Gastrostomy – Open

Divisions

The stomach begins as a dilation in the tubular embryonic foregut during the fifth week of gestation. By the seventh week, it descends, rotates, and further dilates with a disproportionate elongation of the greater curvature into its normal anatomic shape and position. Following birth, it is the most proximal abdominal organ of the alimentary tract. The most proximal region of the stomach is called the cardia , which attaches to the esophagus. Immediately proximal to the cardia is a physiologically competent lower esophageal sphincter. Distally, the pylorus connects the distal stomach (antrum) to the proximal duodenum. Although the stomach is fixed at the gastroesophageal (GE) junction and pylorus, its large midportion is mobile. The fundus represents the superiormost part of the stomach and is floppy and distensible. The stomach is bounded superiorly by the diaphragm and laterally by the spleen. The body of the stomach represents the largest portion and is also referred to as the corpus . The body also contains most of the parietal cells and is bounded on the right by the relatively straight lesser curvature and on the left by the longer greater curvature. At the angularis incisura, the lesser curvature abruptly angles to the right. It is here that the body of the stomach ends and the antrum begins. Another important anatomic angle (angle of His) is that formed by the fundus with the left margin of the esophagus ( Figure 16-1-1 ).

Most of the stomach resides within the upper abdomen. The left lateral segment of the liver covers a large portion of the stomach anteriorly. The diaphragm, chest, and abdominal wall bound the remainder of the stomach. Inferiorly, the stomach is attached to the transverse colon, spleen, caudate lobe of the liver, diaphragmatic crura, and retroperitoneal nerves and vessels. Superiorly, the GE junction is found about 2 to 3 cm below the diaphragmatic esophageal hiatus in the horizontal plane of the seventh chondrosternal articulation, a plane only slightly cephalad to that containing the pylorus. The gastrosplenic ligament attaches the proximal greater curvature to the spleen.

Blood Supply

The celiac artery provides most of the blood supply to the stomach ( Figure 16-1-2 ). There are four main arteries – the left and right gastric arteries along the lesser curvature and the left and right gastroepiploic arteries along the greater curvature. In addition, a substantial quantity of blood may be supplied to the proximal stomach by the inferior phrenic arteries and by the short gastric arteries from the spleen. The largest artery to the stomach is the left gastric artery, and it is not uncommon (15% to 20%) for an aberrant left hepatic artery to originate from it. Consequently, proximal ligation of the left gastric artery occasionally results in acute left-sided hepatic ischemia. The right gastric artery arises from the hepatic artery (or the gastroduodenal artery). The left gastroepiploic artery originates from the splenic artery and the right gastroepiploic originates from the gastroduodenal artery. The extensive anastomotic connection between these major vessels ensures that in most cases, the stomach will survive if three out of four arteries are ligated, provided that the arcades along the greater and lesser curvatures are not disturbed. In general, the veins of the stomach parallel the arteries. The left gastric (coronary) and right gastric veins usually drain into the portal vein. The right gastroepiploic vein drains into the superior mesenteric vein and the left gastroepiploic vein drains into the splenic vein.