Problems in fast intraoperative diagnosis in Hirschsprung's disease.

Histopathological evaluation of the proximal segment in colonic resections/biopsies for Hirschsprung's disease (HD) is very important because of the strong link between proximal segment histology and postoperative outcome. Therefore, we investigated whether a recently described rapid immunohistochemical staining technique using EnVision-antibody-complex is suitable for intraoperative diagnosis during surgery in HD. Various antibodies were applied on frozen sections from 20 colonic tissue samples including aganglionic segments, segments from the transitional zone, and normally innervated bowel segments to show ganglion cells (GCs) and cholinergic fibres. Several antibodies revealed positive staining of GCs (neurofilament, synaptophysin, peripherin, neural cell adhesion molecule/NCAM/CD56). However, none of these antibodies selectively identifies GCs. Microtubuli-associated protein 2/MAP2 stained few GCs only when incubation times were extensively prolonged. The antibodies applied to determine cholinergic innervation by immunohistochemistry (Acetylcholinesterase/AChE, cholinergic Acetyltransferase/chAT) failed. Rapid immunohistochemical technique using EnVision-antibody-complex on frozen sections of the large bowel is a) suitable for detection of many diverse antigens, including several neuronal antigens, b) not helpful to prove the presence or the absence of ganglion cells with any of the antibodies applied, c) not suitable to display the cholinergic innervation and iv) therefore is not helpful to shorten the consumption time during surgery in HD.