Hirschsprung Disease The 5 Minute Pediatric Consult


	Hirschsprung Disease

Helen Anita John-Kelly and Andrew E. Mulberg

Database
Data Gathering
Physical Examination
Laboratory Aids
Therapy
Bibliography

DATABASE

DEFINITION

Intestinal abnormality of abnormal innervation of the distal bowel beginning at the anus and extending proximately for a variable distance causing partial or complete intestinal obstruction, difficulty in passing stools and in some cases enterocolitis.
Also known as congenital megacolon and was first reported by Harold Hirschsprung in 1886.
Present as complete obstruction, delayed passage of meconium, “chronic constipation,” or enterocolitis.

PATHOPHYSIOLOGY

Basic histological finding is the absence of Meissner and Auerbach plexuses, hypertrophied nerve bundles between the circular and the longitudinal muscles and in the submucosa.
Defect considered as a failure of caudal migration of the neural crest cells.

GENETICS

Possible gene locus on the long arm of chromosome 10. Recent mouse models suggest a defect in the endothelin receptor.

EPIDEMIOLOGY

Most common cause of lower intestinal obstruction in neonates: 1 in 5000 births
Overall rate of male:female patients is 2.8:1; in long-segment disease, it is 2.8:1 and in total colonic aganglionosis, it is 2.2:1.
No racial predilection
Familial incidence in total colonic aganglionosis: 75% of cases, rectosigmoid involved, 14%, descending colon involved; 8%, colon involved; 3%, small bowel affected.

ASSOCIATED DISEASES

In 3% of the patients, there has been an association with Down syndrome, cardiac anomalies, and coexistent multiple neuroblastomas.

DATA GATHERING

HISTORY

Question: Age of presentation
Significance: 80% of the time patients present in the neonatal period.

Question: Typical symptoms
Significance: Failure to pass meconium by 48 hours of life; delayed passage of meconium after 24 hours of life; history of constipation; history of chronic laxative use, abdominal distention, bilious vomiting, diarrhea in 22% of patients.

Question: Growth pattern
Significance: Neonates usually have normal weight, but growth retardation may occur when the disease is severe.

PHYSICAL EXAMINATION

Finding: On rectal examination, the sphincter is usually normal or increased.
Significance: Removal of the finger may be followed by explosive diarrhea; transition zone is usually not felt in infants under 2 months of age.

Finding: Stool in rectum.
Significance: In most instances, especially in older children, the rectum is empty.

Finding: Anemic?
Significance: Patients are usually anemic due to chronic blood loss from the large bowel secondary to infection.

LABORATORY AIDS

TESTS

Test: Complete blood count
Significance: Anemia, leukocytosis in the presence of enterocolitis.

Test: Plain film of abdomen
Significance: May show distended loops of colon. Small bowel air is usually present in the bowel proximal to the obstruction.

Test: Barium enema
Significance: Useful but not diagnostic; transition zone is a funnel-shaped area of intestine with normal distal area and dilated proximal area. Barium enema reveals large mucosal pattern, prominently thickened folds and irregular margins secondary to ulceration.

Test: Anorectal manometry
Significance: Diagnostic but usually reserved for those cases causing diagnostic difficulties, as in the ultrashort segment disease.

Test: Biopsy
Significance: Suction biopsy should be done approximately 2 to 4 cm from the anal verge depending on the age of the patient. The biopsies must have adequate submucosa to demonstrate neurofibrils detected using acetylcholinesterase as a stain. With the absence of ganglion cells, biopsy is diagnostic. If the suction biopsies are not conclusive, a full-thickness biopsy is mandatory.

COMPLICATIONS

Enterocolitis is the most important complication:

Secondary to obstruction causing an increase in intraluminal pressure and decreased intramural capillary blood flow.
Affects the protective mucosal barrier enabling fecal breakdown products, bacteria, and toxins, to enter into the bloodstream.
Usually present with fever, diarrhea, and frequent, bloody, bilious vomiting.

THERAPY

Stabilizing treatment is fluid resuscitation, nasogastric decompression, broad-spectrum antibiotics, and saline enemas.
The initial operation is a defunctionalizing colostomy or an ileostomy for total colonic aganglionosis. This is performed to avoid the hazards of enterocolitis. If the child has already developed enterocolitis, colostomy is deferred untilthe general condition improves.
Definitive surgery is performed 6 months to a year after the initial colostomy. The various surgical procedures performed are:
- Endorectal pull-through: widely used. Basic principle is to strip the aganglionic rectum of its mucosa and then to bring normally innervated colon through the residual rectal muscular cuff, thereby bypassing the abnormal bowel from within. Advantages: sphincter function is preserved and minimal danger of injury to pelvis.
- Retrorectal transanal pull-through (Duhamel procedure): The normally innervated bowel is brought behind the abnormally innervated rectum approximately 1 to 2 cm above the pectinate line and an end-to-side anastomosis is performed. This procedure creates a neorectum with the anterior one-half having normal sensory receptors and a posterior one-half with normal propulsion. Advantages: reduces pelvic dissection to a minimum and retains the sensory pathway of rectal reflexes. Disadvantages: incontinence if anastomosis is too low and obstructive symptoms if anastomosis is too high or if the aganglionic segment is too long.
Other procedures include the Soave (endorectal pull through).
In total colonic aganglionosis, the modified Lester Martin technique is performed. It involves the anastomosis of the cecum and ascending colon as an on-lay patch graft in the more distal normal small bowel, which is then pulled through the amputated rectum that has been stripped of its mucosa and a primary anastomosis is performed.

PITFALLS

Early recognition is of utmost importance in reducing the morbidity and mortality of Hirschsprung disease.

BIBLIOGRAPHY

Abi-Hanna A, Lake AM. Constipation and encopresis in childhood. Pediatr Rev 1998;19(1):23–30.

Athow AL, Filipe MI, Drake DP. Problems and advantages of acetyl cholinesterase histochemistry of rectal suction biopsies in Hirschsprung’s disease. J Pediatr Surg 1990;25(5):520–526.

Diseth TH, Egeland T, Emblem R. Effects of anal invasive treatment and incontinence on mental health and psychosocial functioning of adolescents with Hirschsprung’s disease and low anorectal anomalies. J Pediatr Surg 1998;33(3):468–475.

Fitzgerald CJ. New concepts of the etiology, diagnosis, and treatment of congenital megacolon (Hirschsprung’s disease), by Orvar Swenson, MD, et al., Pediatrics, 1949;4:201–209. Pediatrics 1998;102(1 Pt 2):205–207.

Lyonnet S, Bolino A, Pelet A, et al. A gene for Hirschsprung’s disease maps to the proximal long arm of chromosome 10. Nature Genet 1993;4(4):346–501.

Mahboubi S, Schnaufer L. The barium enema and rectal manometry in Hirschsprung’s disease. Radiology 1979;130:643–647.

So HB, Becker JM, Schwartz DL, Kutin ND. Eighteen years’ experience with neonatal Hirschsprung’s disease treated by endorectal pull-through without colostomy. J Pediatr Surg 1998;33(5):673–675.

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