Retrospective prenatal diagnosis of scimitar syndrome aided by three-dimensional power Doppler imaging

STIC-HD live flow technology in the antenatal diagnosis of scimitar syndrome: A case report

Scimitar syndrome (SS) is a rare entity with an incidence of approximately 1-3 in 200 000 people. It is typically characterized by complete or partial anomalous pulmonary venous drainage from the right lung into the systemic venous circulation, most commonly the inferior vena cava (IVC). For the first time, we report the diagnosis of SS in a fetus in utero using four-dimensional (4D) spatiotemporal image correlation combined with high-definition live flow rendering mode (STIC-HD live flow).

Fetal Diagnosis of Scimitar Syndrome in the Presence of Complex Congenital Heart Disease

Fetal diagnosis of scimitar syndrome requires a high index of suspicion. We present two fetal cases of complex congenital heart disease associated with scimitar syndrome, one of them is diagnosed with scimitar syndrome in utero. We emphasize prenatal echocardiographic findings that may assist with arriving at the correct prenatal diagnosis. We also discuss potential challenges in suspecting the presence of scimitar syndrome in utero. The postnatal echocardiographic findings and course are described for both patients. We reviewed the available literature on prenatal diagnosis of scimitar syndrome in the presence of complex congenital heart disease. We describe a new association of VACTERL, imperforate anus, scimitar syndrome, and double-outlet right ventricle all on the same patient, as well as the first prenatal diagnosis of scimitar syndrome associated with hypoplastic left heart syndrome with restrictive atrial septum. Advanced imaging modalities such as a fetal lung Magnetic Resonance Imaging is suggested as a confirmatory test when scimitar syndrome is suspected in utero in the presence of complex congenital heart disease.

Prenatal Diagnosis and Outcome of Scimitar Syndrome: A Case Series of Six Patients

Scimitar syndrome is a rare disease characterized by hypoplasia of the right lung and partial anomalous pulmonary venous drainage to the inferior vena cava. All cases with a prenatal diagnosis of scimitar syndrome with or without associated malformations in an 18-year period (2000–2018) in two large tertiary referral centers (University of Bonn and University of Cologne, Germany) were retrospectively reviewed for the intrauterine course and postnatal outcome. Six cases were diagnosed in the study period. All presented with hypoplasia of the right lung, right-sided mediastinal shift, and abnormal pulmonary venous drainage to the inferior vena cava. Systemic arterial blood supply to the right lung, albeit postnatally present in all cases, could not be detected prenatally. Major associated anomalies were present in all cases and included atrial septal defect (n = 5), coarctation (n = 3), diaphragmatic hernia (n = 2), and VACTERL association (n = 1). Half of the cohort died within 6 months after birth and all three survivors suffer from long-term pulmonary sequelae. The primary hint to the prenatal diagnosis of scimitar syndrome is the abnormal position of the heart in the chest. If searched for, abnormal venous drainage can be identified prenatally and confirms the diagnosis. The prognosis depends on the presence of associated major anomalies and the need for neonatal intervention.

Prenatal diagnosis of total anomalous pulmonary venous connection: 2D and 3D echocardiographic findings

Total anomalous pulmonary venous connection (TAPVC) is a rare cyanotic congenital heart disease that accounts for less than 1% of all congenital heart diseases. TAPVC is characterized by the absence of pulmonary venous drainage into the left atrium. It is underdiagnosed in utero, with prenatal detection rates of less than 1.4%. The prenatal diagnosis of TAPVC affects the postnatal outcome, particularly in obstructive forms (critical TAPVC), since planned delivery and perinatal management are mandatory. Thus, identifying the ultrasound key markers of TAPVC is important for the prenatal diagnosis and perinatal assistance. The ventricular size discrepancy (right ventricle > left ventricle) can be a useful marker. Furthermore, the increased retroatrial distance between the left atrium and the aorta could be a diagnostic marker for prenatal TAPVC, especially when the left atrium is small. Three- (3D) and four-dimensional ultrasonography may improve the prenatal diagnosis of TAPVC. This study reviews the two (2D) and 3D ultrasonographic markers used in the antenatal diagnosis of TAPVC, with a focus on the tools that can be used by sonographers, obstetricians, and fetal medicine specialists to improve the prenatal diagnosis of TAPVC, and when to refer the case to a fetal cardiac specialist.

