A Case of the Right Aortic Arch with Mirror-image Branching and a Left Ligamentum Arteriosum Forming a Vascular Ring

Cho, Byung Pil; Kang, Ho Suck; Yang, Young Chul; Hwang, Tae Sun; Kim, Ji Won

Abstract

We present a case of the right aortic arch with mirror image -branching and a left ligamentum arteriosum forming a vascular ring, which was found in a 59 -year -old male Korean cadaver. This anomaly is so rare that there have been only 9 cases reported in the world literatures, and ll of them were noticed through several radiological methods in infants or children showing symptoms of tracheal and/or esophageal compression. This report seems to be the first case of the anomaly which is observed by dissection of cadaver. The aortic arch was located on the right side, and the arrangement of the great vessels was the mirror image of the orientation seen with a normal left aortic arch. The descending aorta descended along the right side of the esophagus. The ligamentum arteriosum (22 mm in length; 5 mm in diameter), which persisted on the left side, connected the left pulmonary artery to the upper part of the descending aorta, passing behind the esophagus. Together with the right aortic arch, the upper part of the descending aorta, and pulmonary arteries, and the left ligamentum arteriosum formed a complete vascular ring surrounding the trachea and esophagus. However, we could not find a visible impression by the ligamentum arteriosun on the posterior wall of the esophagus. Also, the upper part of the descending aorta where the ligamentum arteriosum is attached was slightly raised, but there was not enough swelling to be judged as the aortic diverticulum. These findings suggest that there might had not been any evident clinical symptoms in this case. In addition, we could confirm that, as proposed by previous reports, this anomaly is not accompanied with any congenital heart disease in contrast to the usual right aortic arch with mirror -image branching.