Symptomatic vascular rings in adulthood: an uncommon mimic of asthma.

Symptomatic thoracic vascular rings presenting in adulthood are thought to be rare. During a 3-year time period, we diagnosed four cases of symptomatic vascular rings, which had been treated unsuccessfully for suspected asthma. Spirometry was characterized by normal forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), and FEV1/FVC, decreased peak expiratory flow (PEF), and truncation of the expiratory flow volume loop. Chest radiographs revealed a right aortic arch in each case with computed tomography (CT) or magnetic resonance imaging (MRI) confirming the diagnosis of a vascular ring. The specific abnormalities consisted of right aortic arch with mirror branching of the main arteries and persistent ligamentum arteriosum; right aortic arch with diverticulum and a fibrous embryonic left arch; right aortic arch with aberrant left subclavian artery arising from a diverticulum of Kommerell; and a right aortic arch with persistent ligamentum arteriosum. Although they are uncommon, vascular rings first presenting in adulthood as a mimic of asthma are not rare. This diagnosis should be considered in adults when abnormal truncation of the flow-volume loop occurs or when radiographic aortic arch abnormalities are found.