Foramen ovale flap aneurysm in fetuses associated with and without heart defects: Prenatal diagnosis, imaging, in‐utero hemodynamics, pregnancy, and postnatal outcomes

Abstract

BackgroundIsolated redundant foramen ovale flap aneurysm (RFOA) in the absence of restrictive foramen ovale is believed to be a cause for pseudocoarctation of aorta since the impediment of blood flow to the left heart can be severe, resembling the picture of left ventricular hypoplasia with retrograde aortic flow. The primary objective of the study is to find whether RFOA is always a benign lesion. The main focus of the study is to share my experience in particular on fetuses having redundant foramen ovale flap aneurysm developing into coarctation of aorta and to study the associated factors.MethodsRetrospective study (January 2020 to June 2023). All fetuses with RFOA associated with and without congenital heart defects were included. Fetuses with restrictive foramen ovale and RFOA with single ventricle hearts were excluded. The imaging, in‐utero hemodynamics, pregnancy, and postnatal outcomes with at least 3 months follow‐up were presented.ResultsDuring the study period, a total of 1499 fetal echocardiography were performed. Twenty‐two fetuses with RFOA were included. Fourteen fetuses had isolated RFOA and eight had associated abnormalities [extracardiac (n = 5); intracardiac (n = 2), Both (n = 1)]. Genetic evaluation were performed only in fetuses with associated defects were normal. Postnatally all isolated RFOA fetuses had no aortic arch obstruction. Fetuses with associated aberrant right subclavian artery, isolated left superior vena cava, absent ductus venosus and ventricular septal defects developed aortic arch obstruction after birth. RFOA causes smallish left ventricle in fetuses with tetralogy of Fallot which recovered to normal size postnatally.ConclusionIsolated RFOA can be benign, however, if it is associated with cardiac or extracardiac anomalies predominantly resulted in aortic arch obstruction. Though it is a cause for pseudocoarctation of aorta, through postnatal reassessment of aortic arch is mandatory. Careful search for intracardiac and systemic venous anomalies is recommended. It created confusion regarding adequacy of left ventricle when associated with congenital heart defects.

Differential diagnosis in disproportion in four‐chamber view in fetus in late pregnancy—Challenging dilemma

“…25 Karmegaraj in his study proofed that redundant foramen ovale flap aneurysm can cause dynamic resistance to the blood flow through the mitral valve, creating the appearance of ventricular disproportion, with a small left ventricle suggesting CoA. 8,24 The possible reason for ventricular disproportion is dynamic obstruction of mitral inflow and obstruction of the ductus venosus-right atrium-left atrium stream resulting in significant shift of blood from the left heart to the right heart. The reduction in the degree of ventricular disproportion in the late trimester is probably due to a decrease in pulmonary vascular resistance and an increase in the proportion of pulmonary blood flow of the fetal combined cardiac output.…”

“…12 Sometimes, disproportion is normalized during pregnancy and then there is no need to further examination. 8,21 Isolated prenatal ventricular disproportion with a dominant right ventricle comprises minor postnatal cardiac malformations and does not require neonatal intervention. 1 Which in contemporary prenatal CHD classifications mean that this could be planned or level of care 3 CHD.…”

“…21 Another explanation of disproportion could be the umbilical cord wrapped around the fetal body, especially the neck and redundant foramen ovale flap aneurysm. 8,10,24 Więckowska et al conclude that the explanation of the disproportion in 4CH could be the compression of the fetal neck by the umbilical cord which result in disproportion in cardiac blood flow. 10 Umbilical cord wrapped around the fetal neck causes disturbances in the blood supply to the cerebrum.…”

“…1 Disproportion in four-chamber view (4CH) in fetal heart can have many causes and be a physiologic finding, or a symptom of functional abnormalities or congenital heart disease (CHD). [2][3][4][5][6][7][8][9][10] Disproportion is very easy to see during an ultrasound scan, but if isolated, it is sometimes difficult to differentiate its cause. Physio-…”

Three‐dimensional high‐definition live tissue virtual dissection of mirror‐image dextrocardia with thoracic‐abdominal discordance in a fetus

“…5 3D HD-live tissue rendering has a superior value in understanding complex cardiac morphology. 6 The virtual plane images given by 3D/4D STIC imaging are not generally accessible with 2D approach which helps examiner to understand, appreciate,…”