Endoscopic Mucosal Resection for the Diagnosis of a-Ganglionosis, a Controlled Prospective Trial (EDGE Trial)

Background: Adult and pediatric patients presenting with chronic constipation and/or motility disorders may be referred for rectal biopsy to rule out aganglionosis or Hirschsprung's disease. The traditional diagnostic test, rectal suction biopsy, is a blind technique and is insensitive in confirming the diagnosis. Frequently, patients require subsequent referral for a surgical full thickness biopsy.

Hypothesis: Endoscopic mucosal resection (EMR) will improve the diagnostic yield for aganglionosis and decrease the need for subsequent surgical full thickness biopsy.

Methods: This is a prospective, single center, controlled investigation of EMR for the diagnosis of colonic aganglionosis / Hirschsprung's disease. Patients who are offered rectal suction biopsy will be offered enrollment. Enrolled patients will have one additional procedure (EMR) at the time of their rectal suction biopsy. Specimens will be analyzed pathologically for size, submucosal tissue adequacy, the presence of ganglionic tissue, and positivity by acetylcholinesterase staining. The adequacy of the tissue specimen, the proportion of diagnostic specimens, and the proportion of patients that would have required subsequent referral for full thickness biopsy, will be compared. Variable such as cost and recovery time will be compared. Biopsy results will be compared with patient's pre-endoscopy clinical data including their history of constipation, results of SITZ marker studies, Bristol stool scale, and anorectal manometry.

Results: The primary outcome variable will be the proportion of patients with a diagnostic specimen in each group. Secondary outcome variables will include the size of the specimen, the presence of ganglionic tissue, the presence of submucosal tissue, and the positivity of the acetylcholinesterase stain. The biopsy results will also be correlated with patient's clinical data including clinical history, Bristol stool scale, anorectal manometry results, and SITZ marker studies. Cost and recovery time will be compared.

Discussion: The proposed investigation may demonstrate that a simple endoscopic test, which uses direct visualization, can improve the diagnostic yield of rectal biopsies for Hirschsprung's disease, and spare patients an additional surgical full thickness rectal biopsy.