A review of findings in fetal cardiac section drawings. Part 3: the 3-vessel-trachea view and variants

The Fetal 3-Vessel Views: An Illustrative Case-Based Tutorial

In 2018, the American Institute of Ultrasound in Medicine revised its obstetric Practice Parameter for the second-trimester fetal anatomic survey. The 2018 Practice Parameter recommends incorporation of the 3-vessel view and 3-vessel and trachea view "if technically feasible." Sonographers and other medical providers may require additional training and education to develop greater proficiency in obtaining and interpreting these views. This pictorial essay, including ultrasound images alongside their respective schematic diagrams, provides an up-to-date, practical, and clinically oriented review of the 3-vessel view and 3-vessel and trachea view and their most common presentations in the context of congenital heart disease.

Detailed Fetal Anatomic Ultrasound Examination: Effect of the 2014 Consensus Report on a Tertiary Referral Center

This study evaluates the impact of extended cardiac views on examination time, repeat imaging, and anomaly detection before and after implementation of 76811 guidelines (American Institute of Ultrasound in Medicine Consensus 2014). It is a retrospective study of singleton pregnancies undergoing detailed ultrasound imaging at 18 weeks' gestation or greater before and after the protocol change in an academic, tertiary care fetal center. Views required prior to 2014: 4-chamber, left outflow tract, right outflow tract. Additional views required after 2014: bicaval, aortic arch, 3-vessel, and 3-vessel trachea. Fetuses with known anomalies were excluded. Rates of detection of congenital heart disease (CHD), examination completion, repeat examination recommendation, fetal echocardiogram recommendation, completion by body mass index, and cardiac examination time were determined. Six hundred twenty-four subjects were included, 217 before and 407 after protocol change. Views obtained were as stated in the American Institute of Ultrasound in Medicine/Society for Maternal-Fetal Medicine consensus. Detection of CHD was not improved. Examination times increased by 20% (6.4 vs 7.7 minutes, P < 0.05). Number of incomplete studies increased by 130% (11% to 26%, P < 0.05). Twice as many patients were referred for repeat examination (6% vs 13%, P < 0.05). Completion rates were negatively correlated with body mass index. Recommendations for fetal echocardiogram were unchanged (5% vs 6%, P = 0.6). Additional imaging did not increase detection rate of CHD (3% vs 2%, P = 0.3). Extended cardiac views resulted in increased examination time, more incomplete examinations, and more repeat examinations without changing detection rates of CHD.

Two- and four-dimensional echocardiography with high-definition flow imaging and spatiotemporal image correlation in the diagnosis of fetal isolated partial anomalous pulmonary venous connection

Partial anomalous pulmonary venous connection (PAPVC) is a rare malformation. We describe a case of PAPVC, in which the left pulmonary veins coursed to the left innominate vein through a vertical vein and finally drained into the right superior vena cava; the right pulmonary veins were connected to the left atrium. Tracing the origin and destination of abnormal vessels presented at the three-vessel and trachea view is useful for the diagnosis. Four-dimensional echocardiography with high-definition flow imaging and spatiotemporal image correlation facilitates the identification of the drainage of fetal pulmonary veins, which should be considered as a complementary modality in obstetric ultrasonic examination when cardiac abnormalities are suspected.

Identification of fetal cardiac anatomy and hemodynamics: a novel enhanced screening protocol

Background

Prenatal cardiac screening is of great importance as it contributes to appropriate neonatal management and helps parents to make a decision regarding their pregnancy. The aim of our study was to evaluate the efficiency of a newly proposed screening protocol in the detection of fetal congenital heart disease (CHD).

Methods

This was a prospective study. A total of 52 cases of confirmed CHD fetuses and 248 cases of randomly selected normal fetuses were included in the study. Two sonographers with similar experience performed the cardiac screenings under two different protocols independently. The conventional protocol (Protocol A) paid greater attention to the four-chamber view and the outflow tract views. A 6-month training program was provided to sonographers performing scans under the new protocol (Protocol B), which emphasized systematically evaluating fetal cardiac anatomy and hemodynamics. Color Doppler was mandatory and some ultrasonic signs for special cardiac anomalies were also introduced into this protocol.

Results

Protocol B detected more cardiac anomalies than did Protocol A (96.2 % vs. 61.5 %, P < 0.01). Specifically, Protocol B was superior to Protocol A in detecting cardiac malpositions, abnormal systemic and pulmonary venous connection, right aortic arch, transposition of the great arteries, and congenital corrected transposition of the great arteries. By visualizing flow disturbance and retrograde flow with color Doppler, Protocol B was better than Protocol A in screening valvular associated malformations, such as pulmonary atresia, pulmonary stenosis, tricuspid dysplasia, etc. For the normal fetuses, Protocol B was better than Protocol A in reducing the false-positive detection of septal defects.

Conclusions

The current study introduces an enhanced protocol for fetal cardiac screening, under which the obstetric screening sonographers systematically identify fetal cardiac anatomy and hemodynamics. A short-term training program makes it possible for the screening sonographers to become familiar with the new protocol, and its value has been confirmed due to improvements made in screening efficiency.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-016-0933-9) contains supplementary material, which is available to authorized users.

Assessment of the ductus arteriosus in fetuses with tetralogy of Fallot and the implication for postnatal management

OBJECTIVE

To describe the antenatal and neonatal echocardiographic morphology and flow pattern of the ductus arteriosus in patients with tetralogy of Fallot.

PATIENTS AND METHODS

We included patients with a prenatal diagnosis of tetralogy of Fallot between January 2006 and December 2012.

