Chapter 17 part 1--GI tract--Congenital Abnormalities and Esophagus Flashcards
(73 cards)
1
Q
Congenital Abnormalities–List (4)
A
- Atresia
- Fistula
- Duplication
- Stenosis
2
Q
When and how do artesias, fistulas, and duplications present? Tx?
A
- When in esophagus, they present shortly after birth with regurgitation during feeding
- need prompt surgical correction!
3
Q
Esophageal atresia is also associated with??
A
- Congenital heart defects
- Genitourinary malformation
- neurologic disorders
4
Q
Esophageal Atresia
A
-portion of conduit is replaced by a thin, non canalized cord with blind pouches above and below atretic segment
5
Q
Most common form of esophageal atresia
A
-Imperforate anus–caused by failure of cloacal membrane to involute
6
Q
Esophageal fistula
A
- Connection between esophagus and trachea or a mainstem bronchus
- Swallowed material or gastric fluids can enter respiratory tract
7
Q
Esophageal stenosis
A
- Incomplete form of atresia
- lumen is reduced by a fibrous thickened wall
- can be congenital or result from inflammatory scarring (from chronic reflux, irradiation or scleroderma)
8
Q
Congenital duplication cysts
A
- cystic masses with redundant smooth muscle layers
- can occur throughout the GI tract
9
Q
Diaphragmatic hernia
A
- occurs when incomplete formation of diaphragm allows cephalad displacement of abdominal viscera
- when substantial, subsequent pulmonary hypoplasia is incompatible with postnatal life
10
Q
Omphalocele
A
- occurs when abdominal musculature is incomplete and viscera herniates into ventral membranous sac
- 40% associated with other birth defects
11
Q
Gastroschisis
A
-similar to omphalocele except that all layers of abdominal wall (from peritoneum to skin) fail to develop
12
Q
Ectopia–most common site?
A
- Ectopic tissues common in GI tract
- most common site=PROXIMAL ESOPHAGUS leading to dysphagia and esophagitis
- can also occur in small bowel or colon presenting with occult blood loss or peptic ulceration
13
Q
Pancreatic heterotopia
A
- also an ectopia
- occurs in esophagus and stomach
- in pylorus, it can cause inflammation, scarring and obstruction
14
Q
true diverticulum
A
-blind pouch leading off the alimentary tract, lined by mucosa and includes all 3 layers of bowel wall–mucosa, submucosa, and muscular propria
15
Q
Most common true diverticulum is? cause?
A
- Meckel diverticula (2% of population)
- results from persistence o the vitelline duct (connecting yolk sac and gut lumen) leaving a solitary out pouching within 85 cm of ileocechal valve
16
Q
Meckel’s diverticulum–male vs. female and consequences
A
- male to female ratio is 2:1
- Heterotopic gastric mucosa or pancreatic tissue can be present and can cause peptic ulceration
17
Q
Congenital hypertrophic pyloric stenosis–incidence, M/F ratios and associations
A
- 1/500 births
- 4:1 male to female
- complex polygenic inheritance
- Associated with Turner syndrome and trisomy 18!!
- Also associated with exposure to erythromycin or analogue in first 2 weeks of life
18
Q
Congenital hypertrophic pyloric stenosis–clinical presentation
A
- regurgitation and projectile vomiting wishing 3 weeks of brith
- externally visible peristalsis and a palpable firm ovoid mass
19
Q
Congenital hypertrophic pyloric stenosis–Tx
A
-Full-thickness, muscle-splitting incision (myotomy) is curative!!
20
Q
Acquired pyloric stenosis
A
-complication of chronic antral gastritis, peptic ulcers close to pylorus and malignancy
21
Q
Hirschsprung Disease
A
- Aka congenital aganglionic megacolon!
- results from arrested migration of neural crest cells into gut, yielding ganglionic segment lacking peristaltic contractions
- Functional obstruction, proximal dilation, progressive dilation and hypertrophy of unaffected proximal colon
- 1/5000 live births
22
Q
Hirschsprung Disease–organ involvement
A
- Rectum is ALWAYS affected!!
- Proximal involvement is more variable
23
Q
Pathogenesis of Hirschsprung Disease–genetic
A
- usually has genetic component–heterozygous LoF mutations in RET tyrosine kinase receptor in 15% of sporadic cases and majority of familial cases
- More than 7 other genes involved in enteric neurodevelopment also associated
- Penetrance is incomplete influenced by sex-linked factors (males 4x more commonly affected!!) and other genetic and environmental modifiers
24
Q
Clinical features of Hirschsprung Disease
A
- presents with neonatal failure to pass meconium or abdominal distention with severely distended megacolon (several cm in diameter!)
