Celiac artery

The celiac artery, also known as the celiac trunk, is a major arterial branch of the abdominal aorta that supplies blood to several key abdominal organs. It is one of the first major arteries to branch off the aorta after it passes through the diaphragm.

Location

The celiac artery originates from the abdominal aorta at the level of the twelfth thoracic vertebra (T12), just below the diaphragm. It arises in the upper abdomen and quickly divides into three main branches: the left gastric artery, splenic artery, and common hepatic artery. These branches supply oxygenated blood to the stomach, liver, spleen, pancreas, and parts of the duodenum. The celiac artery is located anterior to the vertebral column and the pancreas, and it is surrounded by the celiac plexus, a network of nerves that supply the abdominal organs.

Structure and Anatomy

Origin

The celiac artery, also known as the celiac trunk, originates from the abdominal aorta just below the diaphragm at the level of the twelfth thoracic vertebra (T12). It is one of the first major arterial branches to emerge from the abdominal aorta as it descends into the abdominal cavity. The celiac artery is a short but wide artery that supplies several vital organs in the upper abdomen.

Course

After emerging from the abdominal aorta, the celiac artery extends anteriorly and slightly to the right, usually spanning only about 1-2 cm before it divides into its three primary branches:

• Left gastric artery
• Splenic artery
• Common hepatic artery

These branches immediately distribute oxygenated blood to the stomach, liver, spleen, pancreas, and parts of the duodenum. Despite its short length, the celiac artery plays a crucial role in supplying blood to much of the upper digestive system.

Branches

The celiac artery divides into three main branches, each with its own course and subdivisions:

• Left Gastric Artery:The left gastric artery is the smallest branch of the celiac artery. It ascends upward and slightly to the left toward the esophageal hiatus, supplying the lower esophagus. It then curves along the lesser curvature of the stomach, where it supplies blood to the upper part of the stomach. It anastomoses with the right gastric artery along the lesser curvature.
• Splenic Artery:The splenic artery is the largest branch of the celiac trunk and takes a tortuous course to the left, traveling along the superior border of the pancreas toward the spleen. Along its course, it gives off several branches, including:
  • Short gastric arteries: Supply the fundus of the stomach.
  • Left gastroepiploic artery: Supplies the greater curvature of the stomach and anastomoses with the right gastroepiploic artery.
  • Pancreatic branches: Supply the body and tail of the pancreas.
  • The splenic artery terminates by entering the hilum of the spleen, where it divides into smaller arteries to supply the spleen.
• Common Hepatic Artery:The common hepatic artery travels to the right side of the abdomen and supplies the liver, duodenum, gallbladder, and pancreas. It gives rise to important branches, including:
  • Gastroduodenal artery: Supplies the stomach, duodenum, and pancreas through its branches (right gastroepiploic artery and superior pancreaticoduodenal artery).
  • Right gastric artery: Supplies the lesser curvature of the stomach.
  • Hepatic artery proper: Ascends to the liver and branches into the right and left hepatic arteries, which supply their respective lobes of the liver. The right hepatic artery typically gives rise to the cystic artery, which supplies the gallbladder.

Relations

• Anteriorly: The celiac artery is covered by the peritoneum and lies beneath the diaphragm, just above the pancreas. In its course, it is surrounded by the celiac plexus, a network of autonomic nerves.
• Posteriorly: It is related to the abdominal aorta, from which it arises, and the diaphragm, specifically the crura of the diaphragm, which are muscle fibers that wrap around the aorta as it passes through the diaphragm. The celiac artery is also posteriorly related to the pancreas, which lies just below the origin of the artery.
• Laterally: To the left is the splenic artery, which courses toward the spleen, and to the right is the common hepatic artery, which supplies the liver and other associated structures. The adrenal glands and kidneys are located further lateral to the celiac artery.

Length and Diameter

The celiac artery is relatively short in length, typically measuring around 1 to 2 cm before it divides into its three branches. However, it is a large and broad artery in terms of diameter, which allows it to deliver a significant volume of blood to the upper abdominal organs. Its diameter is generally between 6 to 8 mm, making it one of the largest visceral arteries in the abdominal cavity.

