B47 Peptic ulcers Flashcards
What is the difference between an erosion and an ulcer?
Erosion: The damage or atrophy remains limited to the mucosal layer not extending beyond the muscularis mucosae
Ulcer: Damage goes beyond the mucosal layer into the tunica submucosa, tunica muscularis, or serosa.
What defines a peptic ulcer?
Where do they usually occur?
A chronic ulcerative lesion that can occur anywhere in the GI tract, and is due to chronic exposure to acids and digestive enzymes like pepsin. (pepsin secreted from cheif cells, and acids secreted by parietal cells of the stomach.
~80% occur in the first part of the duodenum just after the pylorus, before descending part.
~20% occur in the gastric antrum, usually on the lesser curvature
But they may occur elsewhere, such as in the esophagus from reflux, or in other parts of the stomach.
What causes peptic ulcers?
H. pylori infection or Chronic NSAID use
NSAIDS: inhibit prostaglandins. Prostaglandins directly decrease acid production and increase blood flow.
Also:
Pancreatic Gastrinomas
Chronic alcoholism
Smoking or chewing tabacco
Irradiation
CMV infection - in IC’d like CMV esophagitis, it can cause gastric ulcers as well
Exacerbated by stress
What are the virulence factors of H. Pylori that cause an ulcer?
CagA gene produces vacuolating toxin, damages epithelial cells
Urease, produces weak base ammonia, increases local pH, causes increased acid secretion elsewhere.
Phospholipase and proteases, to breakdown mucous and reach mucosa.
What are the possible complications of peptic ulcers?
Burning epigastric pain that is releived by eating alaline foods or drinks
Nausea, vomiting.
Chronic bleeding, iron deficient anemia
Perforation and acute bleeding, infection, peritonitis
Scarring and stenosis of intestine
Malignant transformation specifically of gastric ulcers, to adenocarcinoma due to metaplasia around the borders.
Dudodenal ulcers do not transform, but H pylori infection does increase risk of MALT lymphoma of the GI tract.
What are the causes of acute erosions/ulcers?
How does the morphology differ from chronic ulcers?
Acute ulcers occur from either
-
Gastrinoma, causing very increased acid secretion throughout stomach. Also called Zollinger-Ellinson syndrome, or as part of MEN-1 syndrome.
- Main symptoms are epigastric pain due to multiple ulcers in the stomach, vomitting, bloody vomit, and diarrhea
- Stress ulcers and may appear after severe physical stress, like shock, cerebral edema, or severe burns.
- Shock induces hypovolemia, decreases blood flow, produces ulcers
- Severe burns do the same thing, and their ulcers have a special name Culring ulcers
- Edema or increased intracranial pressure: causes Cushing ulcers. Increased ICP increases Vagal activity, increases ACh release and acid production.
The major morphological difference is that these ulcers are multifocal occuring in many places in the stomach, whild chronic ulcers are general single.
Theya stain dark brown due to digested blood from acute bleeding.
They may cause acute bleeding which may or may not be vomited.
How is a gastric ulcer different than a duodenal ulcer?
All gastric ulcers must be biopsied to check for malignancy. You can’t tell from gross morphology if it is a benign or cancerous ulcer. In addition to H. pylori and NSAIDS, Adenocarcinoma is a major cause of stomach ulcers.
Duodenal ulcers are virtually always benign, and for whatever reason cancers almost never occur there.
Benign gastric ulcers: Small, “punched out” appearance, hyperemic rim, but the rim is uniform and not extremely thick.
Malignant gastric ulcers: Large, non-uniform border which is thick and folded.
But, the only real way to tell is by biopsy and histology to check for adenocarcinoma.
What are the 3 major signaling molecules that increase acid secretion?
Gastrin, Acetylcholine, and Histamine.
Where is the most common site of H. pylori infection?
The Antrum.
What are the potential complications of a ruptured duodenal ulcer?
Bleeding from the gastroduodenal artery.
Acute pancreatitis
What are the potential complications of rupture of a gastric ulcer?
Bleeding from the left gastric artery
