In a patient undergoing ligation of the left gastric artery, which structure is most at risk for ischemia, which venous drainage of the stomach ultimately contributes to portal hypertension, from which artery does the right gastroepiploic artery originate, and why does the duodenal arterial supply reflect its embryologic origin?

Gastric Vascular Anatomy and Clinical Implications

Question 1: Structure at Risk After Left Gastric Artery Ligation

The lesser curvature of the stomach (answer c) is most at risk for ischemia following left gastric artery ligation.

The left gastric artery supplies the lesser curvature along its branches 1. While the stomach has rich collateral circulation that typically prevents ischemia, the lesser curvature receives its primary blood supply from the left gastric artery along the proximal portion and the right gastric artery distally. Ligation of the left gastric artery directly compromises this primary supply route.

Key anatomical considerations:

• The fundus receives blood from short gastric arteries (branches of splenic artery), providing independent collateral supply
• The greater curvature is supplied by the left and right gastroepiploic arteries, which form a robust arcade
• The first part of duodenum receives blood from the gastroduodenal artery and its branches, completely independent of left gastric supply

Clinical pitfall: While the stomach's extensive collateral network usually prevents frank ischemia, the lesser curvature remains vulnerable, particularly in patients with pre-existing vascular compromise or when multiple arterial ligations occur during surgery 2, 3.

---

Question 2: Venous Drainage and Portal Hypertension

Venous drainage of the stomach ultimately contributes to portal hypertension via the portal vein (answer c).

The gastric venous system drains into the portal venous system through multiple routes 4:

Primary drainage pathways:

• Left gastric vein (coronary vein) → portal vein
• Right gastric vein → portal vein
• Left gastroepiploic vein → splenic vein → portal vein
• Right gastroepiploic vein → superior mesenteric vein → portal vein

Portal hypertension implications: The left gastric vein drains the lesser curvature and, in portal hypertension, becomes a major pathway for varices. Type 1 gastroesophageal varices (GOV1) at the lesser gastric curvature originate from the left gastric vein and drain toward esophageal varices and the azygos system 4. This represents collateral flow attempting to bypass the hypertensive portal system, but the primary anatomic drainage remains through the portal vein.

---

Question 3: Origin of Right Gastroepiploic Artery

The right gastroepiploic artery originates from the gastroduodenal artery (answer d).

The gastroduodenal artery arises from the common hepatic artery (a branch of the celiac trunk) and gives rise to the right gastroepiploic artery as one of its terminal branches 5. This is the most consistent anatomical pattern, though variations exist.

Anatomical relationships 1:

• The right gastroepiploic artery courses along the greater curvature
• It anastomoses with the left gastroepiploic artery (from splenic artery) to form the gastroepiploic arcade
• Its branches supply both the anterior and posterior walls of the stomach, with longer branches to the posterior wall 3

Surgical relevance: The gastroduodenal artery's position near the first part of duodenum, common bile duct, and pancreatic head makes it vulnerable during hepatopancreaticobiliary procedures. Understanding its branching pattern is critical for D2 lymphadenectomy and preventing inadvertent vascular injury 5.

---

Question 4: Duodenal Arterial Supply and Embryologic Origin

The duodenum receives blood from both the celiac trunk and superior mesenteric artery (answer c), reflecting its embryologic origin from both foregut and midgut.

Embryologic basis: The duodenum develops from the distal foregut (first and second portions) and proximal midgut (third and fourth portions). This dual embryologic origin is reflected in its dual arterial supply:

Celiac trunk supply (foregut):

• Gastroduodenal artery → superior pancreaticoduodenal arteries
• Supplies the first and second portions of duodenum

Superior mesenteric artery supply (midgut):

• Inferior pancreaticoduodenal arteries
• Supplies the third and fourth portions of duodenum

Clinical significance 5: The gastroduodenal artery serves as the anatomical bridge connecting foregut and midgut arterial territories. This rich dual blood supply with extensive anastomoses between superior and inferior pancreaticoduodenal arcades provides robust collateral circulation, protecting the duodenum from ischemia even when one arterial source is compromised.

Surgical consideration: This vascular anatomy must be preserved during pancreaticoduodenectomy and other procedures involving the duodenum to prevent ischemic complications 5.