Abstract
Introduction A biopsy protocol for diagnosing Hirschsprung's disease (HD) in children using the
anorectal line (ARL).
Materials and Methods The ARL was adopted for diagnosing HD in 2016 using two excisional submucosal rectal
biopsies performed at different levels, sequentially; the first just above the ARL
and the second, further proximal (2-ARL). Currently, only the first-level biopsy is
performed (1-ARL) and examined intraoperatively. Management was observation if normoganglionic,
pull-through if aganglionic, and a second-level biopsy if hypoganglionic. Hypoganglionosis
was considered physiologic if the second-level biopsy was normoganglionic and pathologic
if hypoganglionic. Colon caliber change and bowel obstructive symptoms reflect the
severity of hypoganglionosis.
Results For 2-ARL (n = 54), results were: normoganglionosis (n = 31/54; 57.4%), aganglionosis (n = 19/54; 35.2%), and hypoganglionosis (n = 4/54; 7.4%); physiologic (n = 3/54; 5.6%) and pathologic (n = 1/54; 1.9%). Normoganglionosis and aganglionosis were always duplicated in 2-ARL
(kappa = 1.0). For 1-ARL (n = 36), results were: normoganglionosis (n = 17/36; 47.2%), aganglionosis (n = 17/36; 47.2%), and hypoganglionosis (n = 2/36; 5.6%). Second-level biopsies were normoganglionic (physiologic: n = 1) and hypoganglionic (pathologic: n = 1). All normoganglionic cases, except one, resolved conservatively. All aganglionic
cases had pull-through with HD confirmed on histopathology. Both pathologic hypoganglionic
cases had caliber change and severe obstructive symptoms as definitive indications
for pull-through with hypoganglionosis of the entire rectum confirmed on histopathology.
Physiologic hypoganglionic cases were observed and currently have regular defecation.
Conclusion Because the ARL is an objective functional, neurologic, and anatomic demarcation,
normoganglionosis and aganglionosis can be diagnosed accurately with a single excisional
biopsy. Only hypoganglionosis requires a second-level biopsy.
Keywords
Hirschsprung's disease - anorectal line - aganglionosis - hypoganglionosis - rectal
biopsy
