From the Guidelines
Truncus arteriosus can indeed cause a boot-shaped heart appearance on imaging, which is a severe congenital heart defect that requires surgical correction. In this case of an 18-week fetus with truncus arteriosus, facial dysmorphia, and negative DiGeorge testing, there was likely a possibility to carry the pregnancy to term with subsequent surgical correction of the truncus arteriosus, as truncus arteriosus is classified as a great complexity congenital heart defect according to the 2018 AHA/ACC guideline for the management of adults with congenital heart disease 1. Truncus arteriosus is a severe congenital heart defect where the aorta and pulmonary artery fail to separate during development, resulting in a single common arterial trunk. The boot-shaped appearance occurs due to right ventricular hypertrophy and abnormal cardiac orientation. Some key points to consider in the management of this condition include:
- Surgical correction typically involves separating the pulmonary arteries from the common trunk, creating a connection between the right ventricle and pulmonary arteries using a conduit, and repairing any associated defects.
- This surgery is usually performed in the first few weeks of life.
- While survival rates have improved significantly with modern surgical techniques, the presence of additional anomalies, particularly the facial dysmorphia suggesting a possible genetic syndrome even without DiGeorge syndrome, could complicate the prognosis.
- Multiple surgeries would likely be needed throughout life as the child grows, requiring conduit replacements.
- The decision to continue such a pregnancy would involve careful consideration of the complete clinical picture, including any additional anomalies not mentioned, and consultation with pediatric cardiothoracic surgeons and geneticists.
From the Research
Truncus Arteriosus and Boot-Shaped Heart
- Truncus arteriosus is a rare congenital heart defect characterized by a single arterial trunk that supplies systemic, pulmonary, and coronary circulations 2.
- The presence of a boot-shaped heart can be associated with truncus arteriosus, as seen in the fetal autopsy of an 18-week-old fetus 2.
- Facial dysmorphia, low-set ears, and retromicrognathia can be associated with truncus arteriosus, as observed in the fetus 2.
Possibility of Carrying the Baby to Term and Correcting Truncus Arteriosus
- Advances in prenatal imaging and early diagnosis have enhanced the management of truncus arteriosus, allowing for detailed planning of delivery and immediate postnatal care in specialized centers 2.
- Early surgical intervention remains crucial for improving long-term outcomes, although the condition is still associated with significant risks 2, 3.
- The intention-to-treat survival rate for neonates with truncus arteriosus can be as high as 86%, and the overall survival rate can be around 55% 2.
- However, factors such as birth weight, admit age, truncal valve surgery, and presence of genetic syndromes can affect mortality and adverse outcomes in infants undergoing truncus arteriosus repair 3, 4.
Associated Genetic Syndromes and Comorbidities
- Truncus arteriosus can be associated with genetic syndromes, such as DiGeorge syndrome, and comorbidities like prematurity and other congenital malformations 2, 5, 4.
- The presence of a 22q11 microdeletion can be identified in around 27% of tested cases with truncus arteriosus 2.
- Genetic counseling is essential in managing truncus arteriosus, given the frequent association with genetic syndromes 2, 4.