The Pyloric Sphincteric Cylinder in Health and Disease



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Chapter 7 (page 26)


Chapter 7

Arteries, Veins, Lymphatics

Arterial Supply

The arterial supply of the stomach is derived from all three branches of the coeliac artery, which arises from the front of the aorta between the crura of the diaphragm (Last l984). It is a short wide trunk, surrounded by the coeliac lymph nodes and flanked by the coeliac ganglia of the sympathetic system.

The first branch, the left gastric artery, runs to the left, giving off an ascending oesophageal branch, and supplying the upper part of the stomach; it may also give rise to the left hepatic artery (Moore l980). It then turns downwards between the two layers of the lesser omentum, running to the right along the lesser curvature. It divides into two parallel branches, which give off branches to the anterior and posterior gastric walls and which anastomose freely with arteries from the greater curvature. The two branches of the left gastic artery then anastomose with the two branches of the right gastric artery in the region of the incisura angularis.

The second branch of the coeliac trunk, the hepatic artery, passes downwards as far as the first part of the duodenum. It then turns forwards at the opening into the lesser sac (epiploic foramen) and curves upwards into the space between the two layers of the lesser omentum towards the porta hepatis, to supply the liver. As it turns into the lesser omentum the hepatic artery gives off the gastro-duodenal and right gastric arteries. The latter passes to the left between the two layers of the lesser omentum, along the lesser curvature of the stomach, dividing into two branches which anastomose with the branches of the left gastric artery. The right gastric artery also gives off branches to the anterior and posterior gastric walls, anastomosing with branches from the right gastro- epiploic artery.

The gastro-duodenal artery passes downwards behind the first part of the duodenum, which it supplies by multiple small branches; it then divides into the superior pancreatico-duodenal artery, supplying the second part of the duodenum and head of the pancreas, and the right gastro-epiploic artery. The latter turns to the left, passes along the greater curvature of the stomach between the layers of the greater omentum, giving off branches to the anterior and posterior gastric walls. It anastomoses with the left gastro- epiploic artery at about the midportion of the greater curvature (Menguy l976).

The third branch of the coeliac trunk, the splenic artery, passes to the left along the upper border of the pancreas, behind the peritoneum and the stomach, to supply the spleen. During its course it gives off branches to the pancreas; just before entering the splenic hilum it gives off the short gastric arteries supplying the gastric fornix, and the left gastro-epiploic artery. The latter passes downwards and to the right along the greater curvature of the stomach, between the two layers of the greater omentum, to anastomose with the right gastro-epiploic artery at the midportion of the greater curvature. It gives off branches to the anterior and posterior gastric walls, which anastomose with branches of the gastric arteries along the lesser curvature. Other branches, the epiploic arteries, pass downwards between the layers of the greater omentum.

Branches from the arterial arcades on the lesser and greater curvatures ramify through the submucosa, forming a rich arterial network from which branches arise to supply the mucus membrane. Because of this arrangement the mucosa is not supplied by end arteries, with the possible exception of the mucosa along the lesser curvature, which appears to receive its arterial supply directly from branches of the right and left gastric arteries (Menguy l976).

The first 2 cm of the duodenum is supplied by multiple small branches from the hepatic and gastroduodenal arteries (Last l984). According to Cunningham (l947) the first part of the duodenum occupies the frontier zone between the coeliac and superior mesenteric vascular supplies, and the vessels which supply it vary considerably in their size and mode of origin; the peculiarity of its blood supply may partly account for the frequency with which it is the seat of ulceration.

Venous Drainage

The position of the gastric veins is similar to that of the arteries along the lesser and greater curvatures. All the gastric veins drain either directly or indirectly into the portal system, which carries venous blood to the liver.

The left gastric vein runs to the left along the lesser curvature, receiving the oesophageal veins below the oesophageal hiatus in the diaphragm. Usually it drains directly into the portal vein at the superior border of the pancreas.

The right gastric vein runs along the lesser curvature to the right, towards the pylorus, joining the portal vein behind the first part of the duodenum. It receives the prepyloric vein, a small vein running vertically across the anterior surface of the gastro-duodenal junction on the pyloric ring; it is an important visual guide to the situation of the ring (Chap. 3).

The left gastro-epiploic vein, running to the left along the greater curvature, and the short gastric veins, drain into the splenic vein or its tributaries. Having received tributaries from the pancreas as well as the inferior mesenteric vein, the splenic ultimately joins the superior mesenteric vein to form the portal vein.

The right gastro-epiploic vein runs to the right as far as the head of the pancreas. Usually it turns downwards to join the superior mesenteric vein, draining into the portal vein. Considerable variations may occur and the right gastro-epiploic may enter the portal vein directly, or it may join the splenic vein. There is no gastroduodenal vein.

The veins from the first 2 cm of the duodenum drain into the prepyloric vein (Last l984).


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