'Post-LA space index' as a potential novel marker for the prenatal diagnosis of isolated total anomalous pulmonary venous connection

New Fetal Sonographic Marker to Rule Out Total Anomalous Pulmonary Venous Return: Color Doppler Drainage From Pulmonary Vein to Atrium to Ventricle (CDDVAV)

Many cases of total anomalous pulmonary venous return (TAPVR) present with life-threatening pulmonary venous obstruction within hours following delivery. As a result, prenatal detection represents an important approach to optimizing outcome. Unfortunately, TAPVR remains one of the most challenging major forms of congenital heart disease to detect prenatally; most cases elude diagnosis until postnatal life, despite the widespread recognition of multiple fetal two-dimensional (2D) and color Doppler sonographic markers. This commentary demonstrates that even the 2D and color Doppler appearance of pulmonary venous drainage to the left atrium may be seen in cases of TAPVR. Accordingly, we describe, for the first time, a novel color Doppler fetal sonographic marker to rule out TAPVR.

Factor Analysis of the Missed Diagnosis of Total Anomalous Pulmonary Venous Connection in Prenatal Echocardiography

AIM

This study investigated the major factors contributing to the missed diagnosis of total anomalous pulmonary venous connection (TAPVC) in fetal echocardiography.

METHODS

We retrospectively analyzed the prenatal ultrasonic images of 32 fetuses with missed diagnoses of TAPVC, compared them with autopsy and postnatal surgical records, and summarized the most likely reasons leading to the missed diagnoses.

RESULTS

We studied a total of 157 fetuses with TAPVC, 32 (20.3%) of whom were missed in prenatal echocardiography. The main factors for the missed diagnoses of TAPVC in the 32 fetuses were anatomic variants leading to the formation of a false pulmonary venous horn-like structure, the combination of TAPVC with other intracardiac anomalies, difficulty or inability to show the course and abouchement of TAPVC on conventional color Doppler flow imaging (CDFI), and excessive color flow gain, with a rate of approximately 53.1% (17/32). A decreased left atrial size and augmentation of the PLAS index may be indicators of false pulmonary venous horn-like structure.

CONCLUSION

False pulmonary venous horn-like structures due to anatomic variants are a major factor in the missed diagnosis of fetal TAPVC. The presence of pulmonary venous horn-like structure in a four-chamber view does not completely exclude TAPVC.

Slow flow HD and traditional CDFI technologies in identifying pulmonary veins in the first trimester

OBJECTIVE

This study aims to assess the feasibility and effectiveness of color doppler flow imaging (CDFI) technology and the Slow Flow HD imaging technique in identifying fetal pulmonary veins (PVs) in the first trimester (11-13 + 6 weeks), and further explore the factors affecting fetal pulmonary vein identification in early pregnancy.

METHODS

Echocardiography and scanning of PVs were performed in 240 normal singleton fetuses in early pregnancy by using CDFI and slow flow HD techniques, to compare the ability of two methods to identify the PVs. Slow Flow HD technology was used to further investigate the difference of PVs identification at different gestational ages [group I (11-11 + 6 weeks), group II (12-12 + 6 weeks), group III (13-13 + 6 weeks)] and with different maternal body mass indices (BMI) (≥ 25 and < 25). In 31 cases of 240 fetuses, transvaginal ultrasonography was added due to maternal habitus or significant retroversion of the uterus, and the difference in PVs identification between transabdominal and transvaginal examination was analyzed.

RESULTS

Successful PVs identification rates via CDFI and Slow Flow HD were 32.0% and 88.3%, respectively (p < 0.05). The identification rate of at least one and two pulmonary veins in Slow Flow HD was 88.3% and 76.2%, and all four pulmonary veins in 11.6% (p < 0.05). The identification rate of group I, II and III were 76.4%, 88.9% and 96.0%, respectively. The identification rate was 45.1% in the transabdominal ultrasound group and 83.8% in the transvaginal ultrasound group. The identification rate was 62.5% in the BMI ≥ 25 group and 94.7% in the BMI < 25 group (p < 0.05).

