Hirschprung disease by dr manzoor

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  • Developmental Disorder HirscHsprung Disease Congenital aganglionic Megacolon By Dr Mohammad Manzoor Mashwani
  • Hirschsprung disease Congenital Aganglionic Megacolon Hirschsprung disease is a developmental disorder of the enteric nervous system and involves an enlargement of the colon, caused by bowel obstruction resulting from an aganglionic section of bowel that starts at the anus & progresses upwards. Harald Hirschsprung, Danish Physician 1886
  • Pathogenesis Two pathogenetic mechanisms have been proposed for Hirschsprung's disease (1) failure of migration of neuroblasts to the distal intestine ( rectum). (2) alteration of the colonic microenvironment Genetic, vascular, and infectious factors are invoked to explain these alterations . Normal migration may occur with a failure of neuroblasts to survive, proliferate or differentiate in the distal aganglionic segment.
  • Epidemiology Rate of occurrence 1 case per 5000 live births. Race - no racial predilection. Sex M: F = 4:1. Long S.D F Age: Full term baby, uncommon in premature baby, Can occur in adult life.
  • Hirschprungs Disease, diagrammatic representation of the pathologic changes
  • Morphology
  • Gross specimen of Hirschprungs Disease. The proximally dilated segment of bowel has been resected.
  • Depending on the extent and location of the aganglionic segment, several forms of the disease have been recognized: 1 Classic form. The aganglionic segment begins in the distal colorectum and extends for a considerable distance in the adjoining proximal dilated bowel. 2 Short-segment form. The aganglionic segment involves the rectum and rectosigmoid for a distance of only a few centimeters. 3 Ultra-short segment form. In this variant, the aganglionic segment is so short that the diagnosis can be missed if the biopsy is taken too high. 4 Long-segment form (total colonic aganglionosis). Here the abnormality is more extensive, involving most or all of the large bowel, and occasionally extending even to the small bowel. These patients present with symptoms of intestinal obstruction without megacolon. 5 Zonal colonic aganglionosis. Only a short segment of bowel is involved. In contrast to all other forms, ganglion cells are present not only above but also below the aganglionic segment.
  • Morphology Microscopically, the hallmark of the disease is the absence of ganglion cells (aganglionosis) in both plexuses of a segment of bowel.
  • Colonic mucosa stained for acetylcholinesterase from a patient with Hirschsprung disease. There is a marked increase in the number of nerve fibers in the lamina propria.
  • Clinical features 1) Delayed passage of meconium 2) Abdominal distension 3) Constipation
  • Diagnosis Suspect Hirschsprung's in a baby who has not passed meconium within 48 hours of delivery. Recall that 90% of babies pass their first meconium within 24 hours, and the next 9% within 48 hours. Definitive diagnosis is made by biopsy of the distally narrowed segment. Abdominal x-ray ( Plain) x-ray) Barium Enema (Contrast Anorectal manometry 1. Full thickness biopsy 2. Suction biopsy
  • Treatment Surgical removal (resection) of the abnormal section of the colon, followed by reanastomo sis. Initial therapy should include intravenous hydration, withholding of enteral intake, and intestinal and gastric decompression. Decompression can be accomplished through placement of a nasogastric tube and either digital rectal examination or normal saline rectal irrigations 3-4 times daily. Administer broad-spectrum antibiotics to patients with enterocolitis.
  • Your practice of medicine will be as good as your understanding of pathology Sir William Osler.