Branching Pattern

The celiac artery usually follows a trifurcation pattern, meaning it divides into three main branches almost immediately after it arises from the abdominal aorta. However, there are some anatomical variations in the branching pattern of the celiac artery:

• Bifurcation: In some cases, the celiac artery may bifurcate into two primary branches, with one branch giving rise to the left gastric artery and the other branch supplying both the splenic and common hepatic arteries.
• Additional branches: Occasionally, small arteries such as the inferior phrenic arteries may arise directly from the celiac artery instead of the abdominal aorta, supplying the diaphragm.

Anatomical Variations

Anatomical variations of the celiac artery are relatively common. Some notable variations include:

• Hepatosplenic trunk: In this variation, the celiac artery bifurcates into two branches—one supplies the liver and spleen, while the left gastric artery arises directly from the aorta.
• Celiacomesenteric trunk: In rare cases, the celiac trunk and the superior mesenteric artery arise from a common origin.
• Aberrant branches: In some individuals, the celiac artery may give rise to additional or aberrant branches that supply nearby organs, including the diaphragm or adrenal glands.

These variations are important in clinical practice, especially during surgical procedures or imaging studies of the upper abdomen.

Termination

The celiac artery terminates by dividing into its three main branches: the left gastric artery, the splenic artery, and the common hepatic artery. These branches then continue their respective courses to supply the stomach, spleen, liver, pancreas, and portions of the duodenum.

Blood Supply Regions

The celiac artery and its branches are responsible for supplying blood to several vital abdominal organs, including:

• The stomach via the left gastric, right gastric, right gastroepiploic, and left gastroepiploic arteries.
• The spleen via the splenic artery.
• The liver via the hepatic artery proper.
• The pancreas via the pancreatic branches of the splenic artery and the superior pancreaticoduodenal artery.
• The duodenum via the gastroduodenal artery and its branches.
• The gallbladder via the cystic artery (branch of the right hepatic artery).

Function

The celiac artery, also known as the celiac trunk, plays a crucial role in supplying oxygenated blood to several vital abdominal organs, including the liver, stomach, spleen, pancreas, and portions of the small intestine. Through its branches, the celiac artery ensures that these organs receive the oxygen and nutrients they need to perform their essential digestive, metabolic, and immune functions. Below is a detailed breakdown of the specific functions of the celiac artery based on the regions it supplies.

Blood Supply to the Stomach

The celiac artery supplies the stomach through its branches, the left gastric artery, right gastric artery, right gastroepiploic artery, and left gastroepiploic artery. These arteries ensure the stomach receives a rich supply of blood to perform its digestive functions:

• Nourishment of the Gastric Mucosa: The stomach is lined with a mucosal layer that secretes gastric acid, enzymes, and mucus to aid digestion and protect the stomach lining from acidic contents. The celiac artery’s branches supply blood to the mucosal cells, ensuring they receive the oxygen and nutrients necessary for continuous acid and enzyme secretion.
• Support for Smooth Muscle Contractions (Peristalsis): The smooth muscle layers in the stomach are responsible for peristaltic movements that mix food with digestive juices and propel it toward the small intestine. The blood supply from the celiac artery ensures these muscles receive enough oxygen to perform the mechanical function of digestion efficiently.

Blood Supply to the Liver

Through its branch, the common hepatic artery, the celiac artery provides oxygenated blood to the liver, which is crucial for:

• Metabolic Function: The liver plays a key role in metabolism, including detoxification of blood, production of bile, and regulation of blood sugar. The oxygenated blood delivered by the hepatic artery proper (a continuation of the common hepatic artery) supports these vital metabolic processes.
• Bile Production: The liver produces bile, which is essential for the digestion of fats in the small intestine. The blood flow from the hepatic artery ensures the liver cells (hepatocytes) are adequately supplied with oxygen to produce bile continuously.
• Support for Liver Regeneration: The liver has a unique ability to regenerate after injury or surgery. The oxygenated blood provided by the hepatic artery aids in the process of cellular repair and regeneration.

Blood Supply to the Spleen

The splenic artery, a major branch of the celiac artery, supplies oxygenated blood to the spleen. The spleen plays a key role in immune function and blood filtration, and its blood supply is critical for:

• Immune Response: The spleen contains white blood cells, including lymphocytes and macrophages, which help detect and fight infections. The blood supplied by the splenic artery ensures that these immune cells are well-nourished and can perform their protective functions.
• Blood Filtration: The spleen filters old and damaged red blood cells from the bloodstream. The oxygenated blood from the splenic artery helps support the spleen’s filtration processes, ensuring that it can remove debris and damaged cells effectively.
• Platelet and Red Blood Cell Storage: The spleen serves as a reservoir for platelets and red blood cells. The oxygenated blood supply ensures the spleen is functioning optimally to store and release these cells as needed, especially during bleeding or injury.