Prenatal diagnosis of total and partial anomalous pulmonary venous connection: multicenter cohort study and meta-analysis

OBJECTIVES

The aims of this study were to review systematically literature on and describe the sonographic features and associated anomalies of total (TAPVC) and partial (PAPVC) anomalous pulmonary venous connection and scimitar syndrome (SS).

METHODS

A retrospective cohort study was carried out of cases of TAPVC, PAPVC and SS that underwent comprehensive ultrasound examination, seen over a 20-year period at two tertiary referral centers. Assessed variables included TAPVC subtype, gestational age at diagnosis, area behind the left atrium, ventricular disproportion, vertical vein, pulmonary venous obstruction, mode of diagnosis, association with cardiac and extracardiac conditions, and pregnancy and fetoneonatal outcomes. The outcome was considered favorable if the individual was alive and well (no functional impairment from surgery or cardiac or extracardiac conditions). Cases associated with right isomerism were excluded from the analysis, as TAPVC in these cases was only one of several major cardiac anomalies affecting sonographic signs. A systematic review was performed in order to obtain a synthesis of characteristics associated with TAPVC, PAPVC and SS. The literature search of PubMed and EMBASE (1970-2016) included reviews, case series and case reports. A meta-analysis was conducted only for TAPVC. Random-effects models were used to obtain pooled estimates of the frequencies of clinical characteristics and sonographic features.

RESULTS

For TAPVC, a total of 15 studies involving 71 patients (including 13 from the current cohort study) were included in the systematic review and meta-analysis. The pooled estimate for the association of TAPVC with congenital heart disease was 28.3% (95% CI, 18.1-41.3%) and with extracardiac anomalies it was 18.5% (95% CI, 10.5-30.6%). Of TAPVC cases, obstructed venous return was observed in 34.1% (95% CI, 22.7-47.7%), a favorable outcome in 43.8% (95% CI, 24.0-65.8%), ventricular disproportion in 59.2% (95% CI, 45.1-72.0%), increased area behind the left atrium in 58.1% (95% CI, 41.1-73.5%) and a vertical vein in 59.3% (95% CI, 41.1-75.3%). Diagnosis was established by using color or power Doppler in 84.9% (95% CI, 67.3-93.9%) of cases. For SS, there were only three studies describing eight cases, to which the current study added another five. Ventricular disproportion was present in three out of nine SS cases for which data were available, but for two of these, there was a concurrent heart anomaly. Color Doppler was used for all SS diagnoses, and four-dimensional echocardiography was useful in two out of six cases in which it was used. Outcome for SS cases was generally good. For PAPVC, there were only five studies describing five cases, to which the current study added another two. Major cardiac anomalies were associated in four out of seven of these cases, and extracardiac anomalies in three out of six cases for which data were available.

CONCLUSIONS

TAPVC can be associated with other cardiac and extracardiac anomalies in a significant percentage of cases. Leading sonographic signs are ventricular disproportion, increased area behind the left atrium and the finding of a vertical vein. Color/power Doppler is the key mode for diagnosis of TAPVC. Obstructed venous return can be expected in roughly one-third of cases of TAPVC and outcome is favorable in less than half of cases. Data for SS and PAPVC are too few to synthesize. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Developmental lung malformations in children: recent advances in imaging techniques, classification system, and imaging findings

Congenital lung anomalies represent a diverse group of developmental malformations of the lung parenchyma, arterial supply, and venous drainage, which may present anywhere from the prenatal period through adulthood. It is imperative for radiologists to be aware of imaging techniques and imaging appearance of these anomalies across the pediatric age range. This review presents the spectrum of these lesions that are often encountered in daily clinical practice. Each anomaly is discussed in terms of underlying etiology, clinical presentation, and imaging characterization with emphasis on the most up-to-date research and treatment. Knowledge of these areas is essential for accurate, timely diagnosis, which aids in optimizing patient outcomes.

