hirschsprung disease

7/21/2019 Hirschsprung Disease

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Hirschsprung Disease

• Intestinal abnormality of aganglionosis of the distal bowel beginning at the anus and extending proximately for avariable distance, causing partial or complete intestinal obstruction, difficulty in passing stools, and in some casesenterocolitis

• Also known as congenital megacolon

• First reported by Harald Hirschsprung in 1888

• resent as complete obstruction, delayed passage of meconium, !chronic constipation," or enterocolitis

Incidence• #ost common cause of lower intestinal obstruction in neonates$ 1 in %,&&& births

• Familial incidence in total colonic aganglionosis$ '%( of cases, rectosigmoid involved) 1*(, descending coloninvolved) 8(, colon involved) +(, small bowel affected

BASICS-EPIDEMIOLOGY-Prevalence• verall rate of male-female patients is ./8$1) in long0segment disease, it is ./8$1, and in total colonic aganglionosis,

it is ./.$1/

• yndromic and nonsyndromic Hirschsprung disease$ In the former there are other congenital anomalies 2+&( ofcases3, whereas in the latter it occurs as an isolated trait/

RISK FACTORS

Genetics• ossible gene loci at chromosomes +p.1, 1&411, and 1541.

• Associated with mutations in the 67 proto0oncogene

• 9%( of patients with Hirschsprung disease have mutations in the endothelin signaling pathway/

PATHOPHYSIOLOGY• :asic histologic finding is the absence of #eissner and Auerbach plexuses and hypertrophied nerve bundles

between the circular and the longitudinal muscles and in the submucosa/

• ;efect is considered as a failure of caudal migration of the neural crest cells/

BASICS-ASSOCIATED-CO DITIO S• In +( of the patients, there has been an association with ;own syndrome, cardiac anomalies, and coexistent

multiple neuroblastomas/

• #ore recently there have been case reports of neurologic disorders associated in children with Hirschsprungdisease/

• #ay be familial and associated with disorders of the urogenital tract, cardiovascular defects, other <I systemdisorders, cleft palate, and extremity defects/

• Another study reveals upper gut dysmotility in patients with Hirschsprung disease and its allied disorders in adults/

Diagnosis



SIG S A D SYMPTOMS

Hist!r"• 8&( of patients present in the neonatal period/

• ypical symptoms$ Failure to pass meconium by *8 hours of life) delayed passage of meconium after .* hours oflife) history of constipation) history of chronic laxative use, abdominal distention, bilious vomiting, diarrhea in

..( of patients• =eonates usually have normal weight, but growth retardation may occur when the disease is severe/

• >hildren with Hirschsprung disease usually have small0volume and small0diameter stools/ ome may haveoverflow diarrhea as well/

P#"sical E$a%• n rectal examination, the sphincter tone is usually normal or increased/ 6emoval of the finger may be followed by

explosive diarrhea) transition ?one is usually not felt in infants @. months of age/

• In most instances, especially in older children, the rectum is empty/

• atients may be anemic owing to chronic blood loss from the large bowel secondary to infection/

TESTS

LABORATORY

>:>$ Anemia, leukocytosis in the presence of enterocolitis

IMAGI G• lain film of abdomen$

1/ #ay show distended loops of colon

./ mall bowel air is usually present in the bowel proximal to the obstruction/

+/ ;iffuse intestinal pneumatosis has been reported as a rare presentation/

• :arium enema$

1/ seful but not diagnostic

./ ransition ?one is a funnel0shaped area of intestine with normal distal area and dilated proximal area/

+/ 6eveals large intestinal mucosal pattern, prominently thickened folds, and irregular margins secondary toulceration

*/ ignificant delay in excretion of barium should also raise oneBs suspicion for Hirschsprung disease/

DIAG OSTIC PROCED&RES• Anorectal manometry$ ;iagnostic, but usually reserved for those cases causing diagnostic difficulties, as in the

ultrashort segment disease/

• uction biopsy$

1/ hould be done 9.C* cm from the anal verge depending on the age of the patient

./ :iopsies must have ade4uate submucosa to demonstrate neurofibrils detected using acetylcholinesterase as



a stain/

+/ Dith the absence of ganglion cells, biopsy is diagnostic/

*/ If the suction biopsies are not conclusive, a full0thickness biopsy is mandatory/

PATHOLOGICAL FI DI GS•

Aganglionic segment• Eone of hypoganglionosis proximal to the aganglionic segment

