Definition

Congenital develoental disorder characterised by the absence of ganglion cells in myenteric(Auerbach’s)plexus and aubmucosal Meissner’s plexus.

Epidemiology

Occurs in 1 in 5000 childbirths, more common in males and m:f ratio is 4:1.

Etiology

Family history of HIrschsprungs, 3-5 percent of HIrschsprungs disease are associated with downs disease, Abnormal locus in Chromosome 10, RET oncogene, MEN 2 are the etiological factors

Pathophysiology

Hirschsprungs disease is characterised by muscular spasm of the distal colon and rectum upto internal anal sphincter, leading to functional intestinal obstruction.Abnormal bowel appears distally and appears contracted whereas the proximal normal bowel appears dilated. This usually begins at anorectal line and rrctosigmoid is affected in 80% splenic flexure in 17% and entire colon is affected in 8%

According to length of bowel involved HIrschsprungs is divided into 4/types
1.Ultra short segment- Analcanal and terminal rectum
2.Short segment- Anal canal and rectum
3.Long sefment- Anal canal and up to splenic flexure
4.Total xolonic- Involving entire colon

Clinical features

More than 90% infants present with abdominal distsion and bilious vomiting along with failure to pass meconium in first 24 hours after birth.Diarrhoea may develop due to enterocolitis.
MISSED HIRSCHSPRUNG’S – In some infants Hirschsprung may be missed in infancy and may be diagnosed in childhood and early adulthood.It is characterised by poor feeding,abdominal distension, constipation and passage of goat pellet like stools. In young adults it presents as intestinal obstruction.

Complications
Intestinal obstruction
Hematochezia
Perforation
Peritonitis
Sepsis

Diagnosis

Barium enema

Characterised by

1.Rectum is normally more dilated compared to sigmoid, but in HIrschsprungs disease, sigmoid has increased calibre compared to rectum.

2.Failure to evacuate instilled contrast after 24 hours

Manometry

Failure of internal sphincter to relax when rectum is distended with balloon is the characteristic finding

Rectal biopsy

This is the gold standard test in HIrschsprungs disease
In infants rectal biopsy is taken using special suction rectal biopsy instrument. Biopsy should be taken from 2 cm above dentate line. In older children full thickness biopsy is taken under GA

Histopathologic criteria

Absent ganglia
Hypertrophied nerve trunks
Robust immunostaining for acetyclcholinesterase
Loss of calretinin staining

Treatment

Initial treatment is diversion colostomy which can be by loop or end colostomy done at ganglionic segment
Nutritional supplementation incliding and elecrolyte imbalance correction should be done
Followed by definitive procedures like
1.Swenson procedure – Resection of aganglionic bowel up to internal sphincter followed by colonial anastomosis

2.Modified Duhamel’s procedure – Resection of bowel leaving a distal rectal stump, followed by colon pill through posterior to rectal stump and stapler anastomosis between rectum and colon leaving a posteriror wall formed by ganglionic colon.

3.Suave procedure – Endorectal mucosal resection followed by colon pull through and colo anal anastomosis

Post operative complications

Constipation
Soiling
Incontinence
Enterocolitis
Fecal fistulas