Prepared By MAGED ZAKARIA NICU RESIDENT Hirschsprung Disease
In 1886, Harold Hirschsprung first described Hirschsprung disease (congenital aganglionicmegacolon)as a cause of constipation in early infancy. Background
Early recognition and surgical correction of Hirschsprung disease protects affected infants from enterocolitis and debilitating constipation. Background
HD results from the absence of enteric neurons within the myenteric and submucosal plexus of the rectum and/or colon. Enteric neurons are derived from the neural crest and migrate caudally with the vagal nerve fibers along the intestine. Pathophysiology
These ganglion cells arrive in the proximal colon by 8 weeks' gestation and in the rectum by 12 weeks' gestation. Arrest in migration leads to an aganglionic segment. An obstruction occurs at the point of aganglionosis as peristalsis cannot progress beyond this point. Pathophysiology
1 in 5000 live birth (in the US) Male : Female Ratio 4 : 1 +ve Family History in 30% of cases Frequency
The overall mortality of Hirschsprungenterocolitis is 25 – 30 % (almost accounts for all of the mortality from the disease). Mortality
Abdominal distention. Delayed passage of meconium (> 48 hours of life). Repeated vomiting. Tympanitic abdominal distention. Intestinal obstruction. Acute Enterocolitis. Meconium plug Syndrome. Nearly one half of infants with delayed first passage of meconium have Hirschsprung disease. Presentation in the Neonatal Period
Down syndrome (5–15%) Waardenburg syndrome Congenital deafness Malrotation, Gastric diverticulum or Intestinal atresia. Urogenital abnormalities. Cardiovascular abnormalities. Associated Disorders
CBC with differential count: if enterocolitis is suspected. Plain abdominal radiography. Unprepared contrast enema (If perforation and enterocolitis are not suspected): A transition zone between a narrowed aganglionic segment and a dilated and normally innervated segment. Non-distensible rectum. A transition zone may not be apparent in neonates, because of insufficient time to develop colonic dilation, or in infants who have undergone rectal washouts, examinations, or enemas. If enterocolitis is present, the colon will appear dilated and there may be pneumotosis. Investigations
Plain Abdominal X-ray Abdominal radiograph demonstrating small bowel obstruction and megacolon in infant with Hirschsprung Disease
Contrast Enema Contrast enema demonstrating transition zone. The transition zone shows the transition from dilated, normally innervated bowel to normal caliber, non-innervated bowel.
Contrast Enema Lateral view from a contrast enema examination showing the reduced diameter of the rectum and sigmoid colon in HD
Contrast Enema Contrast enema showing reduced caliber of the rectum, followed by a transition zone to an enlarged-caliber sigmoid colon
Plain Abdominal X-ray Frontal abdominal radiograph showing marked dilatation of the bowel with no gas in the rectum.
In the sitting position, air-fluid levels in the large bowel are seen Plain Abdominal X-ray
Helpful In older children who present with chronic constipation and an atypical history.
Children with HD fail to demonstrate reflex relaxation of the internal anal sphincter in response to inflation of a rectal balloon.
The definitive diagnosis of Hirschsprung disease rests on histological review of rectal tissue by rectal suction biopsy or transanal wedge resection. Investigations
If presented with intestinal obstruction, initial therapy should include: Intravenous hydration Withholding of enteral intake Gastric decompression through a NG tube Request surgical consultation. Intestinal decompression through either digital rectal examination or normal saline rectal irrigations 3-4 times daily. Broad-spectrum antibiotics with enterocolitis. Medical Care
The Operative Options: Definitive Repair as soon as the diagnosis is established Temporary colostomy until the infant is 6–12 mo old to perform definitive repair. Surgical Care
The 1st successful surgical procedure, described by Swenson, was to excise the aganglionic segment and anastomose the normal proximal bowel to the rectum 1–2 cm above the dentate line. The operation is technically difficult. Surgical Care
Duhamel described a procedure to create a neorectum, bringing down normally innervated bowel behind the aganglionic rectum. The neorectum created in this procedure has an anterior aganglionic half with normal sensation and a posterior ganglionic half with normal propulsion. Surgical Care
The endorectal pull-through procedure described by Boley involves stripping the mucosa from the aganglionic rectum and bringing normally innervated colon through the residual muscular cuff, thus bypassing the abnormal bowel from within. Advances in techniques have led to successful laparoscopic endorectal pull-through procedures, which are the treatment of choice. Surgical Care