PEDS SURG Flashcards
Omphalocele is characterized by:
Omphalocele is characterized by a large abdominal wall defect (>4 cm) covered by an amniotic membrane that contains midgut and other abdominal organs including the liver and often the spleen and gonad. Unusual forms of omphalocele are the cephalic fold defect or pentalogy of Cantrell and the caudal fold defect or cloacal exstrophy.
Neuronal Intestinal Dysplasia Type A, Type B
Two distinct morphologic and clinical subtypes (type A and B) of neuronal intestinal dysplasia (NID) exist. They have a common clinical presentation consisting of chronic constipation and megacolon. Type A (less than 5% of all cases) is congenital aplasia or hypoplasia of myenteric sympathetic innervation with increased acetylcholinesterase activity in the lamina propria, muscularis 503mucosa, and circular muscle. Ganglion cells are present. This disease appears to be confined to the colon and causes a functional bowel obstruction with enterocolitis in the neonatal period. The colon is rigid and may have spastic segmental contractions. Ulcers, erosions, and absent peristalsis may be seen on contrast studies. A fulminant course with severe enterocolitis may necessitate early colostomy, but extensive colon resection is to be avoided. Type B is characterized by dysplasia of the parasympathetic submucosal plexus, hyperganglionosis, giant ganglia, and ectopic ganglion cells in the lamina propria with elevated acetylcholinesterase levels in similar areas of the bowel wall. Symptoms presenting around the sixth month of life may be indistinguishable from or associated with Hirschsprung’s disease. This dysplastic process may also be associated with neurofibromatosis, the multiple endocrine neoplasia type 2B (MEN2B) syndrome, anorectal malformations, and chronic intestinal pseudo-obstruction. Operation is rarely required. The nervous system of the bowel may mature over time in children with this disorder. Prokinetic agents (eg, cisapride), colon irrigation, and bowel cathartics may relieve symptoms until a normal histology and clinical improvement occur. If the problem persists beyond age 4, a more aggressive surgical approach may be required but this is rarely observed.
