Short gastric arteries

The short gastric arteries are small but important branches that supply blood to the fundus and upper part of the stomach. They typically arise from the splenic artery, a branch of the celiac trunk, and are part of the extensive blood supply system to the stomach.

Location

The short gastric arteries originate from the splenic artery as it courses along the upper border of the pancreas, just before the splenic artery reaches the spleen. These arteries run through the gastrosplenic ligament, a peritoneal fold that connects the stomach to the spleen, and extend toward the upper portion of the stomach known as the fundus. Located in the upper left quadrant of the abdomen, they supply the posterior and superior aspects of the stomach, near the cardia, and often form connections with other gastric arteries, such as the left gastro-omental artery.

Structure and Anatomy

Origin

The short gastric arteries originate from the splenic artery, which itself arises from the celiac trunk, a major branch of the abdominal aorta. These arteries are generally small in size and branch off from the splenic artery as it travels toward the spleen, specifically before the splenic artery enters the splenic hilum.

Course

After originating from the splenic artery, the short gastric arteries pass through the gastrosplenic ligament, a peritoneal fold connecting the greater curvature of the stomach to the spleen. They travel superiorly and medially to supply the fundus and upper portion of the stomach. As they move toward the stomach, these arteries follow a relatively short and direct course from the splenic artery, hence their name.

Branches

The short gastric arteries typically consist of 4 to 7 small branches that travel from the splenic artery toward the fundus of the stomach. These branches are highly variable in number and size but are generally divided into several smaller vessels that provide blood to the upper part of the stomach. Unlike other major gastric arteries, the short gastric arteries do not travel along a well-defined, lengthy path; instead, they have a relatively limited distribution near the fundus of the stomach.

Anastomoses

The short gastric arteries form anastomoses with other arteries that supply the stomach, including the:

• Left Gastric Artery: The left gastric artery supplies the lesser curvature of the stomach and anastomoses with the short gastric arteries, particularly around the upper part of the stomach near the cardia.
• Left Gastro-Omental Artery: The left gastro-omental artery runs along the greater curvature of the stomach and provides branches that anastomose with the short gastric arteries, ensuring an extensive vascular supply to the fundus and upper part of the stomach.

These anastomoses play a crucial role in ensuring that the stomach has a continuous and redundant blood supply, especially in regions such as the fundus, which rely heavily on the short gastric arteries for perfusion.

Relations

• Anteriorly: The short gastric arteries are closely related to the posterior surface of the stomach, particularly the fundus and the area near the greater curvature. As they course through the gastrosplenic ligament, they are situated between the spleen and the stomach.
• Posteriorly: The short gastric arteries are in close relation to the splenic artery and the tail of the pancreas, which lies posterior to the arteries as they travel through the retroperitoneal space before entering the gastrosplenic ligament.
• Laterally: Lateral to the short gastric arteries is the spleen, to which these arteries are indirectly related through the gastrosplenic ligament.
• Medially: Medially, the arteries are related to the stomach, specifically the fundus and cardia, which they supply.

Length and Diameter

The short gastric arteries are relatively small in length and diameter compared to other gastric arteries. Their length is variable, depending on the distance from the splenic artery to the stomach, but they are typically no longer than a few centimeters. Their diameter is generally small, reflecting their role in supplying a localized area of the stomach, specifically the fundus and upper part of the greater curvature.

Termination

The short gastric arteries terminate by supplying blood to the fundus and upper part of the stomach. Their branches spread out over the surface of the stomach near the cardia and fundus, where they anastomose with other arteries such as the left gastric and left gastro-omental arteries. They deliver blood to the outer muscular layers and inner mucosal layers of the stomach in this region.

Anatomical Variations

• Number of Branches: The number of short gastric arteries varies between individuals, with some individuals having as few as three arteries, while others may have up to seven. These variations do not typically affect the overall blood supply to the stomach, as the short gastric arteries have multiple anastomotic connections.
• Point of Origin: In some individuals, the short gastric arteries may arise slightly earlier or later along the splenic artery’s course, depending on individual anatomical differences. The arteries may also have slight variations in their entry points into the stomach, depending on the orientation of the stomach and spleen.

Function

The short gastric arteries have a vital role in supplying oxygenated blood to the fundus and upper portions of the stomach. Though relatively small and limited in their distribution, their function ensures the nourishment and maintenance of the tissues in the upper gastric region, which is critical for digestion and overall gastric health. Below is a detailed explanation of the specific functions of the short gastric arteries based on the regions they supply.

