Hirschsprung Disease Flashcards
What is the most common cause of lower intestinal obstruction in the neonate?
Hirschsprung disease
What is the etiology of Hirschsprung disease?
It is due to the absence of enteric ganglionic neurons (aganglionosis) that begins at the anus and extends proximally for a varying distance. It arises in utero when neural crest cells fail to migrate from the craniocaudal region to the distal intestine. The aganglionic segments remain continuously contracted, resulting in obstructive symptoms with proximal dilation and hypertrophy.
What five syndromes have an increased incidence of Hirschsprung disease?
Down syndrome, Bardet-Biedl syndrome, Smith-Lemli-Opitz syndrome, Mowat-Wilson syndrome, and Waardenburg syndrome.
What is Mowat-Wilson Syndrome?
It is a syndrome associated with Hirschsprung disease, dysmorphic facial features (square face, hypertelorism, broad nasal bridge, prominent nasal tip, posteriorly rotated ears, and a full, sometimes everted, lower lip), heart defects, GU anomalies, and intellectual disability.
A term infant is 48 hours old and has not passed meconium. Is it necessary at this point to evaluate for Hirschsprung’s?
Yes. 90% of normal, FT infants pass meconium within 24 hours, and 99% within 48 hours. In children with Hirschsprung disease, 94% fail to pass meconium within the first 24 hours of life. Therefore, if they haven’t passed meconium by 48 hours of life, evaluation is warranted.
How does enterocolitis present in infants with Hirschsprung’s?
It typically presents during the 2nd to 4th weeks of life and in characterized by fever with explosive, foul-smelling stools. Bloody diarrhea and abdominal distention are common. X-ray shows dilated loops of bowel with air-fluid levels.
What is the gold standard procedure used to diagnose Hirschsprung’s?
Rectal biopsy; most commonly suction rectal biopsy.
A biopsy shows histologic absence of what structure in a patient with Hirschsprung disease?
Histologically, the diagnosis is based on the absence of any ganglion cells detected in a biopsy containing adequate submucosa.
What abnormality has a presentation similar to that of Hirschsprung disease?
Meconium plugs
What four syndromes have an increased incidence of meconium plugs?
Hirschsprung disease, hypothyroidism, cystic fibrosis, and small left colon syndrome.
What is the recommended treatment of Hirschsprung disease?
Surgical resection of the aganglionic bowel with reanastimosis of the normal bowel to the normal anal canal.
What is the recommended management of entercolitis related to Hirschsprung disease?
Treat with IV fluid, broad-spectrum antibiotics, NG decompression, and warm normal saline rectal washouts to help with colonic decompression. Once the patient is stable, perform a proximal colostomy.
What two disorders are considered pseudo-Hirschsprung disease?
Hypoganglionosis and intestinal neuronal dysplasia
What is hypoganglionosis?
It is a type of pseudo-Hirschsprung disease that can be congenital or acquired. It occurs when the number of myenteric neurons is decreased. The congenital form is likely 2/2 abnormal neural crest cell migration, whereas the acquired form results from toxic or autoimmune effects on neurons.
What is intestinal neuronal dysplasia?
It is a very rare type of pseudo-Hirschsprung disease that is characterized by hyperganglionosis and giant ganglia on full-thickness rectal biopsy.
