Hirschsprung's Disease

1. Definition
   1. Enteric dysganglionosis condition
2. See Also
   1. Pediatric Constipation
3. Epidiomology
   1. Incidence: 1 in 5000 to 8,000 live births
   2. Male to female ratio: 3:1 or 4:1
4. Causes
   1. Genetic (Family History in 3-7% of cases)
      1. RET-proto-oncogene (Chromosome 10q11.2) related
      2. Associated with Multiple Endocrine Neoplasia IIa
      3. Increased risk with affected sibling
         1. Boys with sibling affected: 3-5%
         2. Girls with sibling affected: 1%
         3. Cild's sibling with entire colon affected: >12%
   2. Environmental factors
   3. Intrauterine Intestinal Ischemia or infections
5. Pathophysiology
   1. Ganglion cells absent from part or all of the colon
      1. Lack of intramural Ganglionic cells
         1. Submucosa level (Meissner's Plexus)
         2. Myenteric level (Auerbach's Plexus)
      2. Aganglionic region begins at anus, extends proximally
         1. Distance proximal to Pectinate Line exceeds 4 cm
      3. Involved distal colon fails to relax
      4. Results in progressive Functional Constipation
   2. Congenital defect at 4-12 weeks gestation
      1. Neuroblast migration interrupted
      2. Ganglion cells fail to migrate via neural crest
   3. Lack of innervation
      1. Hypertonic bowel results in functional stenosis
      2. Partial or complete colonic obstruction
      3. Proximal Intestine markedly dilated with feces, gas
6. Types
   1. Short-segment Hirschprung's Disease
      1. Limited to rectosigmoid colon
      2. More mild than long segment disease
      3. Diagnosis may be delayed into early childhood
   2. Long-segment Hirschprung's Disease
      1. Involves regions proximal to rectosigmoid
      2. In the most severe cases, may involve entire colon
7. Associated Conditions
   1. Bladder diveticulum
   2. Congenital deafness
   3. Cryptorchidism
   4. Down's Syndrome
   5. Hydrocephalus
   6. Imperforate anus
   7. Meckel's Diverticulum
   8. Neuroblastoma
   9. Primary Alveolar Hypoventilation (Ondine's Curse)
   10. Renal agenesis
   11. Ventricular Septal Defect
   12. Waardenburg's Syndrome
   13. Pheochromocytoma
   14. Meningomyelocele
8. Presentations: Age
   1. Early: Newborn
      1. No meconium in 24-48 hours of birth (90% of cases)
   2. First month of life
      1. Progressive abdominal distention
      2. Small caliber stools (pencil-thin)
      3. Infrequent, explosive Bowel Movements
      4. Failure to Thrive due to poor feeding
      5. Bilious Emesis
      6. Jaundice
   3. Two to three months of life
      1. Enterocolitis (fever, explosive bloody Diarrhea)
         1. Initial presentation in one third of patients
   4. Older Childhood
      1. Chronic progressive Constipation
      2. Failure to Thrive or malnutrition
      3. Fecal Impaction
      4. Abdominal distention
      5. Recurrent despite enemas, Laxatives, feeding changes
9. Presentation Patterns
   1. Presentation soon after birth
      1. Complete Obstruction
      2. Emesis
      3. Failure to Pass Meconium in first 24 hours (90%)
   2. Repeated Bowel Obstruction
      1. Emesis
      2. Dehydration
      3. Delayed meconium passage
   3. Persistent mild Constipation
      1. Suddenly develops obstruction
      2. Distention
      3. Emesis
   4. Diarrhea followed by obstruction
      1. Fever
      2. Enterocolitis
   5. Persistent mild Constipation
      1. Never completely obstructs
10. Signs
    1. Distended Abdomen
    2. Palpable loops of bowel
    3. Rectal exam
       1. Tight anal sphincter
       2. Rectal exam without stool in ampulla
       3. Explosive release of feces and flatus may follow exam
11. Imaging
    1. Abdominal XRay
       1. Massive colon distention with gas and feces
       2. Air-fluid levels may be present
       3. Air in bowel wall suggests enterocolitis
    2. Non-prepped Barium Enema
       1. Contraindicated if enterocolitis suspected
       2. False negative tests are common
       3. Dilated colon proximal to aganglionic region
       4. Spastic transitional segment
          1. Irregular saw-toothed outline
       5. May be best seen on lateral view
       6. Barium may be retained in proximal bowel >24 hours
12. Diagnostics
    1. Anal manometry
       1. Shows lack of internal anal sphincter relaxation
       2. Involves internal anal sphincter on rectal distention
    2. Rectal suction biopsy (>1.5 cm above Dentate Line)
       1. Absence of Meissner, Auerbach's Ganglion plexuses
       2. Marked hypertrophy of nerve trunks
13. Differential Diagnosis
    1. See Neonatal Constipation Causes
    2. See Failure to Pass Meconium
    3. Functional Constipation
       1. Onset at over age 12 months
       2. Meconium passed in first 24 hours of life
       3. Normal growth
       4. Normal rectal exam
14. Management
    1. Pre-surgery maintenance
       1. Serial rectal irrigation decreases bowel distention
    2. Surgery
       1. Mild to moderate cases (e.g. short-segment disease)
          1. Ilioanal pull-through anastomsis
       2. Severe cases (e.g. enterocolitis)
          1. Colostomy for 6 months and then ileoanal procedure
    3. Post-Surgery
       1. Maintain high Dietary Fiber
       2. Monitor for enterocolitis despite surgery
15. Complications
    1. Untreated
       1. Bowel rupture
       2. Enterocolitis (up to 50% of cases)
          1. May occur 2-10 years after surgery
    2. Post-Surgical
       1. Constipation (10%)
       2. Fecal Incontinence (1%)
16. Prognosis
    1. Early diagnosis results in best prognosis
    2. Before surgery (without recognition and treatment)
       1. Mortality: 50%
    3. After surgery
       1. Early complications: 30%
       2. Late complications: 39%
       3. Mortality: 2.4%
          1. Increased in Down's Syndrome
          2. Increased in child under age 4 months
          3. Increased if postoperative obstruction
       4. Permanent ileostomy: 0.8%
       5. Permanent colostomy: 0.5%
17. References
    1. Coran (2000) Am J Surg 180:382-7
    2. Kessman (2006) Am Fam Physician 74(8):1319-22
    3. Hussain (2002) Pediatr Clin North Am 49:27-51
    4. Worman (1995) Am Fam Physician 51(2):487-94