Hirschsprung's disease, true is:
|A||Normal manometry excludes the disease|
|B||Giant ganglion cells are seen|
|C||Suction biopsy is contraindicated in neonates|
|D||Lower segment is dilated|
a. The initial diagnostic step in a newborn with radiographic evidence of a distal bowel obstruction is a barium enema.
b. Before this study, rectal examination and enemas are avoided so that they do not interfere with the identification of a transition zone.
c. In a normal barium enema study, the rectum is wider than the sigmoid colon.
d. In patients with Hirschsprung's disease, spasm of the distal rectum usually results in a smaller caliber when compared with the more proximal sigmoid colon.
e. Identification of a transition zone may be quite helpful
f. Failure to completely evacuate the instilled contrast material after 24 hours would also be consistent with Hirschsprung's disease and may provide additional diagnostic yield.
g. An important goal of this study is to exclude other causes of constipation in the newborn, such as meconium plug, small left colon syndrome, and atresia.
h. Anorectal manometry may also suggest the diagnosis of Hirschsprung's disease.
i. The classic finding is failure of the internal sphincter to relax when the rectum is distended with a balloon.
j. A rectal biopsy is the gold standard for the diagnosis of Hirschsprung's disease.
k. In the newborn period, this is done at the bedside with minimal morbidity using a special suction rectal biopsy instrument.It is important to obtain the sample at least 2 cm above the dentate line to avoid sampling the normal transition from ganglionated bowel to the paucity or absence of ganglia in the region of the internal sphincter.
l. In older children, because the rectal mucosa is thicker, a full-thickness biopsy is obtained under general anesthesia.
m. Absent ganglia, hypertrophied nerve trunks, and robust immunostaining for acetylcholinesterase are the pathologic criteria to make the diagnosis.