Prenatal diagnosis (fetal ultrasound): Today the diagnosis of<unk>  can be obtained in-utero in experienced centers. Scheduled repair soon after birth in symptomatic patients can relieve tracheal compression early and therefore potentially prevent the development of severe tracheomalacia. Chest X-ray: Plain chest x-rays of patients with<unk>  may appear normal (often) or show a dominant right<unk>  arch or two<unk>  arches . There might be evidence of tracheal deviation and/or compression. Sometimes patients present with radiologic findings of pneumonia. Barium swallow (esophagraphy): Historically the esophagram used to be the gold standard for diagnosis of<unk> . In patients with<unk>  the esophagus shows left- and right-sided indentations from the vascular compression. Due to the blood-pressure related movement of the aorta and the two arches, moving images of the barium-filled esophagus can demonstrate the typical pulsatile nature of the obstruction. The indentation from a dominant right arch is usually deeper and higher compared to the dent from the left arch. Bronchoscopy: Although bronchoscopy is not routinely done in patients with suspected or confirmed<unk> , it can visualize sites and severity of pulsatile tracheal compression. Echocardiography: In babies under the age of 12 months, echocardiography is considered to be sensitive and specific in making the diagnosis of<unk>  when both arches are open. Non-perfused elements of other types of vascular rings (e.g. left arch with atretic (closed) end) or the ligamentum arteriosum might be difficult to visualize by echocardiography. Computed tomography (CT): Computed tomography after application of contrast media is usually diagnostically accurate. It shows the relationship of the arches to the trachea and bronchi. Magnetic resonance imaging (MRI): Magnetic resonance imaging provides excellent images of the trachea and surrounding vascular structures and has the advantage of not using radiation for imaging compared to Computed tomography. Cardiac catherization/aortography: Today patients with<unk>  usually only undergo cardiac catherization to evaluate the hemodynamics and anatomy of associated congenital cardiac defects. Through a catheter in the ascending aorta contrast media is injected and the resulting aortography may be used to delineate the anatomy of the<unk>  including sites of narrowing in the left<unk>  arch. Aortography can also be used to visualize the origin of all head and arm vessels originating from the two arches. Classification<unk>  is a subtype of complete vascular ring. There are three types of<unk> : * Right dominant arch (about 70% of surgical cases) * Balanced or codominant (about 5%): both arches are of equal size * Left dominant (about 25%)<unk>  with right dominant arch: Normally there is only one (left)<unk>  arch. In patients with<unk>  the ascending aorta arises normally from the left ventricle but then divides into two arches, a left and a right<unk>  arch which join posteriorly to become the descending aorta. The smaller left arch passes anteriorly and to the left of the trachea in the usual position. It is often joined by the ligamentum arteriosum (or patent ductus arteriosus) where it forms the descending aorta. The left arch gives first origin to the left common carotid artery and then the left subclavian artery. The right<unk>  arch is completing the vascular ring by passing to the right and then behind the esophagus and trachea to join the usually left-sided descending aorta. The first vessel coming off the right arch is usually the right common carotid artery followed by the right subclavian artery.<unk>  with left dominant arch: In this less common condition, as the name indicates, the left arch is the larger of the two<unk>  arches. The origins of the arm and head vessels are identical to the anatomy of<unk>  with right dominant arch Balanced or codominant<unk> : In this rare condition both<unk>  arches are of the same diameter.
Double aortic arch
Interrupted aortic arch
First arch syndrome
Right-sided aortic arch
Pulmonary atresia
Tricuspid atresia
Situs ambiguus
Double inlet left ventricle