HIRSCHSPRUNG’S DISEASE

(CONGENITAL AGANGLIONIC MEGACOLON)

DR. ELFADIL EISA IDRIS SULIMAN Associate professor of Pediatrics and child health

Is a developmental disorder of the enteric nervous system characterized by the absence of ganglion cells in the mucosa and mesenteric plexus.
It is the most common cause of intestinal obstruction in neonate.
Males more affected than females 4-1.
There is an increase familial incidence.
May be associated with other congenital defects e.g. Urogenital, cardiovascular, microcephaly, cleft palate, hydrocephalus and may be associated with Down syndrome, nephroplastoma ..etc.

Pathology

Absence of ganglion cells in the bowel wall extending proximally from the anus for a variable distance. This leads to inadequate relaxation, decreased motility and bowel hypertrophy in the affected bowel segment and of the internal anal sphincter.
Hirschsprungs disease can lead to intestinal obstruction.
The aganglionic segment is limited to the rectosigmoid (the most common site of agangliosis) in 80% of patient.
Approximately 10 - 15% of patients have long segment disease, and the disease extends proximal to the sigmoid colon.

In newborns:

Delayed passage of meconium > 48 hours after birth in mature infants. It is rare in premature infants.
Bilious vomiting.
Abdominal distention relieved by digital rectal examination.

Older children:

Swollen, distended abdomen.

img-4.jpeg|233x269 img-5.jpeg|198x272 img-6.jpeg|123x255 img-7.jpeg|118x246

Failure to pass stool lead to dilation of the proximal bowel and abdominal distention, so intraluminal pressure increase resulting in decrease blood flow and deterioration of the mucosal barrier.
Stasis leads to proliferation of bacteria which can lead to enterocolitis (clostridium difficile, staph aureus and anaerobes) with associated diarrhea, sepsis & sings of bowel obstruction.
In older children the abdomen is distended with a large fecal mass palpable in the left lower abdomen.
Rectal examination: Demonstrates empty rectum and when the finger is removed, there may be an explosive discharge of foul - smelling feces and gas.
Urinary retention with enlarged bladder and hydronephrosis can occur secondary to urinary obstruction.

Clinical picture.
FH.
Erect abdomen X-ray.
Barium enema: Shows a transitional zone where a market change in caliber occurs, with the dilated normal colon above and the narrowed aganglionic below (should not be done in patient suspected of having enterocolitis → perforation).

img-8.jpeg|177x234 img-9.jpeg|192x245

The transition zone is in the mid-descending colon.

Anorectal manometry: It shows an absence of normal relaxation of the internal sphincter, with a reduction in the intraluminal pressure in the anal canal when the rectum is distended with a balloon.
Rectal biopsy (gold standard for diagnosis):
- a) Suction rectal biopsy: Reduced mucosa and submucosa ganglion cells. It can be easily performance at the bedside.
- b) Full thickness rectal biopsy: The definitive diagnosis is confirmed by full-thickness rectal biopsy, demonstrates absence of ganglionic cells.
- The diagnostic yield of the full-thickness rectal biopsy is significantly better than suction biopsy.

Absent ganglion. Acetylcholinesterase staining shows hypertrophied nerve trunks, throughout the lamina propria and muscularis propria layers of the bowel wall.

NPO, NGT and IV fluid.
Correction of electrolytes.
Antibiotics before the operation.
Removal of the part of the colon that lacking nerve (aganglionic colon) and connected the healthy bowel to the rectum (pull-through operation).