Doctor123.org

Congenital Megacolon (Hirschsprung Disease)

- Early infancy - Marked abdominal distention (63-91% of neonates with Hirschsprung) - Visible colonic peristalsis - Palpable fecal mass - Growth retardation (possible)

- Older infants - Failure to thrive - Empty rectum on digital examination - Palpable colon - Visible peristalsis

- Serum electrolytes - Albumin - CBC - Thyroid function - Plain abdominal radiograph - Large ovoid fecal mass mottled by small, irregular gas shadows - Fluid levels within proximal bowel loops - Diaphragm may be elevated.

- Contrast enema, water soluble (unprepped): Identification of transition zone is useful in planning definitive operative procedure (4)[B] - Dilation of sigmoid colon above narrowed distal sigmoid or rectum - Narrowed portion of colon rippled or segmented - Typical transition zone between narrowed distal colon and dilated proximal bowel - Enema may be therapeutic for other diagnoses (meconium ileus/plug, small left colon syndrome).

- Anastomotic leak in 1-10% - Cuff abscess in 5% - Perineal excoriation is common (usually improves within 2 to 3 months). - Wound infection in 4% and dehiscence in 1% - Fecal incontinence in 1-39% (3)[B] - Enuresis in 5-26% - Late mortality in 0.7-5% (3)[B] - Obstructive complications (9)[C] - Mechanical obstruction from twisting of pulled-through bowel and intra-abdominal adhesions - Secondary aganglionosis related to ischemia of pulled-through bowel - Motility disorder involving the proximal bowel (containing ganglion cells) - Internal sphincter achalasia (all children with Hirschsprung disease lack the normal rectoanal inhibitory reflex): The inability to relax the internal anal sphincter which typically improves over time.

para>Some infants have only mild or intermittent constipation with intervening bouts of diarrhea. These patients typically have aganglionosis of a short segment of distal rectum. These cases may not be diagnosed until later in infancy or childhood.

EPIDEMIOLOGY

  • Predominant age: infancy
  • Predominant sex: males > females for short segment (4:1); males > females for long segment (5:4)

Incidence

  • 1/2,000 to 5,000 births in the United States (white 91%, black 8%, Asian 0.5%)
  • 2.8/10,000 live births in Asians (1)[B]

ETIOLOGY AND PATHOPHYSIOLOGY

  • Congenital absence of Auerbach and Meissner autonomic plexuses in bowel wall (usually limited to the colon)
  • Aganglionosis results in the lack of propagation of propulsive waves of muscle contraction and absence of relaxation of the internal anal sphincter.
  • Obstruction may begin at anus and extend proximally to varying portions of the colon and small bowel.

Genetics

  • Familial inheritance: 50 times base rate
  • Associated with Down syndrome
  • Dominant mutations in the RET gene are found in 50% of familial patients with Hirschsprung disease and in 15-35% of patients with sporadic Hirschsprung disease (10q11.2 locus) (1)[B].

RISK FACTORS

  • Family history of Hirschsprung disease
  • Offspring risk if parent has short segment is 2%; if parent has long segment, risk is up to 50%.
  • Sibling risk if male affected: Female has 0.6% risk (short segment).
  • Sibling risk if female affected: Male has 18% risk (long segment).

COMMONLY ASSOCIATED CONDITIONS

  • Associated neurologic, cardiovascular, urologic, and gastrointestinal (GI) anomalies are found in 11-30% of patients (2)[C].
  • Secondary aganglionic megacolon may be a late complication of Chagas disease.
  • Down syndrome (four times expected incidence of Down syndrome in the normal population)
  • Cardiovascular defects (6%)
  • Urogenital anomalies (11%)
  • Dandy-Walker; Waardenburg; Ondine; Sipple syndromes
  • Cleft palate
  • Congenital small or large bowel atresia
  • Multiple endocrine neoplasia (MEN)-2B syndrome
  • Prematurity

DIAGNOSIS

HISTORY

  • Onset early in infancy; Newborn fails to pass meconium in 24 to 48 hours after birth (60-90% of infants with Hirschsprung disease).
  • Obstipation
  • May have diarrhea (usually intermittent)
  • Constipation (should be thoroughly investigated in any child if present since birth)Diagnosis missed in older children and adults because it is considered a neonatal disease.
  • Poor feeding habits
  • Lack of physiologic urge to defecate (older children)
  • Vomiting: bilious vomiting in 19-37% of children
  • Abdominal distension
  • 5-44% of children present with Hirschsprung-associated enterocolitis (3)[B]:Foul-smelling diarrhea, fever, and abdominal distensionMay progress to fatal toxic megacolon if untreated

PHYSICAL EXAM

  • Early infancyMarked abdominal distention (63-91% of neonates with Hirschsprung)Visible colonic peristalsisPalpable fecal massGrowth retardation (possible)
  • Older infantsFailure to thriveEmpty rectum on digital examinationPalpable colonVisible peristalsis
  • Explosive diarrhea with rectal exam
  • 5-44% of children may present with Hirschsprung-associated enterocolitis (3)[B].