• Incomplete maturation of enteric nerve plexus

• Hypertrophy of nonmyelinated nerve fibers within bowel wall

DIFFERE TIAL DIAG OSIS• #echanical obstruction

• #econium ileus

• #econium plug syndrome

• =eonatal small left colon syndrome

• #alrotation with volvulus

• Intestinal atresia

• Intussusception

• =ecroti?ing enterocolitis

• Functional obstruction

• Intestinal neuronal dysplasia

• epsis

• #etabolic disorders 2e/g/, uremia, hypothyroidism3

• ;isorders of intrinsic enteric nerves 2diabetes or dysautonomia3

• ;isorders of smooth muscle function

• 7lectrolyte disturbances

• >hronic constipation

CLI ICAL'

7arly recognition is of utmost importance in reducing the morbidity and mortality of Hirschsprung disease/

Treatment

GE ERAL MEAS&RES

tabili?ing treatment$

• Fluid resuscitation

• =asogastric decompression



• :road0spectrum antibiotics

• aline enemas for decompression

MEDICATIO S• 1st ine$

1/ For constipation$ 6hubarb, prune or pear Guice, bran./ For diarrhea$ :ananas, carrots, blueberries

• .nd ine$

1/ For constipation$ enna extract

./ For diarrhea$ >holestyramine, loperamide 2must make sure diarrhea is not due to enterocolitis3

S&RGERY• Initial operation$

1/ ;efunctionali?ing colostomy or ileostomy for total colonic aganglionosis or if child presents withobstruction not relieved by rectal irrigations

• erformed to avoid the ha?ards of enterocolitis

• If the child has already developed enterocolitis, colostomy may be deferred until the generalcondition improves$

• ;efinitive surgery$

1/ erformed months to 1 year after the initial colostomy

./ #ay be performed as initial procedure in stable, nonobstructed child

• he various surgical procedures performed are$

1/ 7ndorectal pull0through$

• Didely used

• :asic principle is to strip the aganglionic rectum of its mucosa and then to bring normallyinnervated colon through the residual rectal muscular cuff, thereby bypassing the abnormal bowelfrom within/

• Advantages$ phincter function is preserved and minimal danger of inGury to pelvis

./ 6etrorectal transanal pull0through 2;uhamel procedure3$

• he normally innervated bowel is brought behind the abnormally innervated rectum 91C. cmabove the pectinate line, and an end0to0side anastomosis is performed/

• rocedure creates a neorectum with the anterior half having normal sensory receptors and aposterior 1-. with normal propulsion/

• Advantages$ 6educes pelvic dissection to a minimum and retains the sensory pathway of rectalreflexes

• ;isadvantages$ Incontinence if anastomosis is too low and obstructive symptoms if anastomosisis too high or if the aganglionic segment is too long



+/ ther procedures include the oave 2endorectal pull0through3/

*/ In total colonic aganglionosis, the modified ester #artin techni4ue may be performed$ Involves theanastomosis of the cecum and ascending colon as an onlay patch graft in the more distal normal smallbowel, which is then pulled through the amputated rectum, which has been stripped of its mucosa, and aprimary anastomosis is performed/

%/ aparoscopy0assisted abdominoperineal pull0through has shown good intermediate results, and the morerecent transanal pull0through is promising/ ong0term results are awaited/

CLI ICAL'• >linicians must have HI<H suspicion for enterocolitis both before and after definitive pull0through/

• Fecal incontinence could occur after surgery/

Follow-up Recommendations : #ost children are followed on a regular basis for the 1st decade after surgery/

POSSIBLE COMPLICATIO S• 7arly 2@* weeks postoperation, usually related to technical issues3$

1/ Anastomotic leaks

./ >uff abscesses and retraction of pull0through segment

+/ ;isturbances of micturition

*/ Dound infections, intra0abdominal adhesions

• ate$

1/ >hronic constipation

./ ong0term voiding dysfunction

+/ exual dysfunction due to dissection around pelvic nerve plexus

*/ 7nterocolitis

• 7nterocolitis is the most important complication$

1/ econdary to obstruction causing an increase in intraluminal pressure and decreased intramural capillaryblood flow

./ Affects the protective mucosal barrier, enabling fecal breakdown products, bacteria, and toxins to enter thebloodstream

+/ sually presents with fever, diarrhea, and fre4uent, bloody, bilious vomiting

*/ >an occur both before and after definitive pull0through

%/ >linicians must have HI<H suspicion) can be rapidly progressive and FAA

• $ Dill the bowel movements be normal after surgeryJ

• A$ tudies have shown that 8+( of children have + or fewer stools per day at a mean follow0up of */1 K ./% years/

• $ Are laxatives re4uired after surgeryJ

• A$ In 9.&( of children, some sort of laxative therapy or rectal irrigation may be re4uired/

hirschsprung disease

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