DrBeen Medical Lectures: Dr. Marc Levitt, MD Discusses Hirschsprung Disease

Hirschsprung disease occurs in about 1 in 5000 live births.

90% of Hirschsprung patients are diagnosed in the first couple of months of life, the vast majority in the first week or so of life.

In Hirschsprung disease, ganglion cells have not migrated to the distal colon, and without ganglion cells the colon cannot relax and therefore stays squeezed.

Because the lining of the bowel is not normal in Hirschsprung disease, bacteria that stay in the colon can migrate out and get into the bloodstream, creating a life-threatening condition called enterocolitis.

If Hirschsprung disease is recognized, it is pretty straightforward to intervene; you do not necessarily need surgery to prevent enterocolitis, you just need good nursing care and proper irrigation to get the stool to flow.

About 5% of Hirschsprung patients present after 1 year of life; the vast majority present as babies.

Down syndrome is associated with Hirschsprung disease.

10% of patients with meconium plug actually have Hirschsprung disease as the underlying cause; 90% just pass the plug and get better.

Milk protein allergy can mimic Hirschsprung disease; if you biopsy looking for Hirschsprung, you will find ganglion cells but lots of eosinophils.

To confirm Hirschsprung disease, you need both the absence of ganglion cells and confirmation that the nerves associated with those ganglion cells are thickened (hypertrophic).

Nerve trunks greater than 40 microns are abnormal in rectal biopsy specimens.

You cannot diagnose Hirschsprung with a frozen section, but you can rule it out if ganglion cells are present. To prove it is Hirschsprung disease, you need several days and need to evaluate 100 slices of the sample.

In about 15% of Hirschsprung cases, the aganglionic segment extends higher than the splenic flexure.

Contrast enema is accurate in identifying the transition zone about 90% of the time, so when doing surgery, you need to confirm under the microscope where the healthy bowel begins.

The dilated colon in Hirschsprung disease will shrink down to more normal size as soon as it is given the opportunity to successfully empty out the anus once the blockade has been removed.

You really only need about 10% of your colon to function completely normally and have one bowel movement per day.

Most Hirschsprung patients only lose about 15 to 20% of their colon because that is where the abnormal segment is, so they can have a completely normal stooling life with one bowel movement per day.

Patients who have to lose their entire colon and have small bowel brought to the anus tend to have more frequent stools, somewhere between 2 and 6 per day, but can all maintain bowel control provided the surgeon successfully preserves the anal canal and sphincters.

Sometimes the irrigation tube does not reach high enough and does not get into the normal bowel, and therefore you cannot successfully decompress the bowel; such patients would benefit from a diversion with a stoma.

If a family has a baby with Hirschsprung disease, the risk of another baby having Hirschsprung disease in their family is about 1 in 200, significantly higher than the general population risk of 1 in 5000.

Hirschsprung-associated enterocolitis is treated with irrigations, metronidazole antibiotic (for anaerobic bacteria), and intravenous hydration.

Even after successful Hirschsprung surgery, you are in danger of getting enterocolitis if you do not have good flow, and the sphincters can slow down the flow enough that you can develop enterocolitis even after surgery.

If you give Botox to temporarily knock out the sphincters (the Botox wears off over the next 3 months), the baby can learn to push on their abdomen and overcome the non-relaxing sphincters.

In Hirschsprung disease, the internal sphincter does not relax normally. When you have fullness in your rectum, your internal sphincter is supposed to relax, but in Hirschsprung disease it tightens at the wrong time and can hold stool in at an inappropriate time.

The vast majority of Hirschsprung patients recover very uneventfully, stool normally, and when they get to age 3 or 4 they successfully potty train.

Hirschsprung disease is a source of significant morbidity and mortality in the developing world if it is unrecognized.