Diagnostic Procedures for Esophageal Disease

The esophageal body begins at the level of the sixth cervical vertebra (C6) inferior to the cricopharyngeus muscle or upper esophageal sphincter (UES). The cricopharyngeal muscle surrounds the gullet and attaches to each side of the crico cartilage. Thus, the crico cartilage is the anterior portion of the UES and the cricopharyngeus muscle the posterior and lateral portion. At this point the esophagus is in direct apposition to the posterior wall of the trachea. The distal 4 cm of the inferior border of the esophageal body make up the lower esophageal sphincter (LES) which normally extends approximately 2 cm intra-abdominally. The esophagus enters the abdomen through the right crus of the diaphragm about the level of the tenth thoracic vertebra (T-10). The LES is a physiological landmark whose anatomical location can not be recognized grossly. The esophageal body varies in length, but on the average is 25 cm. The esophagus lies in the upper chest in the midline until it reaches the level of the carina (T-5) where it passes slightly to the right of the midline due to displacement by the aortic arch. As it descends posterior to the left atrium, it begins to deviate to the left behind the left ventricle. It passes through the diaphragm in an anterior and leftward direction. There are three areas in the esophagus where it is relatively narrow and where obstruction may occur. They are at the cricopharyngeus muscle, the carina, and the LES. The esophagus is anchored to the spine only at its upper and lower end and between these two points it is loosely attached to adjacent structures by a fibrous connective tissue.