Chapter 17. Congenital Disorders of the Stomach Flashcards
Disorders of the stomach are a frequent cause of clinical disease, with _______________ lesions being common.
inflammatory and neoplastic lesions
Diseases of the stomach account for nearly _____ of all heath care spending on GI diseases.
1/3
What are the 4 anatomic regions of the stomach?
- Cardia
- Fundus
- Body
- Antrum
RECAP:
- ACh and Histamine => parietal cell => _____________
- Prostaglandins => parietal cells => ________________
- Parietal cells are mostly found in ______ and ____ of stomach, not the _____.
- ACh and Histamine: ↑ acid production
- Prostaglandins: ↓ acid production
- Parietal cells are found in fundus and body, not antrum
What is gastrin?
Released by what?
-
Gastrin is a hormone that stimulates secretion of gastric acid (HCl) by the parietal cells of the stomach
- Released by G cells in the pyloric antrum of the stomach, duodenum, and the pancreas.
The ______ and _____ are lined by mucin-secreting foveolar cells that form small glands.
- Cardia
-
Antrum
- However, also contains endocrine cells, like G-cells, => release gastrin that stimulate parietal cells in fundus and body to secrete acid.
Glands in the ______ and ________ have chief cells, which produce and secrete digestive enzymes like pepsin.
body
fundus
What is the difference between erosion and an ulcer?
- Erosion: loss of epithelial layer that extends into the muscularis mucosa.
- Ulcer: Loss of the mucosal layer that can extend into [submucosa and muscular layer], are usually focal and mostly occur in the stomach and duodenum.
What is gastritis?
Inflammation of the mucosa that is often generalized
What differentiates Acute Gastritis from Gastropathy?
Causes of each?
- Acute gastritis: neutrophils are present
- Causes: Autoimmune or H.pylori
- Gastropathy: gastric mucosal disorder with minimal to no inflammation (no inflammatory cells are present)
- Causes: NSAIDs, EtOH, Bile, Stress
Can gastropathy and acute gastritis be distinguished clinically?
No
Both cause epigastric pain, N/V. If severe, mucosal erosion, ulceration, hemtaemesis, melena.
What mechanisms protect the gastric mucosa?
- Surface mucus secretion
- HCO3- secretion into mucus
- Mucosal blood flow
- Epithelial barrier
- Epithelial regeneration
- Prostaglandins
What NL mechanisms damage the gastric mucosa?
- Gastric acidity
- Peptic enzymes
What causes injury to the gastric mucosa?
- H. pylori
- NSAIDS
- Tobacco and alochol
- Gastric hyperacidity
- Duodenal-gastric reflux
- Ischemia and shock
Ulcers associated with acute and chronic gastritis may include layers of what type of injury? (hint: mnemonic to remember layers)
- Necrotic debris
- Inflammation
- Granulation tissue
- Scar (fibrosis)
*NIGS
What are causes of acute gastritis?
- NSAIDS
- alcohol
- chemo
- H. Pylori
NSAIDs contribute to gastritis how?
Inhibit synthesis of prostaglandin E2 and I2 by COX => inhibit mucus/bicarb/phospholipid secretion/ mucosal BF, epithelial restitution, => increase acid production.
Why are older adults more prone to gastritis?
↓ mucin and bicarb
What is the morphology seen in acute gastritis?
- Surface epithelium is intact
- Foveolar cell hyperplasia that look like corkscrews
- Epithelial proliferation
Presence of _________ above the BM in direct contact w/ epithelial cells is abnormal in all parts of the GI tract and signifies active inflammation (acute/chronic gastritis)
Neutrophils
Concurrent erosion and hemorrhage is called ________.
acute erosive hemorrhagic gastritis
How is the response to PPI’s different if the patient is suffering from NSAID-induced gastropathy vs. pain associated w/ bile reflux?
