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The esophagus begins at the level of the caudal border of the cricoid cartilage and ends at the cardia of the stomach. It is divided into cervical, thoracic, and abdominal portions. The cervical portion inclines from a dorsal position to the left of the trachea at its origin and remains on the left side of the trachea at the thoracic inlet. The thoracic portion extends from the thoracic inlet to the esophageal hiatus of the diaphragm. At the level of the tracheal bifurcation, the esophagus crosses the trachea to regain a dorsal position. The abdominal portion of the esophagus is the wedge‐shaped terminal part. The layers of the esophagus include the mucosa, submucosa, muscularis, and adventitial layer; the esophagus lacks a serosal covering. The lack of serosal covering may contribute to incisional dehiscence following surgery. Functional sphincters are located cranially and caudally at the pharyngoesophageal and gastroesophageal junction. The blood supply to the esophagus comes from multiple sources. The cranial and caudal thyroid arteries are the main arterial blood supply to the cervical esophagus (see Chapter 29, Figure 29.4). The cranial two‐thirds of the thoracic esophagus is supplied by the bronchoesophageal artery, and the remaining portion is supplied by branches of the dorsal intercostal arteries and the aorta (see Chapter 37, Figures 37.1 and 37.2). A branch of the left gastric artery supplies the terminal portion of the esophagus.

The esophagus is constrained at certain points (Figure 4.1). The aorta and trachea limit esophageal distension overlying the heart base. The esophageal hiatus of the diaphragm and cardiac sphincter similarly restrict esophageal dilatation. The incidence of foreign body lodgment is highest in the caudal thoracic esophagus (Figure 4.2) followed by the esophageal region adjacent to the heart base [1, 2, 4], although non‐referral cases may show a wider variety in foreign body location [5]. Fishhooks and needles appear to lodge with a more even distribution along the esophagus.