Clinical and surgical aspects of Hirschsprung’s disease

Hirschsprung’s disease is an important cause of intestinal obstruction or constipation in newborns and children. It is characterized by lack of ganglion cells extending from distal in the internal anal sphincter to proximal in the colon or small bowel for a variable distance caused by arrest of migration of the ganglion cells from the neural crest. The classic extension of the aganglionosis is the rectosigmoid in 80% of cases, long segment varying from 11% to 26% and total colonic aganglionosis from 5% to 15%. Hirschsprung’s disease is not curable and all the different operative methods currently used leave a small segment of aganglionic bowel behind. The surgical treatment of Hirschsprung’s disease reduces the complications, morbidity and mortality related to the disease but does not restore the underlying disorder, namely the replacement of the neurons of the Enteric Nervous System. It is quite common that children, despite an adequate operative treatment for Hirschsprung’s disease, keep presenting with defecation disorders. This thesis analyses different aspects that could be involved in the causes of persisting motility and defecation disorders before and after the surgical treatment for Hirschsprung’s disease. We have learned that the proximal end of the resected specimen may tell us something about the functional outcome of Hirschsprung’s disease. The patients with aganglionosis and hypoganglionosis at the proximal remaining bowel have more chances to present defecation problems than patients with regular histology. The patients with neuronal intestinal dysplasia (NID B) have slightly higher chances to become constipated that tend to improve until the age of 4 years. We also observed that the more extended resection is, the less important becomes the histological findings of the proximal segment concerning the postoperative outcome. The laparoscopic approach to surgical management has no adverse effects and likely cosmesis in the future will become a key player in favor of laparoscopy. The patients with Down syndrome and Hirschsprung’s disease have more chance to present with postoperative complications such as anastomotic leakage and abscess formation than the children with isolated Hirschsprung’s disease. Furthermore, they have a higher constipation rate than the other children with Hirschsprung’s disease. Total aganglionosis is also a distinct group of Hirschsprung’s disease. This group tends to present with a higher morbidity and mortality rate than the classical Hirschsprung’s disease as well as problems related to extensive bowel resection such as diarrhea, perineal excoriation and short bowel. In three cases of extended aganglionosis until the mid ileum, in which the ileostomy was functioning well, we did not remove the complete aganglionic small bowel in order to avoid short bowel complications. The leaving of aganglionic bowel when the ileostomy function well is a novel alternative in the treatment of extended total aganglionosis that requires further studies. Sofar Hirschsprung’s disease has proven to be a not curable complex entity and there is still a lot to be learned and researched in order to achieve the best possible results for our patients.