Common hepatic artery

The common hepatic artery is one of the three major branches of the celiac trunk, which arises from the abdominal aorta. It supplies blood to the liver, stomach, duodenum, pancreas, and gallbladder through its branches.

Location

The common hepatic artery is located in the upper abdomen, originating from the celiac trunk shortly after it emerges from the abdominal aorta. It travels to the right, crossing the upper part of the pancreas and descending towards the liver. Along its course, it gives off several important branches, including the gastroduodenal artery and the right gastric artery, before continuing as the hepatic artery proper toward the liver. The artery is situated within the hepatoduodenal ligament, which connects the liver to the duodenum, and is part of the portal triad, alongside the portal vein and bile duct.

Structure and Anatomy

Origin

The common hepatic artery originates from the celiac trunk, a major arterial branch of the abdominal aorta. The celiac trunk arises at the level of the twelfth thoracic vertebra (T12), just below the diaphragm, and divides into three main branches: the left gastric artery, splenic artery, and common hepatic artery. The common hepatic artery is one of these key branches and supplies blood to the liver and several other organs in the upper abdomen.

Course

After branching from the celiac trunk, the common hepatic artery runs horizontally to the right side of the abdomen. It passes posterior to the lesser omentum, a double layer of peritoneum that connects the stomach and liver. As it continues, it courses along the superior aspect of the pancreas, just above the pancreatic head.

The common hepatic artery runs anterior to the portal vein and, along its course, is closely related to structures such as the stomach and duodenum. It continues toward the right, heading toward the liver, and terminates by dividing into the hepatic artery proper and the gastroduodenal artery.

Branches

The common hepatic artery gives off several key branches along its course:

• Right Gastric Artery: The right gastric artery typically arises from the common hepatic artery and supplies the lesser curvature of the stomach. It runs along the stomach’s lesser curvature and forms an anastomosis with the left gastric artery.
• Gastroduodenal Artery: One of the largest and most important branches, the gastroduodenal artery arises from the common hepatic artery and travels posterior to the first part of the duodenum. It supplies blood to the stomach, duodenum, and pancreas through its branches, including the right gastroepiploic artery and the superior pancreaticoduodenal artery.

After giving off these branches, the common hepatic artery continues as the hepatic artery proper, which ascends toward the liver within the hepatoduodenal ligament.

Relations

• Anteriorly: The common hepatic artery is covered by the peritoneum and lies posterior to the stomach. It is related to the pyloric region of the stomach as it runs towards the liver.
• Posteriorly: The common hepatic artery lies anterior to the portal vein, which is part of the portal triad along with the common bile duct. The artery is also related to the head of the pancreas, which lies beneath the artery.
• Superiorly: The celiac trunk and its other branches (the left gastric artery and splenic artery) are located superior to the common hepatic artery.
• Inferiorly: The first part of the duodenum lies inferior to the artery, particularly near the gastroduodenal artery, which courses downward.

Length and Diameter

The common hepatic artery is relatively short in length, measuring around 4-6 cm from its origin at the celiac trunk to its bifurcation into the hepatic artery proper and the gastroduodenal artery. Its diameter varies between individuals but is typically around 5-7 mm, large enough to supply oxygenated blood to several organs in the upper abdomen.

Termination

The common hepatic artery terminates by dividing into two primary branches:

• Hepatic Artery Proper: This artery ascends toward the liver within the hepatoduodenal ligament and supplies the liver, gallbladder, and parts of the stomach. It further divides into the right and left hepatic arteries at the porta hepatis.
• Gastroduodenal Artery: The gastroduodenal artery descends behind the first part of the duodenum and gives rise to important branches like the right gastroepiploic artery and superior pancreaticoduodenal artery, which supply the stomach, duodenum, and pancreas.

Anatomical Variations

Anatomical variations in the common hepatic artery are common and can include:

• Origin Variations: In some individuals, the common hepatic artery may arise directly from the aorta instead of the celiac trunk. Alternatively, it may have an aberrant origin from the superior mesenteric artery or another nearby vessel.
• Branching Variations: The branches of the common hepatic artery, such as the right gastric artery or gastroduodenal artery, may originate at different levels or follow slightly different courses. In some cases, additional small arteries may arise from the common hepatic artery to supply nearby tissues.

Blood Supply Regions

The common hepatic artery and its branches supply blood to a variety of important organs and regions, including:

• The liver via the hepatic artery proper.
• The stomach via the right gastric and right gastroepiploic arteries.
• The duodenum via the gastroduodenal and superior pancreaticoduodenal arteries.
• The gallbladder via the cystic artery, which typically arises from the right hepatic artery.

Function

The common hepatic artery is a critical vessel responsible for supplying oxygenated blood to several key organs in the upper abdomen. Through its branches, it delivers blood to the liver, stomach, pancreas, duodenum, and gallbladder, supporting their metabolic and digestive functions. Below is a detailed description of the specific functions of the common hepatic artery based on the regions it supplies.