Blood Supply to the Fundus of the Stomach

The primary function of the short gastric arteries is to supply blood to the fundus of the stomach, which is the upper dome-shaped region of the stomach. The fundus serves an important role in digestion, and the short gastric arteries ensure that this area receives adequate blood flow for several reasons:

• Maintaining Gastric Mucosa: The gastric mucosa in the fundus secretes mucus and bicarbonate, which protect the stomach lining from the corrosive effects of gastric acid. The short gastric arteries provide the oxygen and nutrients necessary to maintain these secretory cells and keep the mucosa healthy and functional.
• Support for Gastric Expansion: The fundus allows the stomach to expand after food intake, acting as a reservoir for swallowed air and ingested food. The smooth muscle and connective tissues in the fundus require oxygen-rich blood to maintain their elasticity and function, which the short gastric arteries supply.
• Facilitating Digestion: Though digestion primarily occurs in the lower regions of the stomach, the fundus stores food and mixes it with gastric juices. The short gastric arteries help sustain the tissue metabolism and energy needs of the smooth muscle layers involved in this process, ensuring efficient digestion.

Oxygen and Nutrient Delivery to the Stomach

The short gastric arteries are responsible for delivering oxygen and nutrients to the tissues they supply. This function is essential for:

• Cellular Metabolism: The cells of the gastric mucosa, smooth muscle, and connective tissues in the fundus rely on a continuous supply of oxygen to perform cellular respiration, which generates the energy required for their function. The blood flow provided by the short gastric arteries ensures that these tissues have the necessary energy to perform their physiological roles.
• Tissue Repair and Regeneration: The stomach lining is subject to constant wear and tear due to exposure to acidic gastric juices and mechanical stretching during digestion. The blood supply from the short gastric arteries supports the rapid repair and regeneration of the gastric mucosa, ensuring that the fundus can maintain its protective lining and digestive functions.

Support for Gastric Acid Secretion

The fundus is involved in the production of hydrochloric acid (HCl), which plays a key role in digestion. The short gastric arteries provide blood to the parietal cells within the gastric glands of the fundus, which are responsible for secreting hydrochloric acid. This blood supply ensures that:

• Hydrochloric Acid Production is Maintained: The parietal cells in the fundus need a constant supply of oxygen and nutrients to produce hydrochloric acid, which helps break down food and provides an acidic environment for enzymes like pepsin to function.
• Acid-Base Balance: By supplying blood to the gastric cells, the short gastric arteries support the production of bicarbonate, which balances the acidic environment within the stomach and protects the stomach lining from damage.

Facilitation of Peristalsis and Gastric Motility

The short gastric arteries help sustain the muscular layers of the stomach, particularly in the fundus and upper greater curvature, supporting their role in peristalsis and gastric motility:

• Peristaltic Movement: The smooth muscle of the stomach undergoes coordinated contractions (peristalsis) that mix and propel food toward the lower parts of the stomach and intestines. The short gastric arteries supply blood to these muscle layers, providing the oxygen and energy required for peristalsis.
• Storage and Mixing of Food: The fundus functions as a storage site where food is mixed with gastric juices before it moves toward the body and antrum of the stomach for further digestion. The arteries ensure that the muscle layers in the fundus have sufficient energy to perform this function, which is critical for efficient digestion.

Contribution to Gastric Anastomotic Circulation

The short gastric arteries form anastomoses with other arteries that supply the stomach, such as the left gastric artery and the left gastro-omental artery. This anastomotic network has several important roles:

• Ensuring Redundant Blood Supply: The anastomotic connections between the short gastric arteries and other gastric arteries ensure that the stomach has a continuous and reliable blood supply. If one artery becomes compromised, the anastomotic network allows blood to be delivered from other sources, protecting the stomach from ischemic damage.
• Supporting Vascular Health of the Fundus: The fundus relies heavily on the short gastric arteries for its blood supply. The anastomotic connections with the left gastric and left gastro-omental arteries provide additional vascular support, ensuring that the fundus remains well-perfused even during variations in blood flow or after surgical procedures.

Clinical Significance

The short gastric arteries are clinically significant due to their crucial role in supplying blood to the fundus and upper portions of the stomach. During splenectomy (removal of the spleen), these arteries are at risk of injury due to their close proximity to the splenic artery and the spleen, leading to potential ischemic complications in the upper stomach. Careful management of the short gastric arteries is important to prevent gastric ischemia or necrosis.

In cases of gastric surgery or trauma, such as procedures involving the greater curvature or fundus, preserving the short gastric arteries is vital to maintain adequate blood flow to the upper stomach. Damage to these arteries can result in complications such as fundal ischemia. Additionally, their small size and location within the gastrosplenic ligament make them susceptible to injury during procedures that involve the spleen or nearby structures.