Hirschsprung Disease

Abstract

Hirschsprung disease is a developmental disorder of the enteric nervous system that is characterized by the absence of ganglion cells in the myenteric and submucosal plexuses of the distal intestine. This results in absent peristalsis in the affected bowel and the development of a functional intestinal obstruction. In most cases, the aganglionosis involves the rectum or rectosigmoid, but it can extend for varying lengths and in 5–10% of cases can involve the entire colon or even a significant amount of the small intestine. The incidence of Hirschsprung disease is approximately one in 5,000 live born infants.

Appendices

Summary Points

Hirschsprung disease must be considered in any neonate with distal intestinal obstruction, or any older child with persistent severe constipation or enterocolitis.

Although the diagnosis can be suspected on the basis of history, physical examination, and radiology, the gold standard for diagnosis is an adequate rectal biopsy showing aganglionosis.

Most children can be treated with a one-stage pull-through procedure, although a stoma may still be appropriate for those with severe enterocolitis, malnutrition, massive colonic distention, inadequate pathology support, or long-segment disease.

The Swenson, Soave, and Duhamel procedures are all excellent, and the surgeon should do the operation that he/she is trained to do and does frequently. The laparoscopic and transanal approaches are associated with less pain, earlier feeding, and shorter hospital stay than the open procedures.

When doing a laparoscopic or transanal pull-through, a preliminary biopsy should be done to identify the pathological transition zone prior to beginning the anal dissection. This can be done laparoscopically or through an umbilical incision.

Many patients will have ongoing problems after a pull-through, including obstructive symptoms, incontinence, and enterocolitis. An organized approach to diagnosing and managing these complications is essential.

Patients with long-segment disease, trisomy 21, and other syndromes and anomalies are at higher risk for problems and complications.

Editor’s Comment

When done by experienced surgeons, the clinical outcomes of the various operations for the treatment of Hirschsprung disease are all quite similar. It is therefore important to become very familiar with one of the procedures described. I prefer the transanal Soave, with laparoscopic assistance when the transition zone is in question or if the splenic flexure needs to be taken down to mobilize the distal colon. I try to avoid colostomies whenever possible, but for infants with total colonic aganglionosis I perform an ileostomy followed by an ileal Duhamel between 6 and 12 months of age. Likewise, I will usually recommend a temporary colostomy for children who present late and have a true megacolon and most patients with trisomy 21.

It is important to realize that the operation for Hirschsprung disease is not curative, but rather palliative. Most children continue to have some degree of constipation and are at risk for enterocolitis. This is probably due to the fact that the sphincter is abnormal, the recto-anal reflex remains dysfunctional, and, as research has shown, there is more to this disease than simply a lack of ganglion cells. Nevertheless, most patients can function reasonably normally and do well in the long term. The exceptions are patients with long-segment ­disease and those with trisomy 21, who generally do quite poorly for a long time, though most seem to improve eventually.

When a patient fails, it is important to do a rectal biopsy to rule out recurrent aganglionosis, even though we fear that others will be critical of our initial operation. Although some few cases might appropriately be blamed on surgeon or pathologist error, in many cases there is clearly an as yet unexplained and mysterious process at work (ischemia? denervation?) that causes ganglion cells to disappear. These patients are probably best served by redoing the pull-through, which, if enough time has passed, is not always as difficult as one would expect. To avoid pulling through the transition zone, it is important to rely on the intra-operative biopsies and ignore the results of the contrast enema. Finally, when performing a Soave procedure, it is probably best to avoid excessive stretching of the anal sphincter, create only a short muscular cuff, and always perform a complete myotomy of the cuff in the midline posteriorly.

Differential Diagnosis

Neonatal presentation

Meconium ileus

Intestinal atresia

Meconium plug syndrome

Obstructing congenital band

High anorectal malformation

Motility disorder/intestinal pseudo-obstruction

Systemic problem (i.e., septic ileus, hypothyroidism, electrolyte disorder)

Chronic constipation

Colonic motility disorder

Internal sphincter achalasia

Intestinal neuronal dysplasia/hypoganglionosis/desmosis coli

Functional megacolon/stool-holding behavior

Enterocolitis

Gastroenteritis

Malabsorption

Necrotizing enterocolitis

Malrotation and volvulus

Congenital chloride diarrhea

Diagnostic Studies

Plain abdominal radiograph

Contrast enema

Anorectal manometry

Rectal biopsy

Parental Preparation

The diagnosis of Hirschsprung disease can only be confirmed by rectal biopsy.

A temporary colostomy is sometimes necessary to increase the likelihood of a good long-term result.

Most children with Hirschsprung disease do well and live a full and normal life, but some have ongoing problems.

Preoperative Preparation

Make sure the diagnosis is definitive, based on review of the rectal biopsy by an experienced pediatric pathologist

Settle down any enterocolitis by using antibiotics and bowel irrigation

Preoperative prophylactic antibiotics

Informed consent

Technical Points

Wash out rectum and distal colon in the operating room prior to beginning.

Preliminary biopsy to determine normal ganglion cells using either laparoscopy or umbilical incision.

Start mucosal incision 5–10 mm from dentate line, depending on the size of the child. Making the anastomosis too low will predispose to incontinence from interference with sensation, and making the anastomosis too high will predispose to persistent obstructive symptoms.

Make a short rectal cuff, no more than 2–3 cm long. If you do make a longer cuff, make sure to divide it before completing the pull-through.

Once in the extra-rectal space, keep dissection right on the wall of the colon.

Divide bowel and do anastomosis at least 2 cm above the biopsy showing normal ganglion cells, to avoid a transition zone pull-through.