Hirschsprung disease

Normal or contracted REF: Sabiston Textbook of Surgery, 18th ed chapter 71

Hirschsprung’s disease occurs in 1 out of every 5000 live births and is characterized pathologically by absent ganglion cells in the myenteric (Auerbach’s) and submucosal (Meissner’s) plexus. This neurogenic abnormality is associated with muscular spasm of the distal colon and internal anal sphincter resulting in a functional obstruction. Hence, the abnormal bowel is the contracted, distal segment, whereas the normal bowel is the proximal, dilated portion. The area between the dilated and contracted segments is referred to as the transition zone.

Failure of migration of neural crest cells from cranial to caudal direction [Ref Schwartz’s Surgery 9/e p1436 (8/e p1496)]

The cause of Hirschsprung’s disease remains incompletely understood, although current thinking suggests that the disease results from a defect in the migration of neural crest cells, which are the embryonic precursors of the intestinal ganglion cell. Under normal conditions, the neural crest cells migrate into the intestine from cephalad to caudad. The process is completed by the twelfth week of gestation, but the migration from midtransverse colon to anus takes 4 weeks. During this latter period, the fetus is most vulnerable to defects in migration of neural crest cells. This may explain why most cases of aganglionosis involve the rectum and rectosigmoid. The length of the aganglionic segment of bowel is therefore determined by the most distal region that the migrating neural crest cells reach. In rare instances, total colonic aganglionosis may occur.

Hirschprungs ds or Agangliottic megacolon

• is a congenital disorder d/t absence of ganglion cells in the neural plexus ie both myentric (Aurebach’s) and submucosal (Meissner’s) plexus of the intestinal wall.
• There is accompanying hypertrophy of the nerve trunks.
• MC site is rectosigmoid colon.* (or Rectum, more specificaly)*
• The Clinical picture varies from acute intestinal obstruction in neonates to chronic constipation in later life.
• One imp _.feature which distinguishes Hirschprungs disease _.from other types of constipation is that fecal soiling is not a feature of HD.
• M: F ratio is 4: 1
• Diagnosis
• Rectal biopsy ?

– Diagnosis can be confirmed by full thickness rectal biopsy and demonstration of aganglionosis and hypertrophied nerve fibres.

• Anorectal manometry ?

– is a useful screening test in constipated young child or adult who is otherwise fit.

• Treatment of choice

– is pull-through procedure in which normally innervated colon is anastomosed to the distal rectum just above the internal sphincter, thus bypassing the contracted aganglionic segment and restoring normal defecation. Note that:

• Similar loss of ganglion cells is seen in Achalasia of oesophagus.
• Achalasia is due to loss of ganglion cells in Myenteric or Auerbachs plexus*.
• Achalasia differs from the Hirschsprung ds of the colon in that the dilated esophagus contains no ganglion cells (or few cells) but the dilated colon contains normal ganglion cells.

Fasanella – servat procedure is done in cases of mild congeital ptosis, mild ptosis associated with horner’s syndrome and selected cases of mild acquired involutional ptosis, in which the upper lid is elevated by removing a block of tissue from the underside of the lid.

This tissue includes the tarsus, conjunctiva, and Müller muscle.

Note:
Treatment of hirschsprung’s disease:

• Colostomy- prompt colostomy should be performed in neonate with the disease.
• “Definitive operation is postponed till the child become at least 1 year of age and normal weight. It includes- Swenson’s operation, Duhamel’s operation, Soave’s operation, colonic anastomosis etc”

Ref: Love & bailey 25/e, page 86-87 ; S. Dass Textbook of Surgery 5/e, page 1035-36 ; Comprehensive Opthalmology by AK Khurana, 4/e, page 358 ; Opthalmic Surgical Procedures by Petre Hersh, 2/e, page 281

Diagnosis Of Hirschsprung’s Disease

• Rectal manometry and rectal suction biopsy are the easiest and most reliable indicators of HD.
• Rectal suction biopsies are the procedure of choice and should be performed no closer than 2 cm to the dentate line to avoid the normal area of hypoganglionosis at the anal verge. Anorectal manometry measure the pressure of the internal anal sphincter while a balloon is distended in the rectum. In patient with HD, pressure fails to drop or there is a paradoxical rise in pressure with rectal distension.
• Barium enema examination should be done in unprepared bowel as washout may minimise the dilation of the gut above the obstruction. It is always essential that both AP and lateral view should be taken as narrow short segment may be overlapped by dilated proximal colon in one of the view’s.

