Peptic Ulcers: Causes, Pathophysiology, and Complications

Main Cause

• Helicobacter pylori bacteria:
  • Causes approximately 10 million Canadians to be infected.
  • Contributes to gastric and duodenal ulcers.
• Other contributing factors:
  • NSAIDs (e.g., aspirin) and aspirin use.
  • Excessive alcohol and caffeine.
  • Stress and smoking.
  • Chemical injury (e.g., ingestion of corrosives like bleach).

Normal Gastric Protection

• Mucus layer: Protects the gastric wall from HCl.
• pH: Normally about 2, kept acidic for digestion.
• Mucus production: Maintained by mucous cells.

Pathogenesis of Ulcers

• Decreased mucus production:
  • Due to bacterial enzymes degrading proteins and lipids.
  • Affects the mucus barrier, exposing epithelium to acid.
• Reduced blood flow:
  • Caused by vasoconstriction (stress, shock, smoking).
  • Limits nutrients and mucus production.
• Excess acid:
  • Due to hypersecretion of gastrin or vagal overstimulation.
  • High acid levels can damage mucosa if mucus barrier is compromised.
• Chemical injury: Ingestion of caustic substances causes scarring and damage.

Types and Locations

• Gastric ulcers: Located in the stomach lining.
• Duodenal ulcers: Typically in the proximal duodenum (pyloric region).
• Role of anatomy:
  • Ulcers tend to form where the mucosa is most exposed or weakened.

Progression

• Erosion: Ulcer erodes through the mucosa and submucosa.
• Further erosion: Can reach the muscularis layer.
• Bleeding:
  • Ulcer may bleed, causing blood in vomit (hematemesis).
  • Blood might be bright red or dark (melena).
• Perforation:
  • Ulcer causes a hole in the wall.
  • Leads to chemical peritonitis (inflammation in the peritoneal cavity).

Complications

• Hemorrhage:
  • Bleeding can cause shock.
  • May require endoscopic intervention or surgery.
• Perforation:
  • Gastric contents spill into the abdominal cavity.
  • Causes severe inflammation (peritonitis).
• Scarring and stricture:
  • Healing scars can narrow the lumen.
  • Can lead to obstruction and vomiting.
• Muscle layer death:
  • Muscle cells do not regenerate.
  • Scar tissue weakens the wall, increasing perforation risk.

Diagnosis and Treatment

• Imaging:
  • Endoscopy and biopsies.
  • Barium swallow X-rays.
• Testing:
  • Stool tests for H. pylori.
  • Blood tests for hemoglobin and Bilirubin.
• Treatment:
  • Antibiotics for H. pylori.
  • Proton pump inhibitors or H2 blockers to reduce acid.
  • Alleviate symptoms with proper diet and lifestyle.

Prevention

• Avoid NSAIDs, alcohol, caffeine.
• Quit smoking.
• Reduce stress.
• Use medications as prescribed to suppress acid.

Summary

Ulcers are a serious condition that can lead to life-threatening bleeding and perforation if untreated. Early diagnosis and appropriate treatment are vital.