Hirschsprung's Disease in Neonates: Key Characteristics
Enterocolitis is the leading cause of death in neonatal Hirschsprung's disease. This life-threatening complication can occur both before and after surgical correction of the aganglionic segment and represents the most significant mortality risk for affected infants 1.
Pathophysiology and Diagnosis
- Hirschsprung's disease (HSCR) is characterized by the absence of ganglion cells in both the myenteric (Auerbach's) and submucosal (Meissner's) plexuses of the intestine, resulting from failure in enteric nervous system development 2, 3
- The condition affects approximately 1 in 5,000 live births and typically presents in the neonatal period 2
- Common presenting symptoms include:
- Delayed passage of meconium (beyond 24 hours after birth)
- Abdominal distension
- Vomiting 2
Diagnostic Approach
- While contrast enema may show a transition zone suggestive of HSCR, it is not considered confirmatory for diagnosis 2
- Definitive diagnosis requires rectal biopsy demonstrating absence of ganglion cells in the affected bowel segments 2
- Three-dimensional imaging techniques have recently shown that the aganglionic segments completely lack enteric nervous system structures, confirming the histopathological hallmark of the disease 4
Gender Distribution and Associated Conditions
- HSCR predominantly affects males, not females, with a male-to-female ratio favoring males 2
- The condition is frequently associated with other syndromes and chromosomal abnormalities:
- Trisomy 21 (Down syndrome)
- Mowat-Wilson syndrome
- Congenital central hypoventilation syndrome
- Shah-Waardenburg syndrome
- Cartilage-hair hypoplasia 2
- Genetic factors play a significant role, with mutations in the RET proto-oncogene and EDNRB being most commonly implicated 2
Hirschsprung-Associated Enterocolitis (HAEC)
- HAEC is the most serious and life-threatening complication of Hirschsprung's disease 1, 3
- It can present either before or after surgical correction of the aganglionic segment 5
- The pathogenesis involves multiple factors:
- Intestinal dysmotility
- Microbial dysbiosis
- Impaired mucosal defense
- Compromised intestinal barrier function 5
- Clinical presentation typically includes fever, diarrhea, and abdominal distension 3
- Early recognition and prompt treatment are essential to prevent mortality 3
Histopathological Features
- The defining histopathological characteristic is the complete absence of ganglion cells in the affected bowel segments 2, 3
- The aganglionic segments show absent nerve trunks, not just absent ganglion cells 4
- Recent three-dimensional imaging studies have revealed significant variations in enteric neuron density at the proximal margins of resected bowel in HSCR patients, which may contribute to post-surgical complications 4
Management
- Treatment primarily involves surgical removal of the aganglionic bowel segment and reconstruction of the intestinal tract 2
- Several surgical approaches exist, including Swenson, Soave, and Duhamel procedures, which may be performed with laparoscopic assistance 2
- Post-operative complications include persistent obstructive symptoms, enterocolitis, and soiling 2
- Vigilant monitoring for signs of enterocolitis is essential both before and after surgical correction 5, 1
In summary, the most accurate statement regarding neonatal Hirschsprung's disease is that enterocolitis is the leading cause of death. The disease is characterized by absent ganglion cells in the affected bowel segments, predominantly affects males rather than females, and is definitively diagnosed by rectal biopsy rather than barium enema.