Ref: Love & bailey 25/e, page 86-87 ; Nelson 18/e, page 1565-67 ; S. Dass Textbook of Surgery 5/e, page 1035-36

Constipation in Hirschsprung’s disease is organic not functional. 

Genetic studies have identified mutations in different genes contributing to the development of Hirschsprung disease.

Small number of  patients with MEN 2A have associated Hirschsprung disease. In MEN2A/Hirschsprung disease variant aganglioneuromatosis may be found throughout the colon or in smaller segments. Characteristic features of MEN 2A are medullary carcinoma of thyroid,  pheochromocytoma and parathyroid adenoma.

Ref: Harrisons Internal Medicine, 16th Edition, Chapter 295, Pages 2231-34.

Ans. is ‘a’ i.e., Distal to dilated segment

Congenital aganglionic megcolon (Hirschsprung disease)

o Hirshsprung disease a congenital disorder characterized by aganglionosis of a portion of the intestinal tract.

o An intestinal segment lacks both Meissner submucosal and Auerbach myenteric plexuses. This leads to func­tional obstruction and intestinal dilation Proximal to the affected segment.

o Histological findings are :-

(i)      Absence of ganglion cells and ganglia in the muscle wall and submucosa of the affected segment.

(ii)       Thickening and hypertrophy of nerve trunk.

o Rectum is always affected with involvement of more proximal colon to variable extent –> most cases involve the rectum and sigmoid only.

o Proximal to the aganglionic segment, the colon undergoes progressive dilation and hypertrophy. o With time, the proximal innervated colon may become massively distended –> megacolon.

Ans. is ‘b’ i.e., Loss of intrinsic enteric plexuses

Pathogenesis of Hirchsprung disease

o The entric neuronal plexuses develops from neural crest cells, which migrate into the bowel wall during develop­ment, mostly in a cephalad to caudad direction.

o Hirschsprung disease results when the migration of neural crest cells arrests at some point before reaching the anus —> inappropriate premature death.

o This produces an intestinal segment that lacks both meissner submucosal and aurebach myenteric plexus.

o Loss of enteric neural coordination leads to functional obstruction and intestinal dilation proximal to the affected segment.

Ans. is ‘c’ i.e., Manometry excludes the diagnosis

o Anorectal manometry is a useful screening procedure for the diagnosis of Hirschsprung’s disease. A normal response in course of manometric evaluation precludes diagnosis of Hirschsprung’s disease. o However the confirmation of diagnosis in case of Hirschsprung’s disease is done by rectal biopsy.

Ans. is ‘a’ i.e., Distal to dilated segment

Congenital aganglionic megacolon (Hirschsprung disease)

• Hirschsprung disease is a congenital disorder characterized by aganglionosis of a portion of the intestinal tract.
• An intestinal segment lacks both Meissner submucosal and Auerbach myenteric plexuses. This loss of enteric neural coordination leads to functional obstruction and intestinal dilation proximal to the affected segment.
• Histological findings are ‑

i) Absence of ganglion cells and ganglia in the muscle wall and submucosa of the affected segment. Thickening and hypertrophy of nerve trunk.

ii) Rectum is always affected with involvement of more proximal colon to variable extent —> most cases involve the rectum and sigmoid only.

o Proximal to the aganglionic segment, the colon undergoes progressive dilation and hypertrophy. o With time, the proximal innervated colon may become massively distended —> megacolon.

Ans. is ‘c’ i.e., Manometry excludes the diagnosis

o Anorectal manometry is a useful screening procedure for the diagnosis of Hirschsprung’s disease. A normal response in course of manometric evaluation precludes diagnosis of Hirschsprung s disease.

o However the confirmation of diagnosis in case of Hirschsprung’s disease is done by rectal biopsy.

Ans. is ‘a’ i.e., Rectal biopsy

o Rectal suction biopsy is procedure of choice.

