First Trimester Ultrasound Diagnosis of Right Aortic Arch (RAA)

Postnatal Outcome and Associated Anomalies of Prenatally Diagnosed Right Aortic Arch with Concomitant Right Ductal Arch: A Systematic Review and Meta-Analysis

Right aortic arch presents a reported incidence of 0.1% of the general population; the aim of our study was to evaluate the risk of associated intracardiac (ICA), extracardiac (ECA), or chromosomal abnormalities in fetuses with right aortic arch (RAA) and concomitant right ductal arch (RDA). A systematic review of the literature selected 18 studies including 60 cases of RAA/RDA. A meta-analysis with a random effect model calculated for each outcome the pooled crude proportion of associated abnormal outcomes in cases of RAA/RDA and the pooled proportions and odds ratios in RAA with LDA or RDA. Quality assessment of the included studies was achieved using the NIH quality assessment tool for case series studies. RAA/RDA presents risk of associated conotruncal CHDs of about 30% and risk of 22q11 microdeletion in the region of 1%. Two-thirds of 22q11 microdeletions had concomitant thymic hypoplasia and no other chromosomal defects were described. Risks for ICA, ECA, 22q11 microdeletion, and aberrant left subclavian artery are not substantially different in RAA with right or left arterial duct. RAA increases the risk of associated cardiac defects regardless of laterality of the ductal arch. In isolated RDA/RAA cases, absolute risks of extracardiac associated problems or surgery are rather low, we would therefore recommend reassurance, particularly when the thymus and karyotype are normal.

Prenatal findings and pregnancy outcome in fetuses with right and double aortic arch. A 10-year experience at a tertiary center

OBJECTIVE

Our objective was to evaluate the accuracy of the prenatal diagnosis and the relation between the type of right aortic arch (RAA) with other intra- or extracardiac (EC) and chromosomal anomalies.

METHODS

A retrospective, observational study was conducted between 2011-2020 in a Romanian tertiary center. All RAA cases, including double aortic arch (DAA), were extracted from the databases and studied thoroughly.

RESULTS

We detected 18 RAA cases: five (27.78%) type I (mirror image, "V" type), 11 (61.12%) type II ("U" type), and two (11.10%) DAA cases. Heart anomalies were associated in 38.89% (overall), 60% (type I), 36.37% (type II), and 0% (DAA) cases. Tetralogy of Fallot represented the most prevalent cardiac malformation (in 22.23% of cases). EC anomalies were present in 44.44% of fetuses (20% of type I, 54.55% of type II, and 50% of DAA cases). Genetic abnormalities were found in 41.17% of pregnancies, with 22q11.2 deletion in 23.53%. 55.55% of the cases had a good neonatal evolution and 44.45% of the pregnancies were terminated. An overall good outcome of pregnancy was noted in 40% of type I RAA, 63.64% of type II RAA, and 50% of DAA cases. All RAA cases examined in the first trimester were correctly diagnosed.

CONCLUSIONS

RAA can be accurately diagnosed and classified by means of prenatal ultrasound since early pregnancy. A detailed anatomy scan and genetic testing, including 22q11 deletion, should be offered to all pregnancies when RAA is discovered. When isolated, RAA associates a good outcome, indifferently the anatomical type.