Surgical Anatomy of the Stomach: Key Concepts

The stomach is located in the upper left quadrant of the abdomen. Its anterior aspect is related to the left hepatic lobe, diaphragm, transverse colon and greater omentum. Its posterior face is related to the pancreas, spleen and splenic artery, adrenal gland, left kidney and diaphragm.

AnteriorPosteriorLeft hepatic lobePancreasDiaphragmSpleenTransverse colonLeft adrenal glandGreater omentumLeft kidney

It has an irregular shape with two curvatures: lesser curvature (right side) and greater curvature (left side). The greater omentum is inserted on the greater curvature.

Parts of the stomach

· Cardias: is the most proximal part of the stomach, adjacent to the lower esophageal sphincter. · Fundus: is the part of the stomach that is above the esophagogastric junction. · Body: between the fundus and the antrum. · Antrum: most distal part of the stomach, its limit in the lesser curvature is the incisura angularis. · Pylorus: is a sphincter that divides the stomach from the duodenum.

The stomach wall is composed of four layers: serosa, muscle layer, submucosa and mucosa.

Vascularization

The arterial vascularization to the stomach is based on the celiac trunk with three main supplies: the left gastric artery (coronary), the hepatic artery and the splenic artery. The left gastric artery, located in the lesser curvature, has anastomosis with the pyloric artery (branch of the hepatic artery) and it can give rise to a branch that transverses the lesser omentum and irrigates the left hepatic lobe. The greater curvature is irrigated by the right and left gastroepiploic arteries, being the former a branch of the hepatic artery and the latter a branch of the splenic artery.

Venous drainage

The venous web is parallel to the arterial web and drains in it majority to the portal vein although in the gastroesophageal junction the drainage may be to the vena cava through diaphragmatic veins.

Lymphatic drainage

The lymphatic drainage is originated in the deepest sector of the mucosa to create a web of interweaved in the submucosal layer and in the subserosa. There are three major drainage areas: hepatic, left gastric and splenic. Lymph nodes are divided into groups according to the Japanese classification:

GroupLocation1Right paracardial2Left paracardial3Lesser curvaturel4Greater curvature5Suprapyloric6Infrapyloric7Left gastric artery8Common hepatic artery9Celiac trunk10Splenic hilium11Splenic artery12Hepatic hilium13Posterior duodenopancreas14Superior mesenteric artery15Middle colic artery16Paraaortic

Type of gastrectomyD1 lymphadenectomyD2 lymphadenectomyTotal1 to 6D1 + 7, 8, 9, 10*, 11, 12Distal1, 3, 4, 5, 6D1 + 7, 8, 9, 10*, 11, 12

10* the performance of the lymphadenectomy of group 10 is discretional and requires a splenectomy.

Gastric innervation

Gastric nerve supply is both sympathetic and parasympathetic. The sympathetic innervation follows the arterial supply. The parasympathetic innervation arrives to the stomach from the vagal nerves. The left vagal nerve or anterior is not always a single trunk and can be divided into three branches; immediately before the cardias it sends small branches to the fundus and through the lesser omentum it sends branches to the liver, gallbladder, pylorus and duodenum. It gives rise to the nerve of Latarjet, parallel to the lesser curvature and that ends in the “crows fool” at the level of the incisura angularis.

The posterior or right vagal nerve is usually a single trunk. Near the cardias it gives rise to a posterior and left branch called the “criminal nerve of Grassi”. The posterior Latarjet nerve descends the lesser curvature.