Maryangela (AGMD)

Hirschsprung Disease (Congenital Aganglionic Megacolon) is a congenital disorder of the intestine characterized by the absence of ganglion cells in the submucosal (Meissner) and myenteric (Auerbach) plexuses, most commonly affecting the distal colon and rectum. This results in a functional intestinal obstruction due to failure of relaxation of the affected bowel segment. Etiology & Pathophysiology- Caused by failure of neural crest cell migration during embryogenesis. The aganglionic segment remains tonically contracted, while the proximal bowel becomes dilated (megacolon). Can be sporadic or genetic (associated with mutations in the RET proto-oncogene). Associated conditions: Down syndrome, congenital heart disease, MEN type 2. Epidemiology Incidence: ~1 in 5,000 live births-Male predominance (≈4:1) Majority present in the neonatal period Clinical Features Neonates -Failure to pass meconium within 24–48 hours ,Abdominal distension ,Bilious vomiting Explosive stool on digital rectal examination Infants & Children -Chronic constipation since birth Poor feeding, failure to thrive Recurrent enterocolitis (life-threatening) Adults (rare) -Long-standing severe constipation Abdominal distension Diagnosis -Contrast enema: Narrow distal segment with proximal dilatation (transition zone) Anorectal manometry: Absence of recto-anal inhibitory reflex (RAIR) Gold standard: Rectal biopsy showing: Absence of ganglion cells Increased acetylcholinesterase -positive. nerve fibers Management Definitive treatment is surgical Resection of aganglionic segment with pull-through procedures: Swenson , Duhame , Soave Temporary stoma may be required in sick neonates Complications Hirschsprung-associated enterocolitis (HAEC) Bowel perforation Post-operative constipation or incontinence Prognosis -Excellent with early diagnosis and appropriate surgery Long-term bowel function usually satisfactory #MedTwitter #MedEd #MedX