CONCLUSIONS

Slow Flow HD can detect PVs in early pregnancy more often than using CDFI. Slow Flow HD is a feasible and effective imaging technique for evaluating PVs in early pregnancy.

Prenatal detection rates for congenital heart disease using abnormal obstetrical screening ultrasound alone as indication for fetal echocardiography

OBJECTIVE

To determine the live born prenatal detection rate of significant congenital heart disease (CHD) in a large, integrated, multi-center community-based health system using a strategy of referral only of patients with significant cardiac abnormalities on obstetrical screening ultrasound for fetal echocardiography. Detection rates were assessed for screening in both radiology and maternal fetal medicine (MFM). The impact on fetal echocardiography utilization was also assessed.

METHODS

This was a retrospective cohort study using an electronic health record, outside claims databases and chart review to determine all live births between 2016 and 2020 with postnatally confirmed sCHD that were prenatally detectable and resulted in cardiac surgery, intervention, or death within 1 year.

RESULTS

There were 214,486 pregnancies resulting in live births. Prenatally detectable significant CHD was confirmed in 294 infants. Of those 183 were detected for an overall live-born detection rate of 62%. Detection rates in MFM were 75% and in radiology were 52%. The number of fetal echocardiograms needed to detect (NND) sCHD was 7.

CONCLUSIONS

A focus on quality and standardization of obstetrical screening ultrasound with referral to fetal echocardiography for cardiac abnormalities alone achieves benchmark targets for live-born detection of significant CHD requiring fewer fetal echocardiograms.

Valley Index as a Predictor of Prenatal Diagnosis of Total Anomalous Pulmonary Venous Connection

INTRODUCTION

Total anomalous pulmonary venous connection (TAPVC) has a low prenatal diagnostic rate. Therefore, we investigated whether Doppler waveforms with a low pulsatility in the pulmonary veins can indicate fetal TAPVC.

METHODS

This retrospective study included 16 fetuses with TAPVC, including 10 with complex congenital heart disease and 104 healthy fetuses that underwent fetal echocardiography. Pulmonary venous S and D wave flow velocities and the valley (representing the lowest velocity between the S and D waves) were measured. Valley indices I and II were then calculated as (velocity of valley/greater of the S and D wave velocities) and (velocity of valley/lesser of the S and D wave velocities), respectively.

RESULTS

Supra/infracardiac TAPVC cases exhibited significantly greater valley indices than that of the healthy group. After adjusting for gestational age at fetal echocardiography, valley indices I (odds ratio [OR] 7.26, p < 0.01) and II (OR: 9.23, p < 0.01) were significant predictors of supra/infracardiac TAPVC. Furthermore, valley indices I and II exhibited a high area under the curve for detecting supra/infracardiac TAPVC, regardless of the presence of pulmonary venous obstruction.

CONCLUSION

The valley index may be a useful tool for the detection of fetal TAPVC.

Fetal left-atrial posterior-space-to-diagonal ratio at 17-37 weeks' gestation for prediction of total anomalous pulmonary venous connection

OBJECTIVES

To develop normative data for the left-atrial posterior-space-to-diagonal (LAPSD) ratio and post-left atrium space (PLAS) index in fetuses from 17 to 37 weeks' gestation, and determine the optimal cut-offs of the LAPSD ratio and PLAS index to discriminate between normal fetuses and those with total anomalous pulmonary venous connection (TAPVC).

METHODS

This was a prospective cross-sectional assessment of 428 structurally normal fetuses between 17 and 37 weeks' gestation and a retrospective study of 27 TAPVC fetuses. The fetal LAPSD ratio was calculated by dividing the left atrium-descending aorta distance (LDD) by the left atrial diagonal diameter (LA). The PLAS index was calculated as the ratio of the LDD to the descending aorta diameter (DA). Pearson's correlation analysis was used to examine the correlation of cardiac parameters with gestational age (GA) and fetal somatic growth. The PLAS index and LAPSD ratio were compared between the normal and TAPVC groups to assess their usefulness in the prenatal diagnosis of TAPVC.