- NSAID-induced: asymptomatic or have persistent epigastric pain that responds to antacids or PPI’s
- Bile reflux is typically unresponsive and may have occasional bilious vomiting
Severe acute gastritis can result in _______.
Acute gastric ulcerations
Stress-related mucosal diseases occur in patients with severe trauma, burn, incranial diseases, surgery, etc.
Stress ulcers are most common in individuals with what 3 things?
How are they caused?
Common in ______ patients.
1) Shock
2) Sepsis
3) Severe trauma
- => decreased mucosal perfusion, causing loss of protective barrier of mucus and bicarb.
- Common among critically ill patients.
- Like Curlings ulcers => all ICU pts are given prophylactic therapy includes PPIs (pantaprazole, omeprazole, etc)
Stress-related mucosal diseases occur in patients with severe trauma, burn, incranial diseases, surgery, etc.
Ulcers in the prox. duodenum and occur in patients with burns or trauma are called?
-
Curling ulcers (Think curling irons will burn you!)
- Loss of skin => decrease plasma volume => dehydration => hypotension to stomach/ mucosa => damage mucosa). Result: acute gastritis and ulcers
- Give PPIs to any pt that comes in w burns
Stress-related mucosal diseases occur in patients with severe trauma, burn, incranial diseases, surgery, etc.
Gastric, duodenal, and esophageal ulcers that occur in persons w/ ↑ intracranial pressure (tumor or hemorrhage) are termed?
What causes them?
Increase risk of?
- Cushing ulcers
- Increased intracranial pressure => Direct stimulation of vagal nuclei => increase ACh to stomach => hypersecretion of gastric acid => gastritis and ulcers
- *Perforation
The pathogenesis of stress-related gastric mucosal injury is most often due to what?
Hypotension, hypoxia or stressed-induced splanchnic vasoconstriction that cause [local ischemia].
What determines acute vs chronic gastritis?
Types of infiltrates that are seen.
-
Acute gastritis = neutrophil infiltration
- Often due to mucosal damage from acids
-
Chronic gastritis = lymphocytes, plasma cells and MO
- 2 common causes: AI or H.pylori
Symptoms of gastritis
-
Dyspepsia (N, V, loss of appetite, abdominal or epigastric pain)
- Worse w/ food because they cause more acid (H+) secretion.
What are the causes of ischemia seen in stress-related gastric mucosal injury?
- Systemic hypotension
- Stress-induced splanchnic vasoconstriction => ⬇︎ blood flow
- ↑ of inducible NOS
- ↑ release of vasoconstictor endothelin-1
What is the morphology of the acute ulcers seen in stress-related mucosal diseases?
- Sharply demarcated, multiple ulcers less than 1 cm in diamater, found anywhere in the stomach.
- Base of the ulcer is brown (blood) and the adjacent mucosa is NL.
How are acute ulcers in stress-related gastric mucosal injury different from chronic peptic ulcers?
- Multiple and located anywhere in the stomach
- Scaring and thickining of BV is NOT present
Most critically ill patients admitted to ICU have evidence of what damage?
Damage to the gastric mucosa
In critcally ill patients admitted to the ICU, what is the most important determinant of clinical outcome?
- Ability to correct the underlying condition-
Removal of the injurous factor normally causes healing with complete re-repithlialization.
What are the 2 non-stress related causes of gastric bleeding?
- Dielafoy lesions
- GAVE (gastric antral vascular ectasia)
What is a Dieylafoy lesion?
Non-stress related cause of gastric bleeding where there is erosion over a submucosal artery has improper branching of w/i wall of stomach, forming a LARGE mucosal artery.
Where does a Dieufaloy lesion most commonly occur and what causes it?
- Along the lesser curvature, near the GE junction.
- Erosion due to NSAIDS
What is responsible for 4% of non-variceal upper GI bleeding?
GAVE (gastric antral vascular ectasia)
Gastric antral vascular ectasia (GAVE) can be recognized endoscopically how?
