Persistent right aortic arch - thoracoscopic treatment скачать в хорошем качестве

Persistent right aortic arch - thoracoscopic treatment

Vascular ring anomalies (VRA) result from abnormal differentiation of embryonic aortic arches into the great vessels. Several types of VRAs can occur; however, persistent right aortic arch (PRAA) is the most common cause of congenital esophageal dilation in dogs and cats. This anomaly follows development of the aorta from the embryonic right 4th aortic arch, rather than the left 4th aortic arch. The esophagus becomes entrapped between the ligamentum arteriosum dorsally, pulmonary artery on the left, aorta on the right and the heart ventrally. Esophageal constriction and proximal dilation of the esophagus result. Clinical symptoms may include stunted growth despite polyphagia, postprandial regurgitation soon after weaning, and repeated episodes of aspiration pneumonia. Diagnosis of a VRA is achieved by CT. If the animal has a PRAA, radiographs will show variable dilation of the esophagus proximal to an esophageal constriction at the base of the heart. Usually, maximal dilation is observed in the cranial mediastinal area. Angiocardiography is often required for definitive diagnosis of a PRAA, but in some cases, the diagnosis can only be made by surgical exploration.