Difference between revisions of "Category:Oesophagus - Pathology"

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Introduction

• The oesophagus is the part of alimentary tract that tends to go wrong least often.

• Failure of oesophageal function results in obstruction and in failure of ingesta to pass to the stomach.
• In the bovine there may also be failure of eructation and tympany may develop.

Defence Mechanisms

• The oesophagus has no serosa and is covered by the fibrous tissue of the neck and mediastinum, from which it derives its blood supply.
• Consequently, infection spreads easily and healing is more difficult.
• Oesophageal disease is therefore difficult to treat and is consequently very serious.

Upper Alimentary Tract Carcinoma Complex

Squamous Cell Carcinoma of Other Species

• Squamous cell carcinomas of the oesophagus are occasionally seen in other species, notably in the cat, where the tumour tends to infiltrate around the oesophageal wall resulting in a “ring carcinoma”.
• The affected cat has progressive difficulty in eating and swallowing.
• Forms part of Upper Alimentary Tract Carcinoma Complex

Traumatic Pathology

Impaction

• Commonly in cattle, horses and dogs.
• The most common sites of obstruction are the thoracic inlet, the base of the heart, and the hiatus oesophagus of the diaphragm, i.e.: the narrowest points.

Clinical Signs

Horse

• With foods that expand in oesophagus such as haylage etc.
• Also seen with whole apples.

Cattle

Impaction of a bovine oesophagus (Courtesy of Alun Williams (RVC))

• May eat a spherical object that obstructs the oesophagus mostly in anterior 1/3rd of oesophagus and can often be palpated in live animal.
• Potatoes can be a cheap source of feed and if fed whole can become stuck in oesophagus.
• If obstruction occurs further down can be difficult to diagnose and remove.
• Cattle develop bloat when oesophagus obstructed.
• Apples fairly easily to dislodge.

Dog

• Usually with small bones
• Animals that feel protective of feed may gulp food down quickly, particularly if given small chops / knuckle bones.
• Knobbly shape may make bone lodge in oesophagus, particularly just anterior to heart.
• Very difficult to dislodge (because of shape).
• Pressure necrosis occurs very quickly around it and can erode through oesophagus within about 24 hours.
• Small bone may also lodge in duodenum if they pass through the stomach.

Rupture

• Perforation may occur with sharp foreign bodies. This may lead to cellulitis or pleurisy and other complications.
• Rupture of the oesophagus admits pathogenic organisms to the mediastinum and fascial planes of the neck. Both are composed of loose connective tissue and communicate with each other.
• Infection spreads rapidly as a cellulitis, aided possibly by peristalsis and pulsation of the carotid arteries, and soon leads to pleurisy.
• Rupture is almost always fatal.

Learning Tools

Oesophagus Flashcards