Cardiovascular Anatomy: Gastrointestinal Arteries

Introduction

• The gastrointestinal arteries are divided into three main components:
  • Foregut
  • Midgut
  • Hindgut

Arterial Supply

Foregut

• Supplied by: Celiac Trunk
• Structures included:
  • Lower esophagus
  • Stomach
  • First part of the duodenum
• Main branches of the Celiac Trunk:
  • Left Gastric Artery
  • Splenic Artery
  • Common Hepatic Artery
• Function:
  • Supplies blood to the spleen, liver, and foregut structures

Midgut

• Supplied by: Superior Mesenteric Artery (SMA)
• Structures included:
  • Small intestines
  • Ascending colon
  • Proximal two-thirds of the transverse colon
• Notable points:
  • The SMA can compress the duodenum (SMA syndrome) and the left renal vein (Nutcracker syndrome)
  • Acute mesenteric ischemia can occur if SMA is occluded

Hindgut

• Supplied by: Inferior Mesenteric Artery (IMA)
• Structures included:
  • Distal third of the transverse colon
  • Descending and sigmoid colon
  • Rectum
• Ischemia:
  • Acute mesenteric ischemia is less common with IMA than with SMA

Detailed Examination of Arteries

Celiac Trunk

• Common Hepatic Artery:
  • Gives rise to the Hepatic Artery Proper, which supplies the liver
  • Part of the portal triad
  • Gives rise to the Gastroduodenal Artery, which can hemorrhage with posterior duodenal ulcers
• Left Gastric Artery:
  • Supplies the lesser curvature of the stomach
  • Can hemorrhage with gastric ulcers
• Splenic Artery:
  • Supplies the spleen and fundus of the stomach
  • Short gastric artery supplies the gastric fundus

Superior Mesenteric Artery

• Arises: Near the L1 vertebra
• SMA Syndrome:
  • Compression of the third part of the duodenum leads to small bowel obstruction
• Nutcracker Syndrome:
  • Compression of the left renal vein
• Acute Mesenteric Ischemia:
  • Occurs from blockage leading to ischemia of midgut structures

Inferior Mesenteric Artery

• Supplies: Hindgut
• Ischemia:
  • Less common than with SMA

Clinical Correlations

• Gastric Ulcers:
  • Occur on the lesser curvature of the stomach
  • Can result in hemorrhage of left and right gastric arteries
• Duodenal Ulcers:
  • More common anteriorly, but posterior ulcers can cause gastroduodenal artery hemorrhage

Review Questions

1. Question about gastric ulcers: Focus on the lesser curvature and its arterial supply.
2. Compression of the duodenum: Consider the implications of decreased fat storage and artery compression leading to Nutcracker syndrome.

Conclusion

• Understanding the anatomy and arterial supply of the gastrointestinal tract is crucial for diagnosing and managing related clinical conditions.