RESULTS

Among the 52 fetuses with tetralogy of Fallot the severity of right ventricular outflow obstruction was considered mild in 32, moderate in 14, and severe in 6. In the mild right ventricular outflow obstruction group (n = 32) all had normal ductal morphology and flow pattern, eight (25%) elected for termination of pregnancy and two died in the neonatal period from extracardiac causes. In the moderate right ventricular outflow obstruction group (n = 14) the fetuses had a small ductus arteriosus with antegrade but abnormal flow velocity, one (7%) elected for termination of pregnancy. Immediately after birth the ductus arteriosus was very small or already closed at echocardiographic examination. Two out of 13 patients (15%) developed severe hypoxic spells and underwent modified Blalock-Taussig shunt during the neonatal period. Six fetuses were considered to have severe right ventricular outflow obstruction with flow reversal in the ductus arteriosus, three (50%) of whom elected for termination of pregnancy. The other three newborns underwent modified Blalock-Taussig shunt.

CONCLUSION

In fetuses with tetralogy of Fallot, ductal diameter can be reduced even up to prenatal closure. Prenatal ductal morphology assessment may be useful for improving management of patients with moderate right ventricular outflow obstruction and small ductus arteriosus who may become cyanotic at birth.

Rightward convexity of the great vessel arising from the anterior ventricle: a novel fetal marker for transposition of the great arteries

OBJECTIVES

Traditionally transposition of the great arteries (TGA) is suggested by bifurcation of the great vessel arising from the posterior ventricle and the parallel course of the great vessels as they leave the heart. These findings may be difficult to demonstrate, requiring additional fetal echocardiographic features to indicate TGA. In this study, we investigated a new marker of TGA, namely rightward convexity of the great vessel arising from the anterior ventricle.

METHODS

We reviewed fetal studies from 2006 to 2010 in which an antenatal diagnosis of TGA was confirmed postnatally. We specifically viewed images obtained by scanning the great vessel arising from the anterior ventricle cranially to the superior mediastinum at the level of the three vessels and trachea view and compared them with similar views in normal hearts.

RESULTS

In 21 cases of confirmed TGA, the great vessel arising from the anterior ventricle (aorta) coursing cranially demonstrated an abnormal convexity to the right. This was in contrast to convexity to the left or lack of convexity of the great vessel (pulmonary artery) arising from the anterior ventricle in fetuses with a normal heart. In two fetuses rightward vessel convexity from the anterior ventricle was the clue on the initial scan suggesting TGA, which was subsequently confirmed. In addition, only two vessels, the superior vena cava and aorta, were demonstrated in fetuses with TGA, the pulmonary artery and ductus arteriosus lying below (caudal to) the transverse arch.

CONCLUSIONS

Noting the rightward convexity of the great vessel arising from the anterior ventricle may aid in the prenatal diagnosis of TGA. Furthermore, the relative simplicity of this sign may make it valuable in fetal screening for this cardiac defect.

Application of the 3-vessel view in routine prenatal sonographic screening for congenital heart disease

OBJECTIVES

The purpose of this study was to evaluate the diagnostic accuracy of prenatal screening for congenital heart disease (CHD) based on a combination of the 4-chamber view and 3-vessel view in an unselected population.

METHODS

A prospective study on 8025 scanned fetuses was performed. All singleton pregnancies scheduled for routine prenatal sonographic screening at 20 to 24 weeks' gestation and subsequently delivered in our unit were included. Data were recorded regarding visualization of the 4-chamber view, outflow tracts, and 3-vessel view. Suspected CHD was confirmed by postmortem or postnatal echocardiography. We obtained follow-up data for the neonates and calculated the diagnostic accuracy of the examinations.

RESULTS

Major CHD was identified in 32 cases (4.0%), of which 26 (81.3%) were diagnosed antenatally and 6 (18.7%) postnatally. Four cases (0.5%) had false-positive findings. Twenty-one cases were identified by the 4-chamber view and 5 by an abnormal 3-vessel view. The sensitivity of the 4-chamber view alone was 65.6%, and the specificity was 99.9%. The sensitivity of the combination of the 4-chamber view and 3-vessel view was 81.3%, and the specificity was 99.9%.

CONCLUSIONS

The 3-vessel view is a reliable and easy method to be used in a routine antenatal clinic along with the 4-chamber view.

Prenatal diagnosis and outcome of isolated vascular rings

The purpose of this study was to describe our experience in the ultrasound visualization and management of prenatally diagnosed isolated vascular rings. From January 2002 to December 2007, a total of 19 fetuses had a sonographic diagnosis of isolated vascular rings in 2 reference centers at a mean gestational age of 23 weeks. There were 8 cases of left aortic arch with aberrant right subclavian artery, 5 cases of double aortic arch, and 6 cases of right aortic arch with aberrant left subclavian artery. Two fetuses had associated trisomy 21 and 1 had a 22q11 microdeletion. Parents chose to terminate the pregnancy in all cases. Four patients successfully underwent surgical correction, and in 1 patient, tracheoplasty was also performed. In conclusion, isolated vascular rings can be accurately diagnosed prenatally by using the "3-vessel and trachea view" and "supra-aortic-branch view" that allow detection of vascular structures running around the trachea. Karyotyping and prenatal testing for 22q11 microdeletions should be offered to all parents. Affected children should undergo surgical correction as soon as symptoms of tracheal compression appear, avoiding tracheomalacia. Associated congenital tracheal stenosis should be excluded before surgery.