Double Aortic Arch – A Case Study

Abstract

Introduction:Vascular ring is a congenital anomaly in which the trachea and esophagus (or its atretic remnant) are surrounded by vessels. Vascular rings, which constitute less than 1% of congenital heart diseases, were first identified by Gross in 1945. 1 Double aortic arch is the most frequently encountered vascular ring malformation characterized by a complete encirclement of trachea and esophagus by the aortic arch. Although the double aortic arch has various forms, the common defining feature is that both the left and right aortic arches are present. 2,3 Diagnosing DAA is challenging because it has a wide clinical spectrum. Extrinsic compression of the airway by vascular rings causes respiratory symptoms and/or feeding abnormalities that usually result in prompt diagnosis during early infancy. However, there are occasions when DAA remain undiagnosed. 4 We report a case of a middle aged man with DAA which is diagnosed after doing a CT angiogram for chronic cough and dyspnea. Case presentation:Mr. J, a 40 years old male, came to OPD with the complaints of cough and breathlessness since childhood. His mother also had dust allergy, so he was given a diagnosis of bronchial asthma. Over the time treatment with salbutamol, fluticasone, montelukast failed to benefit. When he grew older he was treated for gastro-oesophageal reflux disease resulting in no benefit. He continued to have episodes of coughing triggered by cold weather and viral respiratory infections, and was diagnosed with asthma again. His physical examination was insignificant except for tachycardia. Chest auscultation revealed no abnormality. Laboratory findings were all within the normal range. Chest radiograph showed slight tracheal compression and ECG was normal. Then Echocardiography was done showing normal features. Later Chest CT scan was advised and demonstrated compression of trachea by vascular structure consistent with anomalous arch of aorta as well as some nodular shadows in both lower lobes. To confirm the diagnosis CT angiogram was performed revealing double arch of aorta with right and left arch encircling the trachea and oesophagus. Right subclavian and right common carotid arteries arise from the right arch and left subclavian and left common carotid arteries arise from the left arch. He was referred to a cardiac surgeon. Discussion:Double aortic arch is the most common symptomatic vascular ring, accounting for 50-60 % of vascular rings. 11 Developmentally it is caused by persistence of both the right and left fourth aortic arches and the right and left dorsal aortae. 12