Eponym. Scimitar syndrome

Scimitar syndrome is a rare congenital anomaly, characterized by partial or complete anomalous pulmonary venous drainage of the right or left lung into the inferior vena cava. The syndrome is commonly associated with hypoplasia of the right lung, pulmonary sequestration, persisting left superior vena cava, and dextroposition of the heart. The pathogenesis of the syndrome is unclear, but it seems to originate from a basic developmental disorder of the entire lung bud early in embryogenesis. Two main forms of scimitar syndrome have been described. Signs and symptoms can start during infancy (infantile form) or beyond (childhood/adult form). The infantile form generally presents within the first 2 months of life with tachypnea, recurrent pneumonia, failure to thrive, and signs of heart failure. The diagnosis of scimitar syndrome is usually made based on the characteristic chest X-ray films and can be confirmed by angiography; however, it is now done mostly by transthoracic or transesophageal echocardiography, noninvasive computed tomography, or magnetic resonance angiography. Fetal echocardiography using three-dimensional power Doppler imaging permits prenatal diagnosis. Most frequently, patients are asymptomatic in the absence of associated abnormalities and can be followed conservatively. For patients with congestive heart failure, repeated pneumonia, or pulmonary-to-systemic blood flow ratios greater than 1.5 and pulmonary hypertension, it is important to reroute the anomalous right pulmonary veins and repair the associated cardiac defects in order to avoid progression to right ventricular failure. The triad of respiratory distress, right lung hypoplasia, and dextroposition of the heart should alert the clinician to think of scimitar syndrome.

Prenatal findings and differential diagnosis of scimitar syndrome and pulmonary sequestration

OBJECTIVES

Scimitar syndrome and pulmonary sequestration (PS) have overlapping features. This accounts for postnatal descriptions of a 'sequestrated lung' in scimitar-syndrome patients. We review the similarities and differences in these two conditions, and the antenatal ultrasound findings that allow correct prenatal identification and differential diagnosis.

METHODS

This was a retrospective analysis of prenatally diagnosed cases of scimitar syndrome or PS that underwent fetal echocardiography between January 1995 and November 2004.

RESULTS

There were five cases of PS and six of scimitar syndrome. Right-sided mediastinal shift (ipsilateral relative to the affected lung) was the commonest indication for referral in scimitar syndrome whereas in sequestration, referral was because of hyperechogenic lung and contralateral mediastinal shift. Lung echogenicity was normal in scimitar syndrome but focally increased in PS. Abnormal, unobstructed pulmonary venous drainage was identified prenatally in four cases of scimitar syndrome. It was normal in three fetuses with sequestration but abnormal and obstructed in the other two cases complicated by hydrothorax. Abnormal systemic arterial supply to the affected lung was easily demonstrated in all fetuses with PS, but could not be shown prenatally in scimitar-syndrome fetuses. Postnatal embolization was warranted in one case with PS and four with scimitar syndrome, one each in the neonatal period.

CONCLUSION

Prenatally, scimitar syndrome and PS are clearly distinct entities based on lung echogenicity and laterality of mediastinal shift. Hyperechogenic lung and dextrocardia indicate the possibility of PS and scimitar syndrome, respectively. Complete delineation of the vascular pattern should be attempted in all, but is more challenging in scimitar syndrome. Obstructed venous return in PS may identify fetuses at risk of developing hydrothorax.

