The Impact of Prenatal Diagnosis on Clinical Outcomes of Isolated Vascular Rings From a Statewide Paediatric Cardiology Tertiary Service

Background: Vascular rings, including right aortic arch with aberrant left subclavian artery (RAA-ALSCA), double aortic arch (DAA) and pulmonary artery sling (PAS), are congenital anomalies that may cause airway and oesophageal compression. As prenatal detection has improved, literature comparing clinical outcomes of antenatally versus postnatally diagnosed cases continues to emerge. The aim is to define a statewide tertiary paediatric institution's clinical profile and outcomes of prenatal versus postnatally diagnosed isolated vascular rings.

Method: A retrospective single-centre review of isolated RAA-ALSCA, DAA and PAS between 1 January 1999 and 31 December 2020 was conducted. Clinical characteristics, surgical and follow-up information were collected. Antenatal and postnatally diagnosed groups were compared.

Results: Out of 123 cases diagnosed with isolated vascular rings, 98 (79.7%) cases had RAA-ALSCA, 21 (17.1%) with DAA, 4 (3.3%) with PAS. The antenatal detection rate was 73.6% in the past decade; 20.3% had a genetic disorder, of which 48% had 22q11.21 microdeletion. Of prenatally diagnosed cases, 31.3% developed symptoms, commonly stridor and dysphagia, at a median age of 2.0 months (IQR 0.0-3.0), compared to a median age of diagnosis for the postnatal cohort of 9 months (IQR 1.0-40.7). Postnatally diagnosed cases were more likely to present with symptoms, primarily respiratory distress, than prenatally diagnosed cases (p=0.006). Fifty-nine (59) cases (50% antenatally diagnosed) required vascular ring division; 6.8% had residual symptoms following surgery.

Discussion: Antenatal diagnosis has improved and leads to better parental awareness and more timely, appropriate intervention. Postnatally diagnosed patients were older, more likely to be symptomatic, underwent more investigations and were commenced on more medications for symptom management prior to diagnosis. One in five cases of isolated vascular ring anomalies carried a genetic diagnosis, which has important implications on prenatal counselling and genetic testing.