Prenatal diagnosis, associated findings and postnatal outcome of fetuses with truncus arteriosus communis (TAC)

Arch Gynecol Obstet. 2021 Aug 28. doi: 10.1007/s00404-021-06157-w. Online ahead of print.

Abstract

Purpose: To assess the spectrum of associated anomalies, the intrauterine course, postnatal outcome and management of fetuses with truncus arteriosus communis (TAC) METHODS: All cases of TAC diagnosed prenatally over a period of 8 years were retrospectively collected in two tertiary referral centers. All additional prenatal findings were assessed and correlated with the outcome. The accuracy of prenatal diagnosis was assessed.

Results: 39 cases of TAC were diagnosed prenatally. Mean gestational age at first diagnosis was 22 weeks (range, 13-38). Two cases were lost follow-up. Correct prenatal diagnosis of TAC was made in 21 of 24 (87.5%) cases and of TAC subtype in 19 of 21 (90.5%) cases. Prenatal diagnosis of TAC was incorrect in three cases: one newborn had aortic atresia with ventricular septal defect postnatally, one had hypoplastic right ventricle with dextro Transposition of the Great Arteries with coartation of the aorta and a third newborn had Tetralogy of Fallot with abnormal origin of the left pulmonary artery arising from the ascending aorta postnatally. These three cases were excluded from further analysis. In 9 of 34 (26.5%) cases, TAC was an isolated finding. 13 (38.2%) fetuses had additional chromosomal anomalies. Among them, microdeletion 22q11.2 was most common with a prevalence of 17.6% in our cohort. Another 3 fetuses were highly suspicious for non-chromosomal genetic syndromes due to their additional extra-cardiac anomalies, but molecular diagnosis could not be provided. Major cardiac and extra-cardiac anomalies occurred in 3 (8.8%) and in 20 (58.8%) cases, respectively. Predominantly, extra-cardiac anomalies occurred in association with chromosomal anomalies. Additionally, severe IUGR occurred in 6 (17.6%) cases. There were 14 terminations of pregnancy (41.2%), 1 (2.9%) intrauterine fetal death, 5 postnatal deaths (14.7%) and 14 (41.2%) infants were alive at last follow-up. Intention-to-treat survival rate was 70%. Mean follow-up among survivors was 42 months (range, 6-104). Postoperative health status among survivors was excellent in 11 (78.6%) infants, but 5 (46.2%) of them needed repeated re-interventions due to recurrent pulmonary artery or conduit stenosis. The other 3 (21.4%) survivors were significantly impaired due to non-cardiac problems.

Conclusion: TAC is a rare and complex cardiac anomaly that can be diagnosed prenatally with high precision. TAC is frequently associated with chromosomal and extra-cardiac anomalies, leading to a high intrauterine and postnatal loss rate due to terminations and perioperative mortality. Without severe extra-cardiac anomalies, postoperative short- and medium-term health status is excellent, independent of the subtype of TAC, but the prevalence of repeated interventions due to recurrent stenosis is high.

Keywords: Aortopulmonary trunk; Common arterial trunk; Congenital heart defect; Fetus; Prenatal diagnosis; TAC; Truncus arteriosus communis.