Three-dimensional ultrasound in prenatal diagnosis

PURPOSE OF REVIEW

Several technological advances have greatly improved three-dimensional sonography, which have improved acquisition and display capabilities. This review describes these technical changes as well as current applications of 3D sonography in prenatal diagnosis.

RECENT FINDINGS

Recently published papers have emphasized the potential of getting a precise 'any plane of choice' from a three-dimensional volume, as a new way of scanning, based on the off-line analysis of a volume dataset. Surface mode has been used to demonstrate malformations and genetic diseases. The maximum rendering mode, which highlights bones, has great potential for imaging the nasal bones and the frontal bones with the metopic suture. Organ volume can be measured, but the utility of this in clinical practice remains to be determined. Three-dimensional ultrasound needs to be standardized.

SUMMARY

Three-dimensional ultrasonography is the most rapidly developing technique in fetal imaging. New features will permit the transition from the era of 'sonography in two-dimensional planes' to 'volume ultrasound'.

A review of findings in fetal cardiac section drawings: part 4: sagittal and parasagittal views

OBJECTIVE

The goal of this presentation is to review some of the common and rare fetal heart abnormalities and to provide an easy approach to these findings with schematic drawings. In this presentation, we limit the scope to the sagittal and parasagittal sections.

METHODS

Over the past 10 years, we collected cases in which the common views of the heart were abnormal and the differential diagnoses that existed for each. This presentation shows the normal sonographic sections and then variations of these sections and the associated anomalies. We used illustrative drawings to present these findings, enabling us to point out the main sonographic features of abnormalities of the heart.

RESULTS

The work reviews 7 fetal heart abnormalities in schematic drawings.

CONCLUSIONS

This short review highlights several of the anomalies that can be recognized on the common sonographic views. The drawings tend to simplify the findings but should serve as a basis for those doing fetal echocardiography when they encounter an unusual finding.

Prenatally diagnosed pulmonary atresia with ventricular septal defect: echocardiography, genetics, associated anomalies and outcome

OBJECTIVE

To assess the accuracy of prenatal diagnosis, the association with genetic and extracardiac anomalies, and outcome in fetuses with isolated pulmonary atresia with ventricular septal defect (PA-VSD).

DESIGN AND SETTING

Retrospective study in a tertiary centre for fetal cardiology.

PATIENTS AND OUTCOME MEASURES

Echocardiographic video recordings of 27 consecutive fetuses with PA-VSD were reviewed for: (1) intracardiac anatomy; (2) presence of confluence and size of the branch pulmonary arteries; (3) source of pulmonary blood supply; and (4) side of the aortic arch. Postmortem and postnatal data were added. Karyotyping was performed in 25 patients and, in 23 of these, fluorescent in situ hybridisation to identify 22q11.2 deletion.

RESULTS

PA-VSD was correctly diagnosed in 19 of 21 patients (90%) with postnatal or autopsy confirmation of diagnosis. Central pulmonary arteries were correctly identified in 79% (15/19), the source of pulmonary blood supply in 62% (13/21) and major aortopulmonary collateral arteries in 44% (4/9). Aneuploidy was detected in 4 of 25 patients (16%) and 22q11.2 deletion in 6 of 23 patients (26%). Five of 27 patients (19%) had extracardiac anomalies. Eleven pregnancies were interrupted. Eleven of 16 liveborn babies survived. Neonatal survival was 15 of 16 (94%, 95% confidence interval (CI) 70 to 100), one-year survival was 9 of 12 (75%, 95% CI 43 to 95) and two-year survival was 5 of 9 (56%, 95% CI 21 to 86).

CONCLUSION

PA-VSD can be diagnosed by fetal echocardiography with a high degree of accuracy. However, it can be difficult to determine the morphology of the central pulmonary arteries and to locate the source of pulmonary blood supply. In most liveborn infants, complete surgical repair can be achieved.

