The venous blood supply of the upper abdomen parallels the arterial blood supply. The portal vein (1) is the major vessel that has the unique function of receiving venous blood from all intraperitoneal viscera with the exception of the liver. It is formed behind the head of the pancreas by the union of the superior mesenteric (2) and splenic (3) veins. It ascends posterior to the gastrohepatic ligament to enter the liver at the porta hepatis. It lies in a plane posterior to and between the hepatic artery on the left and the common bile duct on the right. This vein has surgical significance in cases of portal hypertension. When portacaval anastomosis is performed, exposure is obtained by means of an extensive Kocher maneuver. Several small veins (4) from the posterior aspect of the pancreas enter the sides of the superior mesenteric vein near the point of origin of the portal vein. Care must be taken to avoid tearing these structures during the mobilization of the vein. Once hemorrhage occurs, it is difficult to control.
The coronary (left gastric) vein (5) returns blood from the lower esophageal segment and the lesser curvature of the stomach. It runs parallel to the left gastric artery and then courses retroperitoneally downward and medially to enter the portal vein behind the pancreas. It anastomoses freely with the right gastric vein (6), and both vessels drain into the portal vein to produce a complete venous circle. It has a significance in portal hypertension in that the branches of the coronary vein, along with the short gastric veins (7), produce the varicosities in the fundus of the stomach and lower esophagus.
The other major venous channel in the area is the splenic vein (3), which lies deep and parallel to the splenic artery along the superior aspect of the pancreas. The splenic vein also receives venous drainage from the greater curvature of the stomach and the pancreas, as well as from the colon, through the inferior mesenteric vein (8). When a splenorenal shunt is performed, meticulous dissection of this vein from the pancreas with ligation of the numerous small vessels is necessary. As the dissection proceeds, the splenic vein comes into closer proximity with the left renal vein where anastomosis can be performed. The point of anastomosis is proximal to the entrance of the inferior mesenteric vein.
The venous configuration on the gastric wall is relatively constant. In performing a conservative hemigastrectomy, venous landmarks can be used to locate the proximal line of resection. On the lesser curvature of the stomach, the third branch (5a) of the coronary vein down from the esophagocardiac junction is used as a point for transection. On the greater curvature of the stomach the landmark is where the left gastroepiploic vein (9) most closely approximates the gastric wall (9a). ...