Abnormal distribution of nerve terminals in the normoganglionic bowel of Hirschsprung's disease: a causative factor of failed pull-through operations?

The aim of this study was to examine the innervation pattern of the muscle layers of normoganglionic pulled-through bowel in patients with Hirschsprung's disease (HD) by observing the distribution of nerve terminals comprising neuromuscular junctions and synapses. As a marker for nerve terminals, monoclonal antibody (MAb) 171B5 was used. Pulled-through normoganglionic bowel from 12 patients with HD that was either biopsied or resected at operation and normal bowel specimens from 7 age-matched controls were labelled using an immuno-histochemical technique with MAb 171B5. In all specimens of the control group and 9 patients of the HD group, numerous neuromuscular junctions were demonstrated in the muscle layers of the normoganglionic bowel and numerous synapses in the myenteric plexuses. However, in the specimens of 3 patients of the HD group abnormal distribution of nerve terminals was seen in the normoganglionic bowel. Two of these 3 patients had abnormal postoperative defecation. Based on our study, there appears to be a small number of HD patients who have an innervation disorder of the muscle layers in the proximal, normoganglionic bowel pulled through at surgery, which hitherto have been thought to be normal.