Plate 1

The stomach has a very rich anastomotic blood supply. The largest blood supply comes from the celiac axis (1) by way of the left gastric artery (2). The blood supply to the uppermost portion, including the lower esophagus, is from a branch of the left inferior phrenic artery (3). The left gastric artery divides as it reaches the lesser curvature just below the esophagogastric junction. One branch descends anteriorly (2a) and the other branch posteriorly along the lesser curvature. There is a bare area of stomach wall, approximately 1 to 2 cm wide, between these two vessels which is not covered by peritoneum. It is necessary to ligate the left gastric artery near its point of origin above the superior surface of the pancreas in the performance of a total gastrectomy. This also applies when 70 percent or more of the stomach is to be removed. Ligation of the artery in this area is commonly done in the performance of gastric resection for malignancy so that complete removal of all lymph nodes high on the lesser curvature may be accomplished.

A lesser blood supply to the uppermost portion of the stomach arises from the short gastric vessels (4) in the gastrosplenic ligament. Several small arteries arising from branches of the splenic artery course upward toward the posterior wall of the fundus. These vessels are adequate to ensure viability of the gastric pouch following ligation of the left gastric artery as well as of the left inferior phrenic artery. If one of these vessels predominates, it is called the posterior gastric artery; its presence becomes significant in radical gastric resection. Mobilization of the spleen, following division of the splenorenal and gastrophrenic ligaments, retains the blood supply to the fundus and permits extensive mobilization at the same time. The blood supply of the remaining gastric pouch may be compromised if splenectomy becomes necessary. The body of the stomach can be mobilized toward the right and its blood supply maintained by dividing the thickened portion of the splenocolic ligament up to the region of the left gastroepiploic artery (5). Further mobilization results if the splenic flexure of the colon, as well as the transverse colon, is freed from the greater omentum. The greater curvature is ordinarily divided at a point between branches coming from the gastroepiploic vessels (5, 6) directly into the gastric wall.

The blood supply to the region of the pylorus and lesser curvature arises from the right gastric artery (7), which is a branch of the hepatic artery (8). The right gastric artery is so small that it can hardly be identified when it is ligated with the surrounding tissues in this area.

One of the larger vessels requiring ligation during gastric resection is the right gastroepiploic artery (6) as it courses to the left from beneath the pylorus. It parallels the greater curvature. The blood supply to the greater curvature also arises from the splenic artery (9) by way of the left gastroepiploic artery (5).

Relatively few key arteries need to be ligated to control the major blood supply to the pancreas. When the duodenum and head of the pancreas are to be resected, it is necessary to ligate the right gastric artery (7) and the gastroduodenal artery (10) above the superior surface of the duodenum. The possibility of damaging the middle colic vessels (11), which arise from the superior mesenteric artery and course over the head of the pancreas, must always be considered. This vessel may be adherent to the posterior wall of the antrum of the stomach, and it may course over the second part of the duodenum, especially if the hepatic flexure of the colon is anchored high in the right upper quadrant. The anterior and posterior branches of the inferior pancreaticoduodenal artery (12) are ligated close to their points of origin from the superior mesenteric artery (13). Additional branches directly to the third portion of the duodenum and upper jejunum also require ligation.

The body and tail of the pancreas can be extensively mobilized with the spleen. The splenic artery located beneath the peritoneum over the superior surface of the pancreas should be ligated near its point of origin (9). The dorsal pancreatic artery (14) arises from the splenic artery near its point of origin and courses directly into the body of the pancreas. Following removal of the spleen, the inferior surface of the body and tail of the pancreas can be easily mobilized without division of major arteries. When the body of the pancreas is divided, several arteries will require ligation. These include the inferior (transverse) pancreatic artery (15) arising from the splenic artery and the greater pancreatic artery (16).

The blood supply to the spleen is largely from the splenic artery arising from the celiac axis. Following ligation of the splenic artery, there is a rich anastomotic blood supply through the short gastric vessels (4), as well as the left gastroepiploic artery (5). The splenic artery is usually serpentine in contour as it courses along the superior surface of the pancreas just beneath the peritoneum. Following division of the gastrosplenic vessels, it is advantageous to ligate the splenic artery some distance from the hilus of the spleen. The gastric wall should not be injured during the division of the short gastric vessels high in the region of the fundus. Small blood vessels entering the tail of the pancreas require individual ligation, especially in the presence of a large spleen and accompanying induration in the region of the tail of the pancreas.

The blood supply to the gallbladder is through the cystic artery (17), which usually arises from the right hepatic artery (18). In the triangular zone bounded by the cystic duct joining the common hepatic duct and the cystic artery, Calot's triangle, there are more anatomic variations than are found in any other location. The most common variations in this zone, which is no larger than 3 cm in diameter, are related to the origin of the cystic artery. It most commonly arises from the right hepatic artery (18) after the latter vessel has passed beneath the common hepatic duct. The cystic artery may arise from the right hepatic artery more proximally and lie anterior to the common hepatic duct. Other common variations include origin of the cystic artery from the left hepatic artery (19), the common hepatic artery (8), or the gastroduodenal artery (10); additionally, these cystic arteries may have uncommon relationships to the biliary ductal system. The variations in the hepatoduodenal ligament are so numerous that nothing should be ligated or incised in this area until definite identification has been made.