quiz constipated patient

[Ahmed Nabil]

A two-year old boy has a history of chronic constipation. He passed meconium within 24 hours of life. However, he has required chronic laxatives and enemas to allow evacuation of stool. A contrast enema shows no evidence of a transition zone. Anal manometry shows failure of internal anal sphincter relaxation after rectal distention. A full thickness rectal biopsy two cm proximal to the dentate line shows no ganglion cells with increased acetylcholinesterase activity while a biopsy 4.5 cm proximal to the dentate line shows ganglion cells. The child has a transient response to a botulinum toxin injection.

The next best step in management of this constipated patient is

A serial anal dilations.

B internal sphincter myectomy.

C endorectal pull through

D cecostomy for antegrade enemas

E initiate biofeedback therapy

[Admin]

b

correct

Ultrashort segment Hirschsprung disease (UHD) is characterized by chronic constipation without classic findings of a transition zone on contrast enema. Some authors suggest that the diagnosis may be made on the basis of the clinical history and the absence of anal relaxation with rectal distention on rectal manometry with the presence of ganglion cells on rectal biopsy. Others might consider this to be internal anal spincter achalasia. In the scenario presented in the question, ganglion cells are absent for a very short segment with the presence of increased acetylcholinesterase (AChE) activity, thereby confirming the diagnosis of Hirschsprung disease. Criteria described by Meier-Ruge would indicate that UHD may extend up to six cm from the dentate line. These authors feel that confirmation of the diagnosis requires a full thickness biopsy, as ganglion cells may be absent in the submucosa of the very distal rectal and anal segment. The absence of ganglion cells and the increase of AChE activity in the distal internal sphincter muscle, which extends to the dentate line, confirm the diagnosis.

There are no large series of patients with UHD reported. However, multiple small series suggest that myectomy of a strip of the internal sphincter up to five to seven cm is effective in providing good stool evacuation. Anal dilations are not successful. Biofeedback therapy would not be expected to be successful given the abnormal manometry findings. Cecostomy does not address the actual pathology. An endorectal pull through may be unnecessary if myectomy was successful. However, myectomy should not preclude the ability to perform a pull through should it be unsuccessful.

[Tariq]

b

[Admin]

b

correct

Ultrashort segment Hirschsprung disease (UHD) is characterized by chronic constipation without classic findings of a transition zone on contrast enema. Some authors suggest that the diagnosis may be made on the basis of the clinical history and the absence of anal relaxation with rectal distention on rectal manometry with the presence of ganglion cells on rectal biopsy. Others might consider this to be internal anal spincter achalasia. In the scenario presented in the question, ganglion cells are absent for a very short segment with the presence of increased acetylcholinesterase (AChE) activity, thereby confirming the diagnosis of Hirschsprung disease. Criteria described by Meier-Ruge would indicate that UHD may extend up to six cm from the dentate line. These authors feel that confirmation of the diagnosis requires a full thickness biopsy, as ganglion cells may be absent in the submucosa of the very distal rectal and anal segment. The absence of ganglion cells and the increase of AChE activity in the distal internal sphincter muscle, which extends to the dentate line, confirm the diagnosis.

There are no large series of patients with UHD reported. However, multiple small series suggest that myectomy of a strip of the internal sphincter up to five to seven cm is effective in providing good stool evacuation. Anal dilations are not successful. Biofeedback therapy would not be expected to be successful given the abnormal manometry findings. Cecostomy does not address the actual pathology. An endorectal pull through may be unnecessary if myectomy was successful. However, myectomy should not preclude the ability to perform a pull through should it be unsuccessful.