Читать книгу Small Animal Surgical Emergencies - Группа авторов - Страница 149

The presence of an esophageal foreign body provokes persistent waves of peristalsis. Over time, peristaltic activity weakens and there is a reduction in lower esophageal sphincter tone, which predisposes the animal to reflux esophagitis. This reflux further inflames the esophagus and a vicious circle is established. Repeated peristaltic waves crossing the foreign body itself create pressure necrosis of, respectively, mucosal, submucosal, and muscular layers. Esophageal inflammation is thought to further lower muscle tone at the cardia while mural swelling results in a yet tighter engagement of the esophageal wall around the luminal object. Certain cases undergo full‐thickness wall perforation. This can result from sharp protrusions of the foreign body or from pressure necrosis of the juxtaposed esophageal wall.

Figure 4.1 Typical obstruction sites for bulky (bone) foreign bodies.

Figure 4.2 Radiograph of an osseous foreign body within a dog's caudal thoracic (epiphrenic) esophagus. FB, foreign body.