Histopathological perspective of the pulled-through colon in Hirschsprung disease: Impact on clinical outcome.

BACKGROUND: The outcome in HD has not been always satisfactory even after a technically sound operation. PURPOSE: To define the characteristic histopathological features of the pulled-through colon in patients with HD, and it is impact on clinical outcome. PATIENTS AND METHODS: The study included patients with HD who underwent surgical repair between 2010 through 2016. The proximal margin of resected bowel segments (which corresponds to the pulled through colon) was subjected to detailed histopathological examination by two experienced pathologists. Based on the frequency of postoperative attacks of HAEC (fever, vomiting, abdominal distention, fluid offensive stools), cases included in the study were divided into two groups: Group A, those with less frequent attacks of HAEC; and Group B, those with recurrent attacks of HAEC (more than 3). RESULTS: The study included 35 patients (25 in group A; and 10 in group B). Their age ranged from 0.2 to 144 months (median 6 months). Comparing the histopathological findings in the two clinical groups, we have found that Group B (recurrent attacks of HAEC) had significantly more frequent focal disarray of nerve bundles and thicker nerve bundle diameter. Also, histopathological features of acute inflammation were more prevalent in examined specimens from group B. CONCLUSION: Several histopathological features of the examined bowel specimens in HD, other than presence or absence of ganglion cells, are indicative of postoperative functional outcome. These include the thickness and maturity of nerve bundles, in addition to the presence of histopathological features of acute inflammation. LEVEL OF EVIDENCE: This is a case control study (level III evidence).