Alternating longitudinal stripes of edematous red mucosa w/ pale mucosa that is less injured (“watermelon stomach”)
While often idiopathic, gastric antral vascular ectasia (GAVE) can be associated with what underlying pathologies?
Patients may present how?
- Cirrhosis and Systemic Sclerosis
- Occult fecal blood and iron-deficiency anemia
What are the 2 common causes of chronic gastritis (inflammation + mucosal atrophy, providing a template for dysplasia and cancer to arise)?
- 1. H. Pylori (90%)
- AI gastritis (10%)
How are the symptoms in chronic gastritis different than acute gastritis?
Less severe, more persistant.
N, V, upper abdominal pain, but hematemesis is NOT common.
What type of bacteria is H. Pylori?
Gram (-) rod (baccillus); spiral-shaped
What part of the stomach does H. Pylori and AI gastritis cause chronic gastritis?
- H. Pylori: antrum
- AI gastritis: body and fundus
How does chronic gastritis due to H. pylori progress?
- [Initial antral gastritis] can progress to involve body or fundus
- Multifocal atrophic gastritis, which is patchy mucosal atrophy and ⬇︎ acid production due to ⬇︎ parietal cells,
- Intestinal metaplasia (increase risk of gastric adenocarcinoma)
How does atrophic gastritis caused by H. pylori differ from chronic gastritis?
Atrophic gastritis has a MULTI-FOCAL pattern, not diffuse.
Who is H. pylori most common in?
- Poverty
- Household crowing
- Decreased education
- AA/Mexicans
How does H.pylori cause chronic gastritis?
H.Pylori does not invade mucosa. It sits on top of epithelial cells and secretes a protective barrier to survive in the acidic stomach via urease
- (makes ammonia => protect the bacteria from stomach acid and forms ammonium chloride => damages stomach; ↑ pH => ↑ gastrin release and ↑ acid production)
What are other H. Pyrlori VF?
- Flagella
- Adhesins
- Toxins (CagA) that are involved in disease progression
Who is the primary carrier of H. pylori and how is it transmitted?
- Humans
- Fecal-oral
What 2 malignancies are associated with H.pylori?
- Gastric adenocarcinoma
- MALT lymphoma (B-cell cancer that occurs in stomach and HIGHLY assx with H.pylori infection)
When inflammation caused by H. pylori is limited to the antrum there is an increased risk of?
Duodenal peptic ulcer
Which virulence factor of H. pylori is associated w/ elevated gastric cancer risk and allows for colonization of gastric body causing multifocal atrophic gastritis?
CagA gene
Polymorphisms of which immunologic mediators are associated w/ development of pangastritis, atrophy, and gastric cancer associated w/ H. pylori?
- Increased: TNF and IL-1β
- Decreased: IL-10 (anti-inflammatory)
Which vitamin deficiency is a risk factor for H.pylori-associated gastric cancer?
Iron
What inflammatory infiltrate are characteristic of H. pylori chronic gastritis?
- Gastrin?
- Acid production?
- Other lesions?
- Intraepithelial neutrophils and subepithelial plasma cells
- Gastrin: NL to ↓
- Acid production: ↑ or slightly ↓
- Other lesions: Hyperplastic/inflammatory polyps
Build-up of neutrophils in lumen of gastric pits often seen with H. pylori gastritis can form what?
Pit abcesses
What serology are characteristic of H. pylori chronic gastritis?
- Sequelae?
- MC in?
- AB to H. Pylori
- Peptic ulcer, adenocarcinoma, MALToma
- Low SES, poverty, rural areas
H. pylori displays trophism for which cells and part of stomach?
Gastric epithelia –> antrum
Intense H. pylori infection can lead to inflammatory infiltrates producing what finding that mimics appearance of early cancer?
Thickened rugal folds
Lymphoid aggregates, some with germinal centers are frequently present in H. pylori gastritis and represent an induced form of?
Potential to transform into?
- Induced form of MALT
- Lymphoma