The complaints of dysphagia, odynophagia, or ingested foreign body
immediately implicate the esophagus. The esophagus also is often
the site of pathology in patients presenting with chest pain, upper
GI bleeding (see Chapter 78, Upper Gastrointestinal Bleeding), malignancy, and mediastinitis. Many diseases of
the esophagus can be evaluated over time in an outpatient setting,
but several, such as esophageal foreign body and esophageal perforation,
must be addressed emergently.
The esophagus is a muscular tube approximately 20 to 25 cm long.
The majority of the esophagus is located in the mediastinum, posterior
and slightly lateral to the trachea, with smaller cervical and abdominal
components as well, as shown in Figure 80-1.
There is an outer longitudinal muscle layer and an inner circular
muscle layer. The upper third of the esophagus is made up of striated
muscle. From the lower half down, the esophagus is all smooth muscle
(including the lower esophageal sphincter). The esophagus is lined
with stratified squamous epithelial cells that have no secretory
Anatomic relations of the esophagus (seen from the left
side). The esophagus is about 25 cm (10 in.) long. The distance
from the upper incisor teeth to the beginning of the esophagus (cricoid cartilage)
is about 15 cm (6 in.); from the upper incisors to the level of
the bronchi, 22 to 23 cm (9 in.); and to the cardia, 40 cm (16 in.).
Structures contiguous to the esophagus that affect esophageal function
Two sphincters regulate the passage of material into and out
of the esophagus. The upper esophageal sphincter prevents air from entering
the esophagus and food from refluxing out of the esophagus into
the pharynx. The lower esophageal sphincter regulates the passage
of food into the stomach and prevents stomach contents from refluxing
into the esophagus. The upper sphincter is composed primarily of
the cricopharyngeus muscle. Additional tone is variably provided
by the inferior pharyngeal constrictor muscle and the cervical esophagus.1 The
upper sphincter has a resting pressure of around 100 mm Hg. The
lower sphincter is not discretely identifiable on an anatomic basis.
The smooth muscle of the lower 1 to 2 cm of the esophagus, in combination
with the skeletal muscle of the diaphragmatic hiatus, functions
as the sphincter, with a resting pressure of 25 mm Hg. The pressure
within the resting lower sphincter is a major source of esophageal
symptoms and is discussed below under Gastroesophageal Reflux Disease.
Three major anatomic constrictions exist within the adult esophagus
and are important when there is an esophageal foreign body or food
bolus impaction: at the cricopharyngeus muscle (C6), at the level
of the aortic arch (T4), and at the gastroesophageal junction (T10
to T11). The pediatric esophagus has two additional areas of constriction:
the thoracic inlet (T1) and the tracheal bifurcation (T6). ...