hirchsprang's disease
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• A.k,a Congenital aganglionic megacolon
• Discovered by Harald Hirchsprang (1886(
• Is a condition that affects GIT and usually causes problems with passing stool.
• Present when a baby is born (congenital( and results from missing nerve cells in the muscles of part or all of the baby’s colon.
• most common cause of lower intestinal obstruction in neonates.
• Familial tendency
• Risk factors;
- +ve family hx,
- being male,
- having other inherited conditions (heart problems, Down sydrome(
Introduction
Incidence
• 1\5000 live birth newborn
• 70-80% is boys.
• (M / F. 4: 1 (
• Total colonic aganglionosis, 35% girls
• 3-5% have Down’s sydrome
• Less common in blacks.
• >95% cases are full term babies
• Prematurity is reported in as many as 10% of those children with HD
• Familial tendency (Dominant pattern of inheritance(
EMBRIYOLOGY
During normal fetal development cells from neural crest migrate into the large intestine to form the network of nerves called Auerbach’s plexus (Muscularis externa( and Meissner’s plexus ( submucosa(
-Occurs in the end of first trimester-Lack of these nerves causes failure of
relaxation of the involved part of the colon. -Also supplied by sympathetic nerves, and
intrinsic component (enteric nervous system(
HD, due to failure of neural crest cells to migrate caudallyAganglionosis begins at anorectal line
(internal anal sphincter(
80% extend only up to rectosigmoid junction(Short segment(
10% extend proximal to splenic flexure10% involves the entire colon and part of small bowel
Rarely involves entire gastrointestinal tract
Types
1. Congenital : Commonest
2. Acquired : Degeneration of the ganglions may occur due to:
-Vascular causes like after pullthrough procedure due to ischemia & tension.
- Non vascular causes like Trypanosoma (chaga's disease(. Vit B1 def. Chronic infection ( TB.(.
Causes
-No clear cause identified -Due to mutations in one of several genes
RET proto-oncogene locus10q11.2 (most common( EDNRB, locus 13q22 >endothelin receptor type B
EDN3, locus 20q13.2-q13.3 >endothelin 3
RET gene -Provides instructions for producing a protein that is involved in
signalling within cells,essential for the normal development of several kinds of nerve cells (cells of the neural crest(
-Ass with thyroid cancer and neuroblastomaEDNRB, EDN3 > coded proteins helps to connect the nerve cells to to the digestive tract
Other: Nueregulin 3(NRG3( > formation of enteric nervous sytem.
PATHOPHYSIOLOGY
• The gross pathologic feature of HD is a dilated proximal intestine with gradual or abrupt transition
to normal calibrated distal intestine . .
• The colon proximal to the aganglionic segment, in an effort to overcome the partial obstruction,
becomes distended and its wall markedly thickened because of muscle hypertrophy
• The degree of hypertrophy and dilatation depends upon the duration and degree of obstruction
and thus, indirectly to the age of the patient.
• TZ is typically funnel like or cone shaped
ASSOCIATED ANOMALIES
HD is usually a solitary anomaly in a full term, otherwise healthy infant
Associated anomalies do occur in nearly 20% of cases • urogenital system (11%)• cardiovascular system (6%) • gastrointestinal system (6%), • with 8% having various other malformations
Ass sydromes:
Waardenburg-Shah sydrome
Trisomy 21 occurs in approximately 5% of cases
Mowat-Wilson sydrome,
Goldberg-Shpritez megacolon sydrome, and
Congenital central hypoventilation sydrome.
MEN2 (Multiple endocrine neoplasia)
Waardeberg syndrome
An inherited auotosomal dominant disorder
-hearing loss
-Pigmented anomalies affecting the eyes, hair, skin and various defects of neural
crest derived tissues
Four variants:
Types 1-4
-Type 1: common cause of genetic deafness
-Type 4:( ass with Hirchsprung’s disease)
Signs n symptoms
In newborns -Failure to pass muconium-Abd distension-Vomiting (bilious)-Constipation or gas-Diarrhoea
In older children-Chronic constipation-abd distension-failure to gain weight (growth retardation)
COMPLICATIONS Neonatal Intestinal obstruction -bilious vomiting, -abdominal distension -failure to pass muconium Recurrent Enterocolitis mainly in the 1st three months of life. -fever, -lethargy, -anorexia, -vomiting, -abd distenon and -diarrhoea Tx: antibiotics, antpyretics, fluids Spontanous perforation occurs in 3%, specially if long segment aganglionosis.
Chronic constipation Growth retardation Volvulus.
