Multi-Detector Row Computed Tomographic Evaluation of a Rare Type of Complete Vascular Ring: Double Aortic Arch with Atretic Left Arch Distal to the Origin of Left Subclavian Artery
The first patient was a 16-year-old girl who presented difficulty swallowing, which had persisted for 3 years. Barium esophagography () revealed posterior indentation of the middle esophagus so MDCT was arranged to delineate the anatomical details of the aortic arch.\nThe scan was done with a 40-detector-row CT scanner (Brilliance 40; Philips, Best, the Netherlands) according to a protocol published in the literature (). The scan was interpreted on a dedicated MDCT workstation (Extended Brilliance Workspace; Philips, Best, the Netherlands).\nMulti-detector row computed tomography imaging study disclosed apparent right aortic arch with ascending aorta giving origin to a left innominate artery as first branch, which was followed by right common carotid artery and right subclavian artery (RSCA), and a blind-end diverticulum arising from descending aorta (D-aorta) with tip toward the left side (). A small protruding pouch was also noted over proximal left pulmonary artery. Proximity of the small pouch over pulmonary artery, descending aortic diverticulum, and posterioinferiorly distorted LSCA on CT suggested presence of fibrous tissue connecting these three structures.\nFibrous cord between LSCA and descending aortic diverticulum was confirmed during the surgery, and thus, the double aortic arch with left arch atresia distal to the origin of LSCA (distal left arch atresia) was the final diagnosis rather than the right aortic arch with mirror branching. In addition, left ligamentum arteriosum arising from the small pouch to the fibrous cord was also noted. The surgeons transected both the fibrous cord and ligamentum arteriosum to separate the proximity. After the operation, no specific complications occurred and the patient reported that food swallowing was improved. The follow-up MDCT one year later revealed upward migration of the LSCA without inferior tethering to descending aortic diverticulum, which meant that the ring comprising the "double aortic arch" was no longer present, thereby releasing the trachea and esophagus ().