2. Developmental Anomalies
• Atresia The complete failure of development of the intestinal lumen.
• Stenosis Narrowing of the intestinal lumen with incomplete obstruction.
• Duplication
• Meckel diverticulum (A pouch or sac branching out from a hollow organ or structure, such as the intestine).
It results from failure of involution of the omphalomesenteric duct, leaving a persistent blind-ended tubular
protrusion as long as 5 to 6 cm.
• Omphalocele a congenital defect of the periumblical abdominal musculature that creates a membranous sac,
into which the intestines herniate.
• Gastroschisis- extrusion of the intestines through the absent portion of the abd. Wall.
• Malrotation
•Hirschsprung disease
3. Hirschsprung disease
• Hirschsprung disease is a developmental disorder
of the enteric nervous system and is
characterized by an absence of ganglion cells in the
distal colon resulting in a functional obstruction.
Congenital
Aganglionic
Megacolon
4. Hirschsprung's disease, or
congenital aganglionic megacolon
involves an enlargement of the colon, caused by
bowel obstruction resulting from an aganglionic
section of bowel (the normal enteric nerves are
absent) that starts at the anus and progresses
upwards.
• The length of bowel that is affected varies but seldom
stretches for more than about 30 cm.
• This disease is named after Harald Hirschsprung, the
Danish physician who first described the disease in
1886
Ruysch in 1691 a Dutch anatomist, described a 5-year-old girl who died of intestinal obstruction
5. • The first clinical description of Hirschsprung's
Disease was presented at the Berlin Society of
Pediatrics in 1886 by Hirschsprung. He thought that
the disease was caused by distention of
the colon, as evidenced by the title of his
presentation: "Constipation in
Newborns Due to Dilation and
Hypertrophy of the Colon."
6. Pathophysiology
• Congenital aganglionosis of the distal bowel defines
Hirschsprung disease. Both the myenteric
(Auerbach) plexus and the submucosal (Meissner)
plexus are absent, resulting in reduced bowel
peristalsis and function. The precise mechanism
underlying the development of Hirschsprung
disease is unknown.
7. Enteric ganglion cells are derived from the
neural crest.
During normal development, neuroblasts will be
found in the small intestine by the 7th week of
gestation and will reach the colon by the 12th week
of gestation. One possible etiology for Hirschsprung
disease is a defect in the migration of these
neuroblasts down their path to the distal intestine.
8. • Alternatively, normal migration may occur with a
failure of neuroblasts to survive, proliferate, or
differentiate in the distal aganglionic segment.
• Abnormal distribution in affected intestine of
components required for neuronal growth and
development, such as fibronectin, laminin, neural
cell adhesion molecule (NCAM), and neurotrophic
factors, may be responsible for this theory.
9. • Additionally, the observation that the smooth
muscle cells of aganglionic colon are
electrically inactive when undergoing
electrophysiologic studies also points to a
myogenic component in the development of
Hirschsprung disease.
11. Epidemiology
• Rate of occurence 1 case per 5000 live births.
• Race
• Hirschsprung disease has no racial predilection.
• Sex
• Hirschsprung disease occurs more often in
malesthan in females, with a male-to-female
ratio of approximately 4:1.
• However, with long-segment disease, the incidence
increases in females.
12. • Age
• Hirschsprung disease is uncommon in
premature infants.
• The age at which Hirschsprung disease is
diagnosed has progressively decreased over
the past century. In the early 1900s, the
median age at diagnosis was 2-3 years; from
the 1950s to 1970s, the median age was 2-6
months.
13. • Currently, approximately 90% of patients with
Hirschsprung disease are diagnosed in the
newborn period.
15. Diagnosis
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 suction biopsy of the
distally narrowed segment.
16.
17. Abdominal x-ray - show a lack of stool in the large
intestine or near the anus and dilated segments of
the large and small intestine.
Barium enema - An x-ray of the abdomen shows
strictures (narrowed areas), obstructions
(blockages), and dilated intestine above the
obstruction.
18. Anorectal manometry - a test that measures
nerve reflexes which are missing in
Hirschsprung's disease.
Biopsy of the rectum or large intestine - a test
that takes a sample of the cells in the rectum
or large intestine and then looks for nerve
cells under a microscope.