Blood Supply to the Pancreas

The celiac artery supplies the pancreas, particularly the body and tail, through its splenic artery branch, while the superior pancreaticoduodenal artery (a branch of the gastroduodenal artery from the common hepatic artery) supplies the head of the pancreas. The blood supplied to the pancreas is essential for both its endocrine and exocrine functions:

• Exocrine Function: The pancreas produces digestive enzymes, including amylase, lipase, and proteases, which are secreted into the duodenum to help break down food. The oxygenated blood from the celiac artery supports the acinar cells responsible for enzyme production.
• Endocrine Function: The pancreas also produces hormones like insulin and glucagon, which regulate blood sugar levels. The blood supplied by the celiac artery ensures that the endocrine cells (Islets of Langerhans) are well-nourished and can produce and secrete these hormones effectively.

Blood Supply to the Duodenum

The gastroduodenal artery, a branch of the common hepatic artery, supplies the duodenum, the first part of the small intestine. This blood supply is critical for:

• Digestive Function: The duodenum is responsible for the initial breakdown of food as it leaves the stomach. Digestive enzymes from the pancreas and bile from the liver are mixed with food in the duodenum, and the blood supplied by the celiac artery ensures that the duodenal cells can absorb nutrients and aid in digestion.
• Mucosal Protection: The duodenum is exposed to acidic chyme from the stomach, and the mucosal lining of the duodenum produces bicarbonate to neutralize the acid. The blood flow from the gastroduodenal artery nourishes these mucosal cells, helping protect the duodenum from acid damage.

Oxygen and Nutrient Delivery

The primary function of the celiac artery is to deliver oxygen and nutrients to the organs it supplies. This function is essential for:

• Cellular Metabolism: The cells in the stomach, liver, spleen, pancreas, and duodenum rely on a continuous supply of oxygen to perform cellular respiration, which generates the energy needed for their various functions. The celiac artery ensures that these organs receive a steady flow of oxygenated blood to support their metabolic needs.
• Tissue Repair and Regeneration: The organs supplied by the celiac artery are subject to continuous wear and tear, especially during digestion. The blood flow provided by the celiac artery helps support tissue repair and regeneration, ensuring that these organs remain healthy and functional.

Role in Collateral Circulation and Anastomoses

The branches of the celiac artery form an important network of anastomoses with other major arteries, such as the superior mesenteric artery. This ensures a continuous and redundant blood supply to key organs:

• Anastomosis with the Superior Mesenteric Artery: The superior pancreaticoduodenal artery (from the celiac artery) forms an anastomosis with the inferior pancreaticoduodenal artery (from the superior mesenteric artery). This connection ensures that the pancreas and duodenum receive blood from two different sources, providing a backup in case one artery is blocked.
• Anastomosis in the Stomach: The left and right gastric arteries form an anastomosis along the lesser curvature of the stomach, while the left and right gastroepiploic arteries anastomose along the greater curvature. These anastomoses ensure that the stomach continues to receive blood even if one artery is compromised.

Clinical Significance

The celiac artery is clinically significant due to its role in supplying oxygenated blood to several vital organs, including the liver, stomach, spleen, pancreas, and parts of the duodenum. Blockage or narrowing of the celiac artery, a condition known as celiac artery stenosis, can result in reduced blood flow to these organs, potentially leading to abdominal angina or mesenteric ischemia, which causes severe abdominal pain and digestive issues.

The celiac artery is also critical in various surgical procedures, including liver transplantation, gastrectomy, and pancreaticoduodenectomy (Whipple procedure), where careful identification and preservation of the artery and its branches are crucial to avoid ischemia. Additionally, the artery can be involved in conditions such as aneurysms or compression by the median arcuate ligament, a rare disorder known as Median Arcuate Ligament Syndrome (MALS), which may cause abdominal pain and digestive disturbances. Understanding its anatomy is essential for managing vascular diseases and performing abdominal surgeries effectively.