforated bowel
• Very dilated proximal bowel

Surgery for Long-segment Hirschsprung:

• Ileostomy
• Small bowel pull-through to anastamose with the anal sphincter
• Side-to-side anastamosis between small bowel and large bowel (to preserve absorptive roles). Several techniques: Martin and Kimura

 Post-op Care

• Anal calibration 4 to 6 weeks
• Buttock care with barrier cream to prevent perineal wound breakdown

  
 References:

1. Coran, Arnold G., et al., Pediatric Surgery, 7th Ed., Elsevier

Both pictures from http://radiopaedia.org/cases/hirschsprung-disease