- risk of perforation, sepsis, or enterocolitis with fluid derangement
25
Acquired megacolon
- occur in Chagas disease, bowel obstruction, IBD, and psychosomatic disorders
- Ganglia actually lost ONLY IN CHAGAS!!
26
Esophageal Obstruction--can cause dysphagia especially with sold foods--causes
- Stenosis
- Spasm
- Diverticula
- Mucosal webs
- Esophageal rings
27
Esophageal obstruction--spasm
-can be short or long lived, focal or diffuse
28
Diffuse esophageal spasm
- causes functional obstruction
| - increased wall stress can cause diverticula to form!
29
Esophageal diverticula
- can contain one or more layers
| - if sufficiently large, they can accumulate enough food to present as a mass with food regurgitation
30
3 types of esophageal diverticula
- Zenker (pharyggeoesophageal)
- Traction diverticulum
- Epiphrenic diverticulum
31
Zener (pharyngeoesophageal) diverticulum occurs where?
-occurs immediately above upper esophageal sphincter
32
Traction diverticulum occurs where?
-occurs at esophageal midpoint
33
Epiphrenic diverticulum--occurs where?
-occurs immediately above the lower esophageal sphincter (LES)
34
Mucosal webs
- ledgelike protrusions of fibrovascular tissue and overlying epithelium
- most common in the upper esophagus
- women over 40!!
- constellation of webs, iron deficiency anemia, glossitis and cheilosis
- Plummer-Vinsion syndrome
35
Plummer-Vision syndrome
- aka Paterson-Brown Kelly syndrome
| - constellation of webs, iron deficiency anemia, glossitis, and cheilosis
36
Esophageal rings (Schatzie rings)
- Similar to webs but are circumferential and thicker
| - include mucosa, submucosa and occasionally hypertrophic muscular propria
37
A rings vs. B rings (esophageal rings)
- A rings=ABOVE the gastroesophageal (GE) junction; have SQUAMOUS EPITHELIUM
- B rings: located at the SQUAMOCOLUMNAR junction; can have gastric-cardia type mucosa
38
Achalasia
-triad of incomplete relaxation of LES, increased LES tone (due to cholinergic signaling) and esophageal aperistalsis
39
Primary achalasia
- idiopathic
- cause: from failure of distal esophageal neurons to induce LES relaxation during swallowing (normally driven by nitric oxide and vasoactive intestinal peptide signaling
- can also happen with degenerative changes in neural innervation
40
Secondary achalasia
- can occur with:
- Chagas disease (Trypanosome cruzi)
- Disorders of the vagal dorsal motor nuclei (polio, surgical ablation)
- Diabetic autonomic neuropathy, in association with Down syndrome and infiltrative disorders (malignancy, amyloidosis, sarcoidosis
41
Allgrove (Triple A syndrome)
- Autosomal recessive disorder
| - characterized by achalasia, alacrima, and adrenocorticotropic hormone-resistant adrenal insufficiency
42
Treatment for achalasia
-myotomy, balloon dilation, and/or botulinum toxin injection to inhibit LES cholinergic neurons
43
Esophagitis--causes/types
- Lacerations
- Chemical and Infectious Esophagitis
- Reflux esophagitis
- Eosinophilic Esophagitis
- Esophageal Varices
44
Esophageal Lacerations leading to esophagitis
- Mallory Weiss Tears
| - Boerhaave syndrome
45
Mallory-Weiss tears
- longitudinal lacerations (mm to cm in length) at GE junction associated with excessive vomiting--associated with alcohol intoxication
- reflex relaxation of the LES precedes anti peristaltic wave associated with vomiting
- with prolonged vomiting, relaxation fails, resulting in esophageal stretching and tearing
46
Mallory-Weiss tears presentation
- typically present with hematemesis
- 10% of upper GI bleeding is associated with such tears
- not fatal; healing is prompt without surgery
47
Boerhaave syndrome
- In contrast to Mallory-Weiss tears, this is much less common but more serious
- involve transmural rupture of distal esophagus with severe mediastinhtis
- surgical intervention required!
