Historical aspects of anatomic landmarks during pull-through for hirschsprung disease: focusing on resection levels of the aganglionic rectum and rectal cuff issues.

The historical legacy of using fixed distances from the dentate line (DL) for rectal resection during pull-through for Hirschsprung's disease (HD) has never really been investigated despite widespread continuous use. Swenson initially used 1.5-2.0 cm from the anal verge for resection. In 1962, Bill and Chapman reported an association between residual aganglionic segments, obstructive symptoms, and postoperative enterocolitis. In 1964, Swenson modified his resection to 1.5-2.0 cm from the DL anteriorly and 1.0 cm or less posteriorly. Other master surgeons also explored lines for rectal resection; however almost all were based on anecdotal experience. More recently, possible associations between resection lines and postoperative complications were reported by De la Torre (2017) and a nationwide survey in Japan (2019). In 2007, co-author AY adopted the anorectal line (ARL) exclusively as an alternative to the DL specifically because it was readily identifiable, independent of age/build, functionally relevant as the distal margin of the enteric nervous system, and indispensable for normal anal sensation as the upper border of the anal transitional zone histopathologically. While the anal verge and the DL have been important historically, the ARL objectively enhances the reliability of rectal resection of the aganglionic segment without causing injury to the anal transitional zone.