Congenital Aganglionic Megacolon Flashcards
Definition
• Functional obstruction of the colon due to absence of ganglion cells in bowel wall
• Commonest site: rectosegmoid in 75%
. 10% of cases total —->ileostomy
Incidence
- 1 / 5000
* Male: Females = 4: 1 (positive family history may be present).
Clinical picture/Presentation
Neonatal (80%):
Delayed passage of meconium beyond 48 hours.
• May be acute obstruction
In older child:
Chronic constipation and abdominal distension.
• Large fecal mass felt in left lower abdomen with empty rectum
Clinical picture/
Complicated cases:
🌚 Enterocolitis:
- Infection with clostridia difficile, staph aureus and anaerobes
- Presented with bloody diarrhea & toxemia
🌚 Intermittent attacks of intestinal obstruction.
🌚 Failure to thrive due to protein losing enteropathy
Investigations
🌚🌝contrast enema
Barium enema:→ olderthen 1m
Gastrographin → younger then 1m
• Classic findings: an abrupt narrow transition zone between the normal dilated proximal colon and a smaller caliber obstructed distal aganglionic segment
🌚🌝 Rectal suction biopsy (from narrow segment)
• The gold standard for diagnosing Hirschsprung disease
• Reveals absent ganglia + hyper trophid neve endings
TX
pull-through procedure: surgical resection of aganglionic intestinal segment and anastomosis of remaining intestine to anus Either in newborn period or staged if extensive aganglionosis
Prognosis
Most have normal/ near-normal anorectal function Complications: fecal incontinence and constipation, postoperative enterocolitis (medical emergency if progresses to sepsis)