Blood Supply to the Liver

One of the primary functions of the common hepatic artery is to provide blood to the liver through its continuation as the hepatic artery proper. This blood supply is essential for:

• Oxygen Delivery: The liver requires a substantial amount of oxygen to perform its many metabolic processes, including detoxification, bile production, and metabolism of fats, carbohydrates, and proteins. The common hepatic artery, through its branches, ensures the delivery of oxygen-rich blood to the liver’s parenchymal cells (hepatocytes).
• Nutrient Support: In addition to oxygen, the blood supplied by the hepatic artery proper carries essential nutrients needed by the liver to perform its critical functions. This blood supply is independent of the portal vein, which brings nutrient-rich blood from the gastrointestinal tract.

Blood Supply to the Gallbladder

The common hepatic artery indirectly supports the gallbladder through its branch, the cystic artery, which usually arises from the right hepatic artery, a branch of the hepatic artery proper. The cystic artery provides blood to:

• Gallbladder Function: The blood supplied by the cystic artery ensures that the gallbladder’s muscular walls receive enough oxygen to store and release bile, which is essential for fat digestion in the small intestine.
• Bile Concentration: The gallbladder concentrates bile by absorbing water and electrolytes. The blood supply from the cystic artery supports the metabolic needs of the cells involved in this process, ensuring optimal bile storage and release during digestion.

Blood Supply to the Stomach

The common hepatic artery supplies blood to parts of the stomach through its branches, particularly the right gastric artery and right gastroepiploic artery:

• Right Gastric Artery: The right gastric artery arises from the common hepatic artery and supplies the lesser curvature of the stomach. It provides blood to the stomach’s mucosal lining, supporting the production of gastric acid, mucus, and enzymes involved in digestion.
• Right Gastroepiploic Artery: The right gastroepiploic artery, a branch of the gastroduodenal artery, supplies the greater curvature of the stomach. It supports the stomach’s muscular layer for peristalsis (contractions that mix food with digestive juices) and aids in maintaining the health of the stomach’s protective mucosal lining.

Blood Supply to the Duodenum

The gastroduodenal artery, a major branch of the common hepatic artery, supplies blood to the duodenum through the superior pancreaticoduodenal artery. This blood supply is essential for:

• Digestive Function: The duodenum is responsible for the initial stages of digestion after food leaves the stomach. The superior pancreaticoduodenal artery provides oxygen to the duodenal wall, supporting its absorptive and digestive functions.
• Protection Against Acidic Chyme: The blood supply to the duodenum supports the production of bicarbonate-rich mucus, which helps neutralize the acidic chyme coming from the stomach, preventing damage to the duodenal lining.

Blood Supply to the Pancreas

The superior pancreaticoduodenal artery, another branch of the gastroduodenal artery, supplies blood to the head of the pancreas. This artery ensures that the pancreas receives adequate oxygen and nutrients to perform its dual functions:

• Exocrine Function: The pancreas produces digestive enzymes (amylase, lipase, proteases) that are released into the duodenum. The blood flow from the superior pancreaticoduodenal artery ensures that the pancreatic acinar cells have the oxygen and nutrients needed for enzyme production and secretion.
• Endocrine Function: The pancreas also produces hormones such as insulin and glucagon that regulate blood sugar levels. The blood supplied by the superior pancreaticoduodenal artery ensures that the endocrine islets (Islets of Langerhans) are well-nourished, supporting hormone secretion.

Oxygen and Nutrient Delivery

As with all arteries, the primary function of the common hepatic artery is to deliver oxygen and nutrients to the tissues it supplies. This process is essential for:

• Cellular Metabolism: The cells in the liver, stomach, gallbladder, pancreas, and duodenum require a constant supply of oxygen to perform cellular respiration, which generates the energy needed for digestion, metabolism, and other functions. The common hepatic artery ensures that these organs receive the oxygen they need to maintain normal metabolic processes.
• Tissue Maintenance and Repair: The organs supplied by the common hepatic artery are subject to constant wear and tear, especially during digestion. The blood flow from the common hepatic artery supports the repair and regeneration of damaged tissues, ensuring that these organs remain healthy and functional.

Contribution to Anastomotic Circulation

The common hepatic artery contributes to a network of anastomoses (connections) with other arteries, ensuring continuous blood supply to critical organs:

• Anastomosis with the Left Gastric Artery: The right gastric artery, a branch of the common hepatic artery, forms an anastomosis with the left gastric artery along the lesser curvature of the stomach. This anastomotic network ensures that the stomach receives a continuous blood supply from multiple sources, preventing ischemic damage.
• Anastomosis with the Inferior Pancreaticoduodenal Artery: The superior pancreaticoduodenal artery forms an anastomosis with the inferior pancreaticoduodenal artery, which arises from the superior mesenteric artery. This connection provides collateral blood flow to the pancreas and duodenum, ensuring that these organs receive blood from both the celiac and superior mesenteric arterial systems.

Clinical Significance

The common hepatic artery is clinically significant due to its essential role in supplying oxygenated blood to several key abdominal organs, including the liver, stomach, pancreas, duodenum, and gallbladder. It is crucial during hepatobiliary surgeries, such as liver resections and liver transplants, where preservation of its blood flow is vital for organ function.

In cases of peptic ulcers or duodenal ulcers, the artery or its branches, such as the gastroduodenal artery, may be eroded, leading to life-threatening hemorrhages. Additionally, variations in the anatomy of the common hepatic artery are common, and these must be identified during surgeries like Whipple procedure (pancreaticoduodenectomy) to avoid accidental damage.