Biopsy Diagnosis of Hirschsprung's Disease Using a Single Excisional Biopsy Based on the Anorectal Line.

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.