48
Chemical and Infectious esophagitis--agents that can damage esophageal epithelium
- alcohol
- corrosive acids or alkalis
- excessively hot fluids
- heavy smoking
- Pills that lodge and dissolve in esophagus
- irradiation
- chemotherapy
- graft vs. host disease (GVHD)=iatrogenic etiology
49
Esophagitis associated with was systemic desquamative disorders?
- Pemphigoid
- Epidermolysis bulls
- Crohns disease (CD)
50
Infections associated with esophagitis; who does this happen in?
- immunocompromised
- HSV
- CMV
- Fungal infections (candida most common!)
51
Chief symptoms of chemical and infectious esophagitis
- pain and dysphagia (pain with swallowing)
| - in severe and chronic cases, hemorrhage, stricture or perforation can result
52
Morphology of chemical and infectious esophagitis
- depends on etiology
- most common=dense neutrophilic infiltrates, although chemical injury may initially cause outright necrosis with inflammation
- Any epithelial ulceration is accompanied by granulation tissue and eventually fibrosis
53
Candidiasis esophagitis morphology
-when severe is associated with adherent gray-white PSEUDOMEMBRANES composed of densely matted fungal hyphae and inflammatory cells
54
HSV esophagitis morphology vs. CMV esophagitis
- HSV causes punched out ulcers
| - CMV presents with shallower ulcerations with characteristic viral inclusions!
55
Esophageal GVHD lesions and blistering disorders
-resemble their counterparts in the skin
56
Reflux esophagitis
- Reflux of gastric contents is the foremost cause of esophagitis!!!
- clinical condition is called GERD (gastroesophageal reflux disease)
57
Pathogenesis of reflux esophagitis
- Reflux of gastric juices is the major source of mucosal injury
- in severe cases, duodenal bile reflux exacerbates damage
58
Reflux is caused by
- decreased LES tone and/or increased abdominal pressure and can be caused by alcohol, tobacco use, obesity, CNS depressants, pregnancy, delayed gastric emptying or increased gastric volume
- Hiatal hernia also causes GERD
59
Hiatal hernia
- can cause GERD
- occurs when diaphragmatic crura are separated and the stomach protrudes into thorax
- Hiatal hernias can be congenital or acquired; <10% are symptomatic!
60
Morphology of reflex esophagitis
- Hyperemia and edema
- Basal zone hyperplasia (exceeding 20% of epithelium) and thinning of superficial epithelial layers
- Neutrophil and/or eosinophil infiltration
61
Clinical features of GERD
- most common in adults older than 40 yrs
| - S/S: dysphagia, heartburn and regurgitation of gastric contents into mouth
62
Complications of long standing reflux include
- ulceration
- hematemesis
- melena
- stricture
- Barrett esophagus
63
Symptomatic relief of GERD
- with reduced mucosal damage only
| - use PPIs and or H2 histamine receptor antagonists
64
Eosinophilic Esophagitis presentation
- food impaction and dysphagia
| - children with feeding intolerance and GERD-like symptoms
65
Cardinal histologic feature of Eosinophilic Esophagitis is
-Large numbers of intraepithelial eosinophils!!
66
Other conditions associated with Eosinophilic Esophagitis? Tx?
- Many atopic disorders like atopic dermatitis, asthma
| - Tx for esophageal disorder involves dietary restriction and/or stroids
67
Pathogenesis of Esophageal varices
- Severe portal HTN induces collateral bypass channels between prowl and naval circulations
- lead to congested subepithelial and submucosal veins in distal esophagus (varies)
68
Most common cause of esophageal varicies in Western world? second most common cause worldwide?
- Alcoholic cirrhosis!!
- 90% of cirrhotic patients develop varicose!
- second most common cause=hepatic schistosomiasis!!
69
Morphology of esophageal varicies
- Tortuous, dilated veins are present in distal esophageal and proximal gastric submucosa
- irregular luminal protrusion of overlying mucosa with superficial ulceration, inflammation or adherent blood clots
70
Clinical features of esophageal varicies
- Varices present in almost half of patients with cirrhosis
| - clinically silent until they rupture with hematemesis (50-80% of patients with varies)
71
Causes of rupture of esophageal varicies
- inflammatory erosion
- increased venous pressure
- increased hydrostatic pressure associated with vomiting
72
Bleeding from esophageal varies can be treated with?
- sclerotherapy
- balloon tamponade or
- band ligation
73
Esophageal varicies prognosis
- Up to half die with their first bleed either due to exsanguination or following hepatic coma
- in survivors there is a 50% change of recurrence within a year with the same mortality rate
