Hirschsprung’s disease

Hirschsprung’s disease (HD) is a disorder of the abdomen that occurs when part or all of the large intestine or antecedent parts of the gastrointestinal tract have no nerves and therefore cannot function.

During normal fetal development, cells from the neural crest migrate into the large intestine (colon) to form the networks of nerves called Auerbach’s plexus and Meissner’s plexus. In Hirschprung’s disease, the migration is not complete and part of the colon lacks these nerve bodies that regulate the activity of the colon. The affected segment of the colon cannot contract and therefore pass stool through the colon, creating an obstruction. In most affected people, the disorder affects the part of the colon that is nearest the anus. In rare cases, the lack of nerve bodies involves more of the colon. In five percent of cases, the entire colon is affected. Stomach and esophagus may be affected too. Hirschsprung’s disease is also sometimes called congenital aganglionic megacolon.

Hirschsprung’s disease occurs in about one in 5,000 children (U.S. and Japan). It is usually diagnosed in children, and affects boys more often than girls.

History and description

The first report of Hirschsprung disease dates back to 1691, however, the disease is named after Harald Hirschsprung, the Danish physician who first described two infants who died of this disorder in 1888.

Hirschsprung’s disease is a congenital disorder of the colon in which certain nerve cells, known as ganglion cells, are absent, causing chronic constipation. The lack of ganglion cells is in the myenteric plexus (Auerbach’s Plexus), which is responsible for moving food in the intestine. A barium enema is the mainstay of diagnosis of Hirschsprung’s, though a rectal biopsy showing the lack of ganglion cells is the only certain method of diagnosis.

The usual treatment is “pull-through” surgery where the portion of the colon that does have nerve cells is pulled through and sewn over the part that lacks nerve cells. For a long time, Hirschsprung’s was considered a multi-factorial disorder, where a combination of nature and nurture were considered to be the cause. However, in August 1993, two articles by independent groups in Nature Genetics said that Hirschsprung’s disease could be mapped to a stretch of chromosome 10.

Epidemiology

According to a 1984 study conducted in Maryland, Hirschsprung’s disease appears on 18.6 per 100,000 live births. In Japan, Hirschsprung disease occurs in about one in 5,000 births. It is more common in male rather than female (4.32:1) and in white rather than non-white. Nine percent of the Hirschsprung cases were also diagnosed as having Down syndrome. Most cases are diagnosed before the patient is 10 years of age.

Hirschsprung’s disease can also present as part of a syndrome in Waardenburg-Shah syndrome, Mowat-Wilson syndrome, Goldberg-Shpritzen megacolon syndrome, and congenital central hypoventilation syndrome.

Typically, Hirschsprung’s disease is diagnosed shortly after birth, although it may develop well into adulthood, because of the presence of megacolon, or because the baby fails to pass the first stool within 48 hours of delivery. Normally, 90% of babies pass their first stool within 24 hours, and 99% within 48 hours. Other symptoms include: green or brown vomit, explosive stools after a doctor inserts a finger into the rectum, swelling of the abdomen, lots of gas and bloody diarrhea.

Diagnosis

Definitive diagnosis is made by suction biopsy of the distally narrowed segment. A histologic examination of the tissue would show a lack of ganglionic nerve cells. Diagnostic techniques involveanorectal manometry, barium enema, and rectal biopsy. The suction rectal biopsy is considered the current international gold standard in the diagnosis of Hirschsprung’s disease.

Treatment

Treatment of Hirschsprung’s disease consists of surgical removal (resection) of the abnormal section of the colon, followed by reanastomosis.

Colostomy

The first stage of treatment used to be a reversible colostomy. In this approach, the healthy end of the large intestine is cut and attached to an opening created on the front of the abdomen. The contents of the bowel are discharged through the hole in the abdomen and into a bag. Later, when the child’s weight, age, and condition is right, the “new” functional end of the bowel is connected with the anus.

Swenson, Soave, Duhamel, and Boley procedures

Orvar Swenson, who discovered the cause of Hirschsprung’s, first performed its surgical treatment, the pull-through surgery in 1948. The pull-through procedure repairs the colon by connecting the functioning portion of the bowel to the anus. The pull-through procedure is the typical method for treating Hirschsprung’s in younger patients. Swenson devised the original procedure, and the pull-through surgery has been modified many times.

Currently, there are several different surgical approaches, which include: the Swenson, Soave, Duhamel, and Boley procedures. The Swenson procedure leaves a small portion of the diseased bowel. The Soave procedure leaves the outer wall of the colon unaltered. The Boley procedure is a small modification of the Soave procedure, so the term “Soave-Boley” procedure is sometimes used. The Duhamel procedure uses a surgical stapler to connect the good and bad bowel.

For the 15 percent of children who do not obtain full bowel control, other treatments are available. Constipation may be remedied by laxatives or a high fiber diet. In these patients, serious dehydration can play a major factor in their lifestyle. A lack of bowel control may be addressed by a stoma, similar to a colostomy. The Malone antegrade colonic enema (ACE) is also an option. In a Malone ACE, a tube goes through the abdominal wall to the appendix or, if available, to the colon. The bowel is then flushed daily. Children as young as 6 years of age may administer this daily flush on their own.

If the affected portion of the lower intestine is restricted to the lower portion of the rectum, other surgical procedures may be performed, such as a posterior rectal myectomy.

The prognosis is good in 17 percent of cases. Chronic post-operative constipation is present in 7 to 8 percent of the operated cases. Post-operative enterocolitis is a severe manifestation that is present in the 10%–20% of operated patients.