21. Definitions
• celiac sprue is an immune disorder(autoimmune)
characterized by inflammation of the
proximal small intestine induced by the ingestion of
gluten
• also known as celiac disease and gluten-sensitive enteropathy
22. • Celiac disease is a condition that damages the
lining of the small intestine and prevents it
from absorbing parts of food that are
important for staying healthy. The damage is
due to a reaction to eating gluten, which is
found in wheat, barley, rye, and possibly oats.
23. 23
• Occurs in genetically susceptible individuals
• A unique autoimmune disorder because:
– both the environmental trigger (gluten) and
the autoantigen (tissue Transglutaminase) are
known
–elimination of the environmental
trigger leads to a complete
resolution of the disease
24. Pathogenesis: Environmental
• glutens are water-insoluble grain proteins
(prolamins and glutenins)
• taxonomy of grains predicts their toxicity in patients
Gramineae
Triticum Secale Hordeum Avena Oryza Zea Sorghum Pennisetum
family
genus
wheat rye barley oats rice corn sorghum millet grain
gliadin
secalin hordein avenin oryzenin zein kafirin panicin gluten
immunologic
cross-reactivity
34. What is the tropical sprue?
Tropical sprue: is a malabsorption disease
commonly found in the tropical regions,
marked with abnormal flattening of the villi
and inflammation of the small intestinal
mucosa.
35. Causes
- No specific causal agent has been clearly
associated with tropical sprue, but
bacterial overgrowth by enterotoxigenic
organisms ( e.g., E.coli and hemophilus )
has been implicated.
36. Morphology
- Intestinal changes range from near normal to
severe diffuse enteritis.
- Unlike celiac sprue, injury is seen at all levels
of the small intestine.
37. -Patients frequently have folate and vitamin
B12 deficiency, leading to enlargement of
the nuclei of epithelial cells , reminiscent of
the changes seen in pernicious anemia.
38. Symptoms
The symptoms of tropical sprue are:
- Diarrhea.
- Indigestion.
- Cramps.
- Weight loss and malnutrition.
- Fatigue.
39. Signs
- Abnormal flattening of villi and inflammation
of the lining of the small intestine, observed
during an endoscopic procedure.
- Presence of inflammatory cell in the biopsy of
small intestine tissue .
40. - Low levels of vitamins A, B12, E, D, and K,
as well as albumin, calcium, and folate,
revealed by a blood test.
- Excess fat in feces
41. Management
- Prevention:-
Preventions of tropical sprue include
avoiding travel to the affected regions.
If you have to travel, remember to use only
bottled water for drinking, brushing teeth,
and washing food .
-Nutritional deficiencies must also be corrected.
42. Treatment:-
Treatment is usually 3 to 6 months of
antibiotics (tetracycline) and folic acid
supplements. People with vitamin B12
deficiency will receive vitamin supplements as well.
Editor's Notes
Grass family. These 4 are closely related enough to cross-react, but oats have far less gluten per gram, so some can tolerate certain amounts once in remission. Humans (hominids) are 3.2 million years old and Homo sapiens is 100,000 years old. But the first farmer dates back only 10,000 years.
Figure 3. Endoscopic and biopsy findings in patients with and without celiac disease. (A) High-definition endoscopic photo of normal small intestine. The villi are clearly visible with no evidence of atrophy or scalloping of the folds. (B) Biopsy specimen of normal small intestine (hematoxylin-eosin; original magnification, × 100). (C) PillCam image of small intestine in a patient with celiac disease, showing scalloping of the mucosal folds (arrows) characteristic of a malabsorption pattern. There is also evidence of villous atrophy compared with normal. (D) Biopsy specimen of small intestine in a patient with celiac disease (hematoxylin-eosin; original magnification, × 100). Note the loss of villous architecture.
Vast majority are asymptomatic or have non-specific symptoms. Usual adult presentation is in 5 th decade. Adult presentation is now more common than childhood presentation. Misdiagnosis as IBS is common. In adults the atypical symptoms are more common than the traditional, typical symptoms.
DH patients tend to have less malabsorption. Hyposplenism causes red cell abnormalities and Howell-Jolly bodies.
