GP25 Comparison of associations and outcomes of prenatally and postnatally diagnosed right aortic arch: south wales’ experience

Abstract

Objectives To evaluate clinical associations and outcomes of antenatally and postnatally diagnosed Right Aortic Arch (RAA) in South Wales. Methods Retrospective observational study of all RAA patients diagnosed in South Wales between 2000–2018. Results We identified 38 cases of RAA, 68.4% antenatally diagnosed and 31.6% postnatally. Following the introduction of a structured teaching programme of fetal 3 vessels trachea (3VT) views to sonographers in South Wales in 2013, the pick-up rate of antenatally diagnosed RAA has increased, from an average of 1 patient per year prior to 2013, to 9 patients in 2018. 100% of cases were diagnosed antenatally starting from 2015. 57.7% of antenatally diagnosed cases were referred specifically for RAA, and 7.7% for suspicion of abnormal arch, while 66.7% of postnatally diagnosed patients were referred for associated cardiac conditions. Two asymptomatic patients (16.7%) from the postnatal group were referred for cardiac screening after being diagnosed with DiGeorge and 1 patient (8.3%) for RAA symptoms. Associated cardiac conditions were found in 65.8%, while 32.4% had isolated RAA. The most common associated cardiac conditions were pulmonary stenosis or atresia and ventricular septal defect, at 23.7% each, followed by tetralogy of Fallot (18.4%). 3 patients (7.9%) had 22q11 microdeletion, all in the isolated group. One patient had Edwards syndrome and one patient had CHARGE syndrome (2.6%) in non-isolated group. 7 patients (18.4%) had non-cardiac conditions. The branching pattern was described in 34.2% of cases, of which 6 cases (46.15%) being RAA with mirror image branching (MIB) and 4 cases (30.76%) being RAA with aberrant left subclavian artery (ALSCA). 4 cases of MIB compared to 1 case of ALSCA had associated cardiac conditions. 81.6% of patients with RAA were asymptomatic. 6 patients (15.8%) had respiratory symptoms, of which 4 had isolated RAA, with a median age of onset of 2.2 months, and one patient (2.6%) had apnoeic episodes (on prostaglandin for pulmonary atresia). One patient from the isolated group and one patient from the associated group underwent corrective surgery for vascular ring for significant symptoms. The majority of isolated RAA (82.6%) were discharged. Conclusions 3VT view resulted in improved antenatal diagnosis of RAA. Most RAA were associated with other cardiac conditions. RAA were mostly asymptomatic, with few developing respiratory symptoms, with a median onset at 2.2 months of age.