DIFFERENTIAL DIAGNOSIS

  • Secondary megacolon (e.g., Chagas disease)
  • Functional/acquired megacolon
  • Functional constipation
  • Hypoganglionosis
  • Meconium plug syndrome
  • Small left colon syndrome
  • Meconium ileus
  • Neuronal intestinal dysplasia

DIAGNOSTIC TESTS & INTERPRETATION

Initial Tests (lab, imaging)

  • Serum electrolytes
  • Albumin
  • CBC
  • Thyroid function
  • Plain abdominal radiographLarge ovoid fecal mass mottled by small, irregular gas shadowsFluid levels within proximal bowel loopsDiaphragm may be elevated.
  • Contrast enema, water soluble (unprepped): Identification of transition zone is useful in planning definitive operative procedure (4)[B]Dilation of sigmoid colon above narrowed distal sigmoid or rectumNarrowed portion of colon rippled or segmentedTypical transition zone between narrowed distal colon and dilated proximal bowelEnema may be therapeutic for other diagnoses (meconium ileus/plug, small left colon syndrome).

Diagnostic Procedures/Other

  • Suction aspiration biopsy of bowel wall (2 cm above dentate line): can be done without anesthesia at bedside (absence of ganglia in wall of narrowed rectum)
  • Full-thickness biopsy may be required if suction biopsy is equivocal (most commonly needed in older infants/children who have thicker mucosa).
  • Proctosigmoidoscopy: ampulla empty of feces (not often of value without biopsy)
  • Laparoscopy: normal proximal colon dilated (not helpful without biopsy)
  • Anorectal manometry: high baseline resting pressure and absent rectoanal inhibitory reflex (3)[B]Rectosphincteric reflex may not be present until after 14 days of age.

Test Interpretation

  • Dilatation and hypertrophy of all layers proximal to involved colon (transition zone represents the transition from narrowed distal colon to dilated proximal bowel)
  • Aganglionosis of involved bowel with submucosal hypertrophied nerve bundles on biopsy
  • Calretinin and acetylcholinesterase stains may be helpful.

TREATMENT

GENERAL MEASURES

  • Treatment may be symptomatic or definitive.
  • Correct fluid and electrolyte imbalances.
  • Abdominal decompression with a nasogastric tube
  • Removal of fecal accumulation: retention enemas of 3 to 4 oz (90 to 120 mL) of mineral oil followed by repeated colonic irrigations with isotonic saline solution. Avoid use of other solutions (e.g., water, soap-sud enemas).
  • Manual disimpaction for short-segment disease may be necessary.

MEDICATION

First Line

  • Broad-spectrum IV antibiotics for patients presenting with enterocolitis (4)[A]
  • Bowel prep prior to surgery

Second Line

Metronidazole (Flagyl) for bowel preparation

SURGERY/OTHER PROCEDURES

  • Inpatient surgeryProximal colostomy and resection of aganglionic bowel is the gold standard (necessary when there is significant proximal dilatation).Definitive pull-through procedure (Duhamel, Soave, or Swenson) when dilatation has resolved (usually performed at 3 to 6 months) (2)[C].Single-stage procedure may be possible in infants.Transanal endorectal pull-through in infants if proximal bowel not too dilated (5)[C]; usually done without a protective colostomy.Transanal endorectal pull-through is associated with fewer complications and fewer episodes of enterocolitis when compared to transabdominal pull-through procedures (6,7)[A]:Laparoscopic technique may be used alone or combined with transanal endorectal pull-through.
  • Confirmation of normal ganglion cells mandatory at colostomy and proximal resection sites prior to anastomosis
  • Total-colon Hirschsprung disease may require other procedures, including Martin modification of Duhamel pull-through (5,8)[C]:Cecal patches may be used to facilitate water absorption in pulled-through small bowel.
  • Total-bowel Hirschsprung disease (68 reported cases in world literature through 2009) (9)[B]Family history of Hirschsprung disease in 14.7%, RET gene mutation was identified in 71.4%, associated anomalies were found in 20.6%; 66.2% died before age 8 yearsUltimately requires small bowel transplantation.Long (30 to 40 cm) myomectomy of proximal bowel and creation of proximal small bowel stoma (at 30 to 40 cm from ligament of Treitz) may allow small-volume feeding in some infants.

