THE MESENTERY GENERAL CONSIDERATIONS

THE MESENTERY GENERAL CONSIDERATIONS

The arterial supply and venous and lymphatic drainage of each digestive organ are located in the mesentery . Thus diseases of individual organs can have significant e ff ects on the adjoining mesentery and its components. The pancreas and the e ff ects of pancreatitis are a good example. The pancreas is positioned on the mesentery ( 65.5 ). It arches are intramesenteric). The neck of the pancreas is anterior to the region of the mesentery that contains the portal vein. The body and tail of the pancreas are in the dorsal mesogastrium (i.e. the posterior wall of the upper region sack) and the tip of the tail of the pancreas is located at the hilum of the spleen (see Development of the mesentery and peritoneum ). Given these anatomical relations, acute inflammation of the pancreas can a ff ect any of these structures . Complications of acute pancreatitis thus include thrombosis in the portal and splenic vein, gastric outlet obstruction and arterial haemor - rhage (see Chapter 72 ). The mesentery is remarkably well preserved in most diseases. Although rarely encountered in clinical practice, mesenteric necrosis is mostly seen in advanced necrotising pancreatitis. Primary defects (i.e. non-sur gical causes) of the mesentery are rare. These are always accompanied by failure of normal development of the adjoining organ. For example, intestinal atresia arises when a section of the adjoining mes - entery fails to develop. The mesentery comprises adipose, connective tissue, neurological, lymphatic and vascular components. Abnormalities can arise in any of these and lead to either solid (tumour deposits, lymphatic metastases) or cystic lesions. The supportive capacity of the mesentery is reflected in the finding of splen unculi, heterotopic pancreas, ossification, teratomas and even ectopic pregnancies in di ff erent regions of the mesentery .