Current Treatment Options for Children with Hirschsprung's Disease

Hirschsprung's disease usually presents in one of three ways:

• Distal intestinal obstruction in newborns:
  • Symptoms in newborns may include abdominal distension, vomiting and feeding intolerance. A delay in the passage of meconium is present in approximately 90 percent of newborns.
  • Chronic and severe constipation in older children.
  • Enterocolitis in children of all ages.

The first step in diagnosing a newborn with a clinical picture of Hirschsprung's disease is to obtain a contrast enema using water-soluble material. If Hirschsprung disease is suspected based on diagnostic findings, a suction rectal biopsy will be performed to confirm a diagnosis. This is a low risk procedure that can be done at the bedside or in the clinic.

Diagnosing Hirschsprung's Disease in Older Children

Not every child with Hirschsprung's disease will have immediate symptoms at birth. Some children begin to show symptoms as they wean off of breastfeeding or develop chronic constipation when they become toddlers. Although many children experience constipation, those with Hirschsprung's disease fail to thrive, have extreme abdominal distention and sometimes depend on enemas to empty. Those with significant watery stools may have enterocolitis. Children who do not respond well to less invasive treatments such as enemas, laxatives and behavior modification, should be referred to a specialist for evaluation.

Another diagnostic technique to employ with older children is the use of anorectal manometry to look for the presence of the rectoanal inhibitory reflex (RAIR)—which is always absent in children with Hirschsprung's disease. Typically the smooth muscle of the internal sphincter relaxes when stool distends the rectum. In Hirschsprung's disease, the internal sphincter instead tightens worsening the obstructive symptoms. If there is an absence of a RAIR, a rectal biopsy should be performed.

In rare cases, children with Hirschsprung's disease will have symptoms that include fever, abdominal distention and diarrhea due to Hirschsprung-associated enterocolitis (HAEC). HAEC can be chronic, severe and sometimes life threatening. Since constipation is usually a sign of Hirschsprung's disease, children with diarrhea may not be considered for a diagnosis. It’s very important to consider the child’s history including failure to pass meconium in the first 24 hours of life as well as any past obstructive episodes.

There are a variety of congenital abnormalities that are associated with Hirschsprung's disease that a diagnosing physician should look for. These conditions include:

• Congenital heart disease
• Congenital central hypoventilation syndrome
• Cleft lip and palate
• Dysmorphic features
• Endocrine neoplasia
• Genitourinary abnormalities
• Hearing loss
• Limb abnormalities
• Malrotation
• Mental retardation
• Neurocristopathies
• Trisomy 21

Children with these conditions who present with neonatal bowel obstruction, chronic constipation or symptoms of enterocolitis should be assessed for Hirschsprung's disease.

Once a diagnosis of Hirschsprung's disease is made, surgery to remove the aganglionic bowel is performed.

Surgical correction is done using one of several reconstructive techniques, and in most cases can be successfully performed without a preliminary colostomy or a major abdominal incision. Surgery is performed using the latest laparoscopic techniques to reduce the risk of complications, allow for shorter hospital stays and result in a faster recovery.
Prior to surgery, newborns with intestinal obstruction and children with enterocolitis should have a nasogastric tube placed and receive intravenous fluids with broad-spectrum antibiotics.

Surgical Procedures for Hirschsprung's Disease

The most commonly performed “pull-through” surgical procedures are:

• Swenson: During the Swenson procedure, the full thickness of rectum is removed and the normally innervated bowel is anastomosed just above the anal sphincter.
• Duhamel: During the Duhamel procedure, the plane behind the rectum is developed and the normally innervated bowel is brought down and anastomosed to the back of the native aganglionic rectum just above the anal sphincter. A stapler is then used to connect the two lumens, so that the final result is a tube which consists of aganglionic rectum anteriorly and normally innervated bowel posteriorly.
• Soave: During the Soave procedure, the mucosa is stripped from the underlying muscle and the normally innervated bowel is brought through the rectal muscular “cuff” and anastomosed just above the anal sphincter. This surgery was designed to prevent injury to pelvic nerves and blood vessels.

Many children thrive after surgery for Hirschsprung's disease and experience normal bowel function and an improved quality of life. Initially, loose stools may occur in the early postoperative period, but eventually will improve over time as the child heals. For some children, Hirschsprung-associated enterocolitis (HAEC) and functional problems (such as ongoing bowel obstructive symptoms and soiling) continues to occur.

Symptoms of Hirschsprung-Associated Enterocolitis

It is imperative that family members and primary care physicians stay alert to the symptoms of HAEC. HAEC can come on suddenly and result in sepsis and possible death if left untreated.

Symptoms include:

• Bloating
• Fever
• Lethargy
• Poor feeding
• Rectal bleeding
• Severe diarrhea
• Vomiting

Symptoms of Functional Problems After Surgery for Hirschsprung's Disease

The two categories of functional problems for children post-surgery include ongoing obstructive symptoms and problems with soiling.

Obstructive symptoms include:

• Abdominal distention
• Bloating
• Borborygmi (stomach growling)
• Difficulty passing stools without the assistance of rectal stimulation or enemas
• Vomiting
• Ongoing severe constipation

Possible Causes of Functional Problems Following Surgery for Hirschsprung's Disease

There are five major reasons for persistent obstructive symptoms following a pull-through surgery. They include:

• Mechanical obstruction from a stricture or a twist of the pull-through
• A mega Duhamel pouch
• Persistent transition zone
• Non-relaxation of the internal anal sphincter
• Functional megacolon caused by stool-holding behavior

Soiling following a pull-through can be due to:

• Poor muscle function
• Poor bowel sensation
• Encopresis
• Hypermotility

An organized and methodical approach to diagnosing the issue is key to successfully managing symptoms and developing an appropriate treatment plan.

Even though post-surgical problems are fairly common, most children with Hirschsprung's disease eventually overcome these issues (usually in the first five years of life). Studies show that teenagers and adults with Hirschsprung's disease have normal rates of sexual function, social satisfaction and a good quality of life despite their past challenges.

Hirschsprung's disease is a complex and heterogenous disease. Our understanding of the genetic basis of Hirschsprung's disease is constantly evolving through our research.

Creation of a large database of patients with information about genetic mutations, pathological findings and clinical outcomes will be very important in furthering our understanding of the disease and optimizing our therapeutic strategies. One such database that is being developed is the Hirschsprung Disease Research Collaborative.

Stem cell research is also currently being conducted to attempt to repopulate the aganglionic bowel in children with Hirschsprung disease using neuronal stem cells. This novel research offers an exciting new treatment modality for children with Hirschsprung's disease, particularly for those with more severe forms of aganglionosis.

Through our continued research, education and implementation of the latest advanced technology in diagnostic and treatment techniques, pediatricians and primary care physicians will have all of the knowledge and tools necessary to successfully manage and treat children with Hirschsprung's disease.