Anomalies of the aortic arch in dogs: evaluation with the use of multidetector computed tomography angiography and proposal of an extended classification scheme

Background Congenital anomalies of the aortic arch are important as they may be associated with vascular ring anomalies. The most common vascular ring anomaly in dogs is a persistent right aortic arch. However, published data of the distribution of the different types of vascular ring anomalies and other aortic arch anomalies are lacking. The objective of this retrospective descriptive study was to evaluate both the prevalence and the different types of aortic arch anomalies that can be detected using thoracic computed tomography (CT) examination. Archived thoracic CT examinations acquired between 2008 and 2020 at a single institution were retrospectively evaluated by 2 evaluators for the prevalence and type of aortic arch anomaly. Breed, age, and presenting complaint were obtained from the medical record system. Results A total of 213 CT studies were evaluated; 21 dogs (21/213, 9.9%) showed a right aortic arch and a left ligamentum arteriosum with compression of the esophagus. The following incidental additional findings were detected: aberrant left subclavian artery (17/21, 76.2%), branching from the persistent ductus arteriosus (PDA) (1/21, 4.8%), left-sided brachiocephalic trunk (3/21, 14.3%), bicarotid trunk (17/21, 81.0%), double aortic arch (1/21, 4.8%). One hundred ninety two dogs (192/213, 90.1%) showed a left aortic arch without esophageal compression. The following additional abnormalities were obtained in those dogs with left aortic arch: aberrant right subclavian artery (3/192, 1.6%) without clinical signs of esophageal compression, aberrant vessel branching from the aorta into the left caudal lung lobe (2/192, 1.0%), focal dilatation of the left or right subclavian artery (2/192, 1.0%), bicarotid trunk (1/192, 0.5%). Conclusion Similar to previous studies an aberrant left subclavian artery is the most common additional finding in dogs with persistent right aortic arch. Newly, a left-sided brachiocephalic trunk was identified in 14.3% of the dogs with a persistent right aortic arch; no additional compression was caused by the left sided brachiocephalic trunk. Similarly, aberrant right subclavian artery can be an incidental CT finding without causing compression of the esophagus.

Aortic arch uncrossing using a tracheal resection procedure

One category of vascular rings is the right aortic arch associated with the diverticulum of Kommerell from which the left subclavian artery usually originates. In some cases, the right aortic arch crosses behind the trachea and the esophagus from right to left. The trachea and esophagus are compressed by the right aortic arch, the left ligamentum, and the posterior crossing aorta, which causes the typical symptoms of noisy breathing, dyspnea on exertion, dysphagia, and frequent upper respiratory tract infections. Division of the atretic arch segment between the diverticulum of Kommerell and the left common carotid artery may relieve the symptoms temporarily but does not relieve the compression produced by this vascular abnormality. Indeed, at the age of 10 months, this patient underwent anterior arch division and posterior aortopexy via a posterolateral thoracotomy in order to relieve the compression caused by the vascular ring. Several months after the initial operation, the patient had recurrent respiratory symptoms as a result of residual vascular compression from the circumflex arch. A CT scan and airway endoscopy confirmed tracheal compression; in addition, the tracheoscopy showed tracheomalacic changes in the compressed segment of the trachea. To relieve the symptoms and the compression, we decided to resect the tracheomalacic segment of the trachea and translocate the aortic arch anterior to the trachea and esophagus.

Ebstein Anomaly and Right Aortic Arch in Patient with Charge Syndrome

Ebstein anomaly is a rare congenital heart disease characterized by a varying degree of anatomical and functional abnormalities of tricuspid valve and right ventricle. It often coexists with other congenital cardiac malformations. Up to 79–89% of patients with Ebstein anomaly have interatrial communication in the form of patent oval foramen or atrial septal defect and more than one-third has other types of cardiac malformations. Association between Ebstein anomaly and right aortic arch is extremely rare and only few cases have been described in the literature so far. Much rarer than with other cardiac malformations, Ebstein anomaly is associated with non-cardiac malformations or genetic syndromes. Several cases of association between Ebstein anomaly and Charge syndrome have been reported, nevertheless, Ebstein anomaly accounts for less than 1% of cardiac defects seen in patients with Charge syndrome. In this case report, we present a unique case of a patient with Charge syndrome where both Ebstein anomaly and right aortic arch are present. The diagnosis of Ebstein anomaly and right aortic arch was established prenatally. In the first years of life, the patient did not exhibit any remarkable symptoms. However, over time, deterioration of right ventricle function and increased tricuspid regurgitation were observed, requiring consideration of surgical treatment at the age of five. In addition, delay in physical, motor, and mental development was observed and thus, at the age of five, the patient was consulted by a medical geneticist and a gene panel to test for structural heart defects was ordered. The test showed a mutation in chromodomain helicase DNA binding protein 7 (CHD7) gene, which, along with clinical features, allowed to establish a diagnosis of Charge syndrome. To the best of the authors’ knowledge, this is the first case report of a patient with Charge syndrome, Ebstein anomaly, and right aortic arch that has been described in the literature.

Kommerell's diverticulum of retroesophageal aberrant brachiocephalic artery with right aortic arch in an adult

A retroesophageal aberrant brachiocephalic artery is a very rare congenital aortic arch anomaly. We herein presented a 29-year-old man with right aortic arch, retroesophageal aberrant left brachiocephalic artery, left ligamentum arteriosus, and absent left internal carotid artery. Graft replacement of the descending aorta and anatomical reconstruction of left brachiocephalic artery was successfully performed using a midline sternotomy approach without blood transfusion. We discuss the surgical management for Kommerell's diverticulum.

Rare Case of a Newborn with Heterotaxy Syndrome, Right Aortic Arch and an Isolated Left Brachiocephalic Artery Arising from a Left Ductus Arteriosus

Heterotaxy is an abnormal arrangement of viscera across the left-right axis of the body often associated with a variety of complex cardiac lesions. We present a case of left isomeric heterotaxy, a right aortic arch, and a left brachiocephalic artery arising from a left ductus arteriosus.