INPATIENT CONSIDERATIONS

Admission Criteria/Initial Stabilization

Early workup (ambulatory or in hospital, depending on the patient's condition)

ONGOING CARE

FOLLOW-UP RECOMMENDATIONS

Patient Monitoring

  • Postsurgical monitoring for fluid/electrolyte balance, protein-calorie nutrition and growth
  • Long-term monitoring for continence and constipation

DIET

  • Diet does not control obstipation.
  • Postoperative diet: standard for age

PATIENT EDUCATION

  • After surgery, instruct parents to detect and report dehydration, decreased urinary output, sunken eyes, poor skin turgor, vomiting, or fever.
  • Parental bonding through maximal participation in their child's care, including colostomy care
  • Request enterostomal therapist to teach family appropriate colostomy care.
  • Daily anorectal dilations are frequently required following Soave or transanal endorectal pull-through procedures to prevent anastomotic stricture:May be required for several months

PROGNOSIS

  • FavorableMortality decreased over last 25 years, now estimated at ≤3% (2)[C]
  • Requires long-term follow-up.
  • Aggressive management of suspected enterocolitis:Rectal irrigationIV antibioticsNasogastric decompression

COMPLICATIONS

  • Toxic enterocolitis, possibly fatalThe reported mortality from enterocolitis has decreased to <1% over the last 20 years (10)[B].Enterocolitis may occur before or after definitive pull-through:5-42% of postoperative patientsThe rate of enterocolitis may be less after transanal pull-through compared with other procedures (10)[B].Enterocolitis may be rapidly progressive.Diagnostic features are abdominal distension, lethargy, bilious emesis, and diarrhea.Treated with nasogastric decompression, IV hydration, IV antibiotics, and colonic washouts
  • Bleeding and/or perforation
  • Anal stenosis at anastomotic site (0-35%)Stricture is associated with higher risk of postoperative enterocolitis (3)[B].
  • Anastomotic leak in 1-10%
  • Cuff abscess in 5%
  • Perineal excoriation is common (usually improves within 2 to 3 months).
  • Wound infection in 4% and dehiscence in 1%
  • Fecal incontinence in 1-39% (3)[B]
  • Enuresis in 5-26%
  • Late mortality in 0.7-5% (3)[B]
  • Obstructive complications (9)[C]Mechanical obstruction from twisting of pulled-through bowel and intra-abdominal adhesionsSecondary aganglionosis related to ischemia of pulled-through bowelMotility disorder involving the proximal bowel (containing ganglion cells)Internal sphincter achalasia (all children with Hirschsprung disease lack the normal rectoanal inhibitory reflex): The inability to relax the internal anal sphincter which typically improves over time.

REFERENCES

11 Tam PK, Garcia-Barcel ³ M. Genetic basis of Hirschsprung's disease. Pediatr Surg Int. 2009;25(7):543-558.22 Suita S, Taguchi T, Ieiri S, et al. Hirschsprung's disease in Japan: analysis of 3852 patients based on a nationwide survey in 30 years. J Pediatr Surg. 2005;40(1):197-201; discussion 201-202.33 Haricharan RN, Georgeson KE. Hirschsprung disease. Semin Pediatr Surg. 2008;17(4):266-275.44 Langer JC. Hirschsprung disease. Curr Opin Pediatr. 2013;25(3):368-374.55 Wildhaber BE, Teitelbaum DH, Coran AG. Total colonic Hirschsprung's disease: a 28-year experience. J Pediatr Surg. 2005;40(1):203-206; discussion 206-207.66 Kim AC, Langer JC, Pastor AC, et al. Endorectal pull-through for Hirschsprung's disease-a multicenter, long-term comparison of results: transanal vs transabdominal approach. J Pediatr Surg. 2010;45(6):1213-1220.77 Gosemann JH, Friedmacher F, Ure B, et al. Open versus transanal pull-through for Hirschsprung disease: a systematic review of long-term outcome. Eur J Pediatr Surg. 2013;23(2):94-102.88 Laughlin DM, Friedmacher F, Puri P. Total colonic aganglionosis: a systematic review and meta-analysis of long-term clinical outcome. Pediatr Surg Int. 2012;28(8):773-779.99 Ruttenstock E, Puri P. A meta-analysis of clinical outcome in patients with total intestinal aganglionosis. Pediatr Surg Int. 2009;25(10):833-839.1010 Ruttenstock E, Puri P. Systematic review and meta-analysis of enterocolitis after one-stage transanal pull-through procedure for Hirschsprung's disease. Pediatr Surg Int. 2010;26(11):1101-1105.

ADDITIONAL READING

De La Torre L, Langer JC. Transanal endorectal pull-through for Hirschsprung disease: technique, controversies, pearls, pitfalls, and an organized approach to the management of postoperative obstructive symptoms. Semin Pediatr Surg. 2010;19(2):96-106.

SEE ALSO

Constipation

CODES

ICD10

Q43.1 Hirschsprungs disease

ICD9

751.3 Hirschsprungs disease and other congenital functional disorders of colon

SNOMED

  • Hirschsprungs disease (disorder)
  • Congenital dilatation of colon (disorder)
  • Long segment Hirschsprung's disease (disorder)
  • Short segment Hirschsprung's disease (disorder)

CLINICAL PEARLS

  • All infants with primary constipation must be evaluated for Hirschsprung disease.
  • Early diagnosis helps prevent toxic enterocolitis.
  • An unprepped barium enema followed by a suction rectal biopsy confirms the diagnosis of Hirschsprung disease.