Neonatal Disease Flashcards
What is Hirchsprung disease?
Hirchsprung disease is the most common cause of lower gastrointestinal obstruction in neonates. Infants with this disease have chronic constipation, fecal impaction, and overflow diarrhea.
Incidence: The disease occurs in 1 out of 5000 children, with a male-to-female ratio of 4:1.
Causes: The condition is caused by congenital absence of some or all of the normal bowel parasympathetic ganglion cells, beginning at the anus and extending variable lengths proximally; 75% of cases are limited to the immediate rectosigmoid area. The aganglionic bowel segment contracts, but there is no reciprocal relaxation; therefore feces cannot be moved onward through the bowel. Unless diagnosed and treated quickly, the colonic obstruction caused by Hirschsprung may result in fecal stagnation, bacterial overgrowth with toxin production, enterocolitis, overflow diarrhea, hypovolemic shock, and infant death.
Symptoms: Refractory constipation occurring in infancy or early childhood is characteristic. About 15% of cases are diagnosed in the first month of life, 64% by the third month, and 80% by age 1 year. Only 8% remain undiagnosed by 3 years of age.
Diagnosis: Barium contrast enema is usually used for diagnosis, but for mild cases when the enema result is negative, rectal biopsy is the diagnostic standard. Anorectal manometry or suction biopsy of rectal tissue are the most precise tests used to diagnose Hirschsprung disease.
Treatment: Surgical excision of the affected segment of bowel and reanastomosis of healthy bowel are standard, and many surgical techniques have been used. The optimal surgical technique for treating the disease is uncertain.