Timing of presentation and postnatal outcome of infants suspected of having coarctation of the aorta during fetal life

OBJECTIVE

To report the timing of presentation and clinical profile of a cohort of fetuses with normal main cardiac connections but fetal echocardiographic signs suggestive of coarctation of the aorta.

DESIGN

Retrospective observational study.

SETTING

Tertiary fetal and paediatric cardiology centre.

PATIENTS

Between 1 January 1998 and 31 December 2002, 174 fetuses were studied, of whom 144 infants were born alive.

MAIN OUTCOME MEASURES

Of the 144 liveborn infants, 43 had coarctation of the aorta, four had interruption of the aortic arch, and one was managed as having hypoplastic left heart syndrome. Hemianomalous pulmonary venous drainage was diagnosed in two infants. Three infants with coarctation presented late at 7-13 weeks of age, 6-12 weeks after closure of the arterial duct. Fetuses with cardiac asymmetry had a higher incidence of left superior vena cava than a control group. For fetuses with cardiac asymmetry, the incidence of left superior vena cava and ventricular septal defects was similar in infants who proved to have coarctation postnatally and in those who did not. The 30 day and one year surgical mortality of infants having repair of coarctation of the aorta was two of 41 (4.9%, 95% confidence interval (CI) 0.6 to 16.0). All cause mortality of liveborn infants with any abnormality of the aortic arch was five of 48 (10.4%, 95% CI 3.5 to 22.7) at 30 days and one year, which was heavily influenced by prematurity and extracardiac abnormalities.

CONCLUSIONS

Precise diagnosis of coarctation of the aorta during fetal life remains difficult. Coarctation of the aorta may present several weeks after closure of the arterial duct and sequential echocardiography is recommended.

New fetal cardiac imaging techniques

Rapid advances in graphics computing and micro-engineering have offered new techniques for prenatal cardiac imaging. Some of them can be non-invasively applied to both clinical and laboratory settings, including dynamic three-dimensional echocardiography, myocardial Doppler imaging, harmonic ultrasound imaging, and B-flow sonography. With clinical constraints, a few others have been mainly used in laboratories, such as endoscopic ultrasound, magnetic resonance imaging and biomicroscopy. Appropriate use and co-use of these new tools will not only provide unique information for better clinical assessment of fetal cardiac disease but also offer new ways to improved understanding of cardiovascular development and pathogenesis.

Detailed three-dimensional fetal echocardiography facilitated by an Internet link

OBJECTIVES

To assess whether a complete virtual cardiological examination can be achieved in stored three-dimensional volumes of the fetal heart, transmitted to a tertiary fetal cardiology center via the Internet.

METHODS

Thirty sequential normal singleton pregnancies were included in the study. Four cardiac volumes were acquired using a three-dimensional ultrasound system. The volumes were sent via the Internet to a tertiary fetal cardiology center, where a detailed fetal cardiac examination was attempted using the three-dimensional volumetric dataset.

RESULTS

The median gestational age was 24 (range, 22-28) weeks. A complete heart examination was accomplished in 23 of 30 cases (76.7%; 95% confidence interval, 58-90%). The four-chamber view and the cardiac situs were seen in all cases. The right ventricular outflow tract was seen in 29 (96.7%) cases and the left ventricular outflow tract in 25 (83.3%) cases. The long-axis view of the aortic arch, superior vena cava, inferior vena cava and pulmonary veins were visualized in more than 80% of cases. The mean time of volume acquisition was 9.5 (standard deviation, 2.3) min and the mean examination time by the fetal cardiologist was 17 (standard deviation, 4.8) min.

CONCLUSIONS

These preliminary results demonstrate that a three-dimensional virtual examination of the fetal heart is possible. There are limitations such as the lack of flow and functional information but complete ascertainment of the main cardiac connections was possible in the majority of cases. The use of an Internet link has major implications, particularly for situations in which the scanning center is geographically remote from the tertiary referral center.