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

BACKGROUND

Isolated 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.

METHODS

Retrospective 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.

RESULTS

During 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.

CONCLUSION

Isolated 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.

The Predictive Value of the CSA Index in the Prenatal Diagnosis of Aortic Coarctation in Ultrasound Examination Performed during the Second Trimester

BACKGROUND

Aortic coarctation (CoA) is the fourth most common congenital heart defect (8-10%) which occurs at a frequency of about 20-60/100,000 births. Only 22.3% of all cases appears to be diagnosed during the second trimester of pregnancy. Since the detection of prenatal aortic coarctations is very low, every effort should be made to change this situation. According to the authors of this study, the CSAi (carotid to subclavian artery index) could serve as a reliable indicator.

MATERIAL AND METHODS

Ninety-six fetuses from healthy, single, pregnancies, with good ultrasound visualization between 18 and 27.5 weeks of gestation, and twenty-three fetuses suspected of aortic coarctation (postnatally confirmed) were included in this study. Our first aim was to compare the current most common method of prenatal CoA diagnosis based on the measurement of the aortic z-score in the aortic isthmus using the method suggested by us-CSAi.

RESULTS

Logistic regression coefficients for z-score and CSAi were analyzed as predictors of coarctation occurrence. It appears that 39.4% of coarctation occurrence can be predicted on the basis of the z-score, and 93.5% on the basis of the CSAi. The cut-off value for CSAi in the study group was 0.81 (sensitivity: 95.7%, specificity 99%). Based on the ROC curve analysis, the cut-off value for the carotid to subclavian distance (mm) was determined; the risk of coarctation increased above this value. Based on the Gini index (0.867), this value was set at 2.55 (sensitivity 82.6%, specificity 93.7%).

CONCLUSIONS

CSAi measurement is currently the most sensitive method for aortic coarctation detection. For the purpose of our study, this method was applied in diagnostics in the second trimester of pregnancy. This method is easy, reproducible and should be widely introduced into everyday echocardiographic diagnostics of coarctation to minimize the risk of error.

Prenatal diagnosis of coarctation of the aorta with a long and angled isthmus by two- and three-dimensional echocardiography: a case report

Background

Prenatal diagnosis of coarctation of the aorta (CoA) is challenging for most examiners. The malformation often occurs at the aortic isthmus, which is a short segment between the origin of the left subclavian artery and the insertion of the ductus. We report herein a rare case of CoA with a long, angled, and hypoplastic isthmus. The echocardiographic characteristics and postmortem findings are presented to approach the skill of fetal diagnosis.

Case presentation

A pregnant women undergone fetal echocardiography at 26 + 3 gestational weeks in our center. Conventional two-dimensional echocardiography (2DE) showed that ascending aorta went straight upward branching three brachiocephalic arteries without the appearance of the arch, suggesting the possibility of an interrupted aortic arch. Three-dimensional echocardiography (3DE) using spatiotemporal image correlation (STIC) and high-definition flow imaging technique was performed to obtain the 3D rendered images, which clearly showed the arch and its angled junction with the slim isthmus in space. Intra-uterine fetal death occurred and an autopsy was performed. The gross findings showed the angled hypoplastic aortic isthmus in detail and thus confirmed the prenatal diagnosis.

Conclusions

Traditional 2DE may be limited in showing the angled hypoplastic aortic isthmus, while the 3DE STIC technique can provide additional spatial information to show great arteries in detail, help to find tiny vessels, and thus benefit the examiners to make an accurate diagnosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-01987-7.