DiagnosisHistory Failure to pass meconium, painless abdominal distension & constipation
Physical examinations Distended abdomen Multiple fecal masses on abdominal examination On DRE:
• Anal sphincter is hypertonic• Rectal ampulla is typically empty.• Hard fecal mass.• Gash of air apon withdrawal of finger
Investigations
Radiology 1. Plain x-rays of the abdomen :Erect & supine2. Contrast enema– contrast enema should be done without preparation
of bowel– Shows narrow distal segment,– funnel-shaped dilatation at level of transition zone
with marked dilatation of the proximal colon.24-hrs delayed films (child with psychogenic stool holding)
Electromanometry .– The classic finding is the absence of the recto anal inhibitory
reflex when the rectum is distended. (Lack of internal anal sphincter relaxation in response to rectal
stretch), balooning– not useful in neonate– excellent screening tool in infant & children
Rectal biopsy :– Definitive diagnostic test – demonstrates absence of ganglion cells, – nerve hypertrophy and – stains indicating increased acetylcholinesterase activity.
suction mucosal biopsy (at different levels ), can be done without anesthesiafull thickness biopsy is done under general anesthesia.
UltraSonography: for associated anomalies.
Management :
• Acute I.O. ,– NGT , – NPO– IVF ,– Antibiotics ,– Rectal tube irrigations .– The initial treatment requires performing a colostomy. ( multiple seromuscular biopsies)
Note: The colostomy is placed above the transition zone. – Placement in an area of aganglionosis will lead to persistent obstruction– Definitive treatment will be planned.
• Chronic constipation :– Laxative – Saline enema.– Work up to establish the diagnosis– Definitive treatment will be planned
Definitive procedures: By the age of 6-12 months; 9kg or more), a formal pull-through procedure is done
1. Open surgery :There are many surgical options for Pull-through operation. All aiming at resection of aganglionic segment They give excellent result in 90%.
a.swenson.b.soave. c.Rehbein.d.Duhamel.e. Boley's.
Swenson ProcedureSharp extrarectal dissection down to 2 cm above the anal canal
Aganglionic colonic segment resected
End-to-end anastamosis of normal proximal colon to anal canal
Completely removes defective aganglionic colon
Duhamel Procedure Posterior portion of defective colon segment resected
Side to side anastamosis to left over portion of rectum
Constipation a major problem d/t remaining aganglionic tissue
Simpler operation, less dissection
Soave ProcedureCircumferential cut through muscular coat of colon at peritoneal reflection
Mucosa separated from the muscular coat down to the anal canal
Proximal normal colon is pulled through retained muscular sleeve
Telescoping anastamosis of normal colon to anal canal
Advantage: rectal intramural dissection ensures no damage to pelvic neural structures
Higher rate enterocolitis, diarrhoea, often requires repeated dilations
2. LAPAROSCOPY . Transanal endorectal pullthrough
-Excised aganglionic tissues removed through anal canal
-no abdominal incision
-Better results in terms of pain, return of bowel function, shortens hospital stay
-Similar incidence of leaks, pelvic abscesses, enterocolitis.
One vs Two Stage procedure
Historically,Two stage procedure performed: preliminary colostomy, then completion pull through
-Delicate muscular sphincters of newborn may be injured
1980s, 1 stage procedures became more popular
Comparison by complications
Early complications: No difference in incidence of anastomotic leak, pelvic infection, prolonged ileus, wound infection, wound dehiscence
Late complications: No difference in incidence of anastomonic stricture, late obstruction, constipation, incontinence, urgency
Postoperative enterocolitis higher in 1 stage (42% vs 22%(
COMPLICATIONS
1. anastomotic leak.2. stricture .3. retraction of the colon.4. fecal incontinence (soiling/encopresis/paradoxical
diarrhoea (.5. persistant constipation.
NOTE: -Afebrile Dirrhoea soon after pullthrough is
expected -Fluid and observation, Avoid antemetics
Feature Functional Constipation Hirschsprung’s Disease
Onset 2-3 years At birth
Delayed passage of meconium Rare Common
Obstructive symptoms Rare Common
Withholding behavior Common Rare
Fear of defecation Common Rare
Fear of incontinence Common Rare
Stool size Very large Small, ribbon-like
Poor growth Rare Common
Enterocolitis Never Possible
Rectal ampulla Enlarged Narrowed
Stool in ampulla Common Rare
Barium enema Lg amount of stools,no transitional zone
Transitional zone, delayedemptying
Anorectal manometry Normal Absent rectosphincteric refl ex
Rectal biopsy Normal No ganglion cells, nerve hypertrophy and increase acetylcholinesterase activity
Distinguishing features between childhood functionalconstipation and Hirschsprung’s disease
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