Ans is ‘a’ ie Autosomal dominant

• Hirschprungs ds or Aganglionic megacolon or Congenital megacolon
• is a congenital disorder d/t absence of ganglion cells in the neural plexus ie both myentric (Aurebach’s) and submucosal (Meissner’s) plexus of the intestinal wall.
• There is accompanying hypertrophy of the nerve trunks.
• MC site is rectosigmoid colon.* (or Rectum, more specificaly)*
• The Clinical picture varies from acute intestinal obstruction in neonates to chronic constipation in later life.
• One imp feature which distinguishes Hirschprungs disease from other types of constipation is that fecal soiling is not a feature of HD.
• M: F ratio is 4: I
• Diagnosis:
• Barium enema: The initial diagnostic step in a newborn with radiographic evidence of a distal bowel obstruction is a barium enema. In a normal barium enema study, the rectum is wider than the sigmoid colon. In patients with Hirschsprung’s disease, this relationship is reversed.
• Rectal biopsy ‑

– Diagnosis can be confirmed by full thickness rectal biopsy. Rectal biopsy is the gold standard for the diagnosis of Hirschsprung’s disease.

The histopathologic features of Hirschsprung’s disease are:

Absent ganglia,

hypertrophied nerve trunks, and

increased acetylcholinesterase staining

• Anorectal manometry ‑

–       is a useful screening test in constipated young child or adult who is otherwise fit.

• Treatment of choice

– ‘ is pull-through procedure in which normally innervated colon is anastomosed to the distal rectum just above the internal sphincter, thus bypassing the contracted aganglionic segment and restoring normal defecation.

• Option a

Most of the cases are sporadic, Familial cases also occur but their inheritance pattern is not clear.

Ans is ‘c’ i.e. Failure of migration of neural crest cells from cranial to caudal direction 

The cause of Hirschsprung’s disease remains incompletely understood, although current thinking suggests that the disease results from a defect in the migration of neural crest cells, which are the embryonic precursors of the intestinal ganglion cell. Under normal conditions, the neural crest cells migrate into the intestine from cephalad to caudad. The process is completed by the twelfth week of gestation, but the migration from midtransverse colon to anus takes 4 weeks. During this latter period, the fetus is most vulnerable to defects in migration of neural crest cells. This may explain why most cases of aganglionosis involve the rectum and rectosigmoid. The length of the aganglionic segment of bowel is therefore determined by the most distal region that the migrating neural crest cells reach. In rare instances, total colonic aganglionosis may occur.

Answer ‘a’ i.e. Pathology of myentric plexus of Aurbach : ‘c’ i.e. May involve small intestine rarely Small intestine may be involved rarely (-5%) 

Ans. is ‘b’ i.e., Is at least 8 kg. in weight and thriving 

10 kg is given in both Bailey & Schwartz

Ans. is ‘a’ i.e., It is initially treated by colostomy 

The classic surgical approach to Hirschsprung’s disease consisted of a multiple-stage procedure. This included a colostomy in the newborn period, followed by a definitive pull-through operation after the child weighed >10 kg. But now it is well established that a primary pull-through procedure can be performed safely, even in the newborn period. This approach follows the same treatment principles as a staged procedure and saves the patient from an additional operation.

Ans. C: Rectosigmoid part

Ans. D: Rectal biopsy

The most cited feature is absence of ganglion cells: notably in males, 75% have none in the recto-sigmoid, and 8% with none in the entire colon.

The enlarged section of the bowel is found proximally, while the narrowed, aganglionic section is found distally; the absence of ganglion cells results in a persistent over-stimulation of nerves within the affected region, resulting in contraction.

• Delayed passage of meconium.
• ‘abdominal distension.
• Constipation.

Suspect Hirschsprung’s in a baby who has not passed meconium within 48 hours of delivery. (Recall that 90% of babies pass their first meconium within 24 hours, and the next 9% within 48 hours.)

Definitive diagnosis is made by biopsy of the distally narrowed segment.

Ans. is ‘b’ i.e., Loss of intrinsic enteric plexuses

Pathogenesis of Hirchsprung disease

• The entric neuronal plexuses develops from neural crest cells, which migrate into the bowel wall during develop­ment, mostly in a cephalad to caudad direction.
• Hirschsprung disease results when the migration of neural crest cells arrests at some point before reaching the anus → inappropriate premature death.
• This produces an intestinal segment that lacks both meissner submucosal and aurebach myenteric plexus.
• Loss of enteric neural coordination leads to functional obstruction and intestinal dilation proximal to the affected segment.