Esophagus

Front 1

What is the difference between the canine and feline esophagus?

Back 1

The muscularis is composed of striated muscle for the entire length of the esophagus in dogs, but it changes to smooth muscle in the terminal esophagus in cats.

Front 2

What is the blood supply to the esophagus?

Back 2

The main arterial blood supply to the cervical esophagus is from branches of the cranial and caudal thyroid arteries. The bronchoesophageal artery is the main source of blood for the cranial two thirds of the thoracic esophagus; the remaining thoracic esophagus is supplied by esophageal branches of the aorta or dorsal intercostal arteries. The terminal portion is supplied by a branch of the left gastric artery. The veins that drain the esophagus are largely satellites of the arteries that supply it. Veins leaving the cervical esophagus drain into the external jugular veins, and those from the thoracic esophagus drain mostly into the azygous vein. The vein that accompanies the left gastric vein drains into the portal venous system. The esophageal arteries and veins form a rich, intramural plexus of anastomosing vessels in the submucosal layer.


The blood supply to the esophagus is considered segmental, with a rich, intramural plexus of anastomosing vessels in the submucosal layer that can support long segments of the esophagus.99,158,177 Thoracic esophageal anastomoses can heal successfully after ligation of the thoracic segmental blood supply, provided the intramural vascular supply and collateral circulation from the cervical and abdominal portions of the esophagus are intact.99 Simultaneous ligation of blood vessels to the cervical and thoracic esophagus, however, results in esophageal necrosis at the thoracic inlet.99 Most cases of ischemic necrosis at the esophageal incision are associated with damage to the intramural vascular supply of the esophagus rather than the segmental vessels.41,42,99 Esophageal patching with omental pedicles or other vascularized tissues may be helpful to reinforce esophageal wounds and improve vascularity.

Front 3

How much of the cervical and thoracic esophagus can be resected?

Back 3

Resection and primary anastomoses of up to 20% of the cervical esophagus and 50% of the thoracic esophagus have been reported in experimental dogs; in clinical patients, however, resection of more than 3 to 5 cm of esophagus has been associated with an increased risk of dehiscence.

Front 4

Name the different forms of esophageal diverticula.

Back 4

Esophageal diverticula are well described in humans but are rare in dogs and cats. In humans, esophageal diverticula are categorized as congenital or acquired; acquired diverticula are further divided into pulsion and traction types. A pulsion diverticulum is an outpouching of mucosa that herniates through a defect in the tunica muscularis. It is thought to be caused by increased luminal pressure as a result of a mechanical (e.g., foreign body or stricture) or functional esophageal obstruction. In humans, pulsion diverticula are most frequently located in the pharyngoesophageal region (Zenker diverticulum) or cranial to the diaphragm (epiphrenic). A traction diverticulum is a full-thickness deviation of the esophageal wall. The term traction refers to the assumed pathogenesis, namely inflammation in an adjacent organ causing formation of an adhesion. Subsequent contraction of the adhesion pulls the esophagus outward to form a pouch. In humans, traction diverticula are most commonly found in the midthoracic esophagus and are associated with inflammation of the trachea, bronchi, and hilar lymph nodes.