Hirschsprung Disease

Original Editor - Khloud Shreif
Top Contributors - Khloud Shreif, Vidya Acharya and Alexandra Stead

Introduction

Hirschsprung Disease (HD) was described for first time in 1888 by Harald Hirschsprung as a congenital aganglionic megacolon in which there are missed intestinal nerve cells (ganglion cells that are normally presented along the pathway of large intestine) in baby's large intestine. Theses cells help in the peristaltic movement of colon and when they are absent, theses nerve cells cause obstruction in bowel movement and difficulty passing stool in the neonates.

It is typically diagnosed within 48 hours after birth, when the baby fails to pass a stool. In mild cases, it may be diagnosed in adulthood, though rarely found in children over the age of 10 years old.

Aetiology

The aetiology of Hirschsprung is still not understood; there is evidence that suggests there is a significant genetic factor, particularly in cases of a large affected segment. Another theory suggests a familial risk is elevated when one of the parents, especially the mother, carries the condition, and if one child is affected, about 3-12% of children of the same parents have a probability to develop the disease.

Pathological Process

Short segment HD

There are two suggested mechanisms that explain the developmental failure of ganglion cells in parts of the large intestine (aganglionosis):

1. Failure of neuroblasts migration that travel from the neural crest near the spinal cord to reach the entire length of the intestine. This migration normally starts from the top down, in Hirschsprung the migration stops before the end of the colon, leaving the distal parts without nerve cells.
2. Nerve cells degeneration may happen; however, migration was finished successfully, but cells could not survive after arrival

There are 4 classifications according to the aganglionic segment:

1. Short segment disease (~75%): involvement of rectal and distal sigmoid colon only
2. Long segment(~15%): extends to the splenic flexure or the transverse colon.
3. Total colonic aganglionosis (range 2-13%): known as Zuelzer-Wilson syndrome and may extend into the small intestine.
4. Ultra- short segment disease: about 3-4 cm of the internal anal sphincter only affected.

Clinical Presentation

Symptoms and clinical presentation depend on how much the large intestine is affected and the age of the child. Approximately 90% of children with Hirschsprung's disease will experience symptoms in the first six weeks of life, usually after 48h from birth. Children with short-segment affection of intestine may not be diagnosed for several months or years, and their primary symptom will be constipation.

Common symptoms in infants:

• Failure to have a bowel movement in the first 48 hours of life
• Abdominal distention >90%
• Gradual onset of vomiting
• Fever because of enterocolitis can occur
• Constipation or failure to pass regular bowel movements

Common symptoms in children who don’t have early symptoms for months or years:

• Constipation that gets worse with time
• Loss of appetite
• failure to gain weight
• Delayed growth
• Passing small, watery stools
• Abdominal distention
• Fatigue
• Stomach pain

Diagnostic Procedures

Barium enema

• Contrast enema
• Rectal biopsy
• Abdominal X-ray
• Colonic transit study
• Anal manometry

Surgical Interventions

Resection of anorectal segment, narrow distal end (rectum) is on the left, and the proximal dilated end (sigmoid) is on the right.

Pull-through surgery

Pull-through surgery is one step and primary surgical intervention, the aganglionic segment is removed, and the remnant healthy colonic segment is pulled down through the remaining muscular cuff and sutured directly to the anus. It is done transanal with no need for abdominal incisions.

Ostomy Surgery

Ostomy Surgery is a two-step procedure, done in severe cases. First, the aganglionic segment is removed, then the healthy part is pulled through the stoma (opening made in the abdomen), which will be temporary to give time for the lower part of the intestine to heal. After several weeks or months, after recovery and healing, a second surgery is performed. In this operation, the stoma is closed, and the healthy segment is connected to the rectum or anus.

Care after surgery

The majority of children improve and are able to pass stool after surgery. However, there are some children who may experience constipation.

An increase in fluid intake and keeping the child hydrated is recommended. They are advised to concentrate in food rich in fibres but a gradual increase in fibre intake is recommended, and avoid sudden increases in high-fibre foods. In addition, concentrate on whole grains, fruits, and vegetables, and limit white bread.

Daily physical activity is also recommended to help with bowel movement.

Some possible complications after surgery, like constipation, diarrhoea, and leaking stool, may get better with time. However, symptoms like fever, abdominal bloating, bleeding from the rectum, or vomiting will need to be taken care of.

Pelvic Floor Physiotherapy

Physiotherapy should start early postoperative for early mobilisation, to help with respiratory function, decrease time of hospitalisation and accelerate gastrointestinal recovery. Patients undergone ostomy surgery may complain of abdominal muscle weakness, increased breathing effort, hip pain, decreased hip joint movement and impairment to their daily activities.

Different breathing exercise techniques, chest and thoracic expansion exercises, and teaching huffing and coughing to help the patient clear secretions. Encourage gradual return to activities such as walking and functional training, core strengthening, static abdominal exercise, and gradual progress to isotonic resisted exercises.

Pelvic floor muscle training and biofeedback to improve strength, coordination, control over pelvic floor muscles and helping the child to learn how to defecate properly are important specially in children who still have constipation or stool soiling after surgery and medications.

Interferential electrical stimulation is an effective modality along with pelvic floor muscle training and behavioural modifications in children with constipation post surgery.