RESULTS

LDD, LA and DA measures showed moderate to strong positive correlation, whereas both the LAPSD ratio and PLAS index showed a slight decrease with increasing GA and biometric variables. The fetal LAPSD ratio and PLAS index in TAPVC cases were significantly greater compared with those of fetuses with a normal heart (both P < 0.001). There were no significant differences in the PLAS index and LAPSD ratio between the isolated and complex TAPVC groups (both P = 1). No significant associations of the PLAS index and LAPSD ratio with fetal gender, four-chamber view type (apical, basal or lateral) or TAPVC type were found. Using values of ≥ 0.35 for the LAPSD ratio and of ≥ 1 for the PLAS index exhibited similar excellent diagnostic performance, with a sensitivity of 100% and specificity of 97.0% or 95.1% for detecting TAPVC.

CONCLUSIONS

Our study demonstrates that the LAPSD ratio is a practical and effective screening tool for diagnosing fetal TAPVC, similar to the PLAS index. Incorporating these parameters into routine cardiac scanning may enhance the prenatal detection of TAPVC. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Can Prenatal Diagnosis of Total Anomalous Pulmonary Venous Return (TAPVR) Using Routine Fetal Ultrasound be Improved? A Case-Control Study

Objectives

To determine the most common fetal ultrasound markers of total anomalous pulmonary venous return (TAPVR) during mid-trimester ultrasound using standardly obtained images and evaluate the performance of diagnostic algorithms for improving prenatal diagnosis.

Methods

This was a matched case-control study at a regional referral centre (2005 to 2019). Cases of TAPVR were matched to controls 1 : 4 by date of birth and biologic sex. Postprocessing review of stored fetal ultrasound images was performed by two blinded and independent observers in a standardized fashion using nine sonographic markers: (i) left/right heart disproportion; (ii) abnormal distribution of great vessels; (iii) pulmonary vein entry into the left atrium (LA); (iv) confluence behind the LA; (v) abnormal coronary sinus; (vi) absence of the Coumadin ridge; (vii) aortic diameter; (viii) distance between LA and aorta; and (ix) post-LA space index >1.27. Descriptive and inferential statistics were used to present results and compare cases and controls. Diagnostic algorithms were compared by sensitivity/specificity.

Results

21 cases of isolated TAPVR were matched to 84 controls (n = 105). The most common ultrasound marker of TAPVR was absence of pulmonary vein entry into the LA (42.9%), followed by abnormal Coumadin ridge (38.1%). Cases of TAPVR had significantly larger post-LA spaces than controls (p < 0.0001) and wider aortic diameters (p=0.006). A diagnostic algorithm stratifying on absence of pulmonary veins followed by an abnormal Coumadin ridge, can correctly identify cases of TAPVR with high specificity (90.5%) and moderate sensitivity (61.9%). Conversely, a diagnostic algorithm using the presence of any 3 abnormal markers had improved specificity (94.1%) but poorer sensitivity (23.8%).

Conclusions

Using standardly obtained images from routine fetal ultrasound, improved prenatal detection of isolated TAPVR is possible. A standardized diagnostic approach can be highly specific for fetal TAPVR, however, algorithms that are sufficiently sensitive for screening in the general population are still needed.

Diagnosis of fetal total anomalous pulmonary venous connection based on the post-left atrium space ratio using artificial intelligence

OBJECTIVE

To explore whether the post-left atrium space (PLAS) ratio would be useful for prenatal diagnosis of total anomalous pulmonary venous connection (TAPVC) using echocardiography and artificial intelligence.

METHODS

We retrospectively included 642 frames of four-chamber view from 319 fetuses (32 with TAPVC and 287 without TAPVC) in end-systolic and end-diastolic periods with multiple apex directions. The average gestational age was 25.6±2.7 weeks. No other cardiac or extracardiac malformations were observed. The dataset was divided into a training set (n=540; 48 with TAPVC and 492 without TAPVC) and test set (n=102; 20 with TAPVC and 82 without TAPVC). The PLAS ratio was defined as the ratio of the epicardium-descending aortic distance to the center of the heart-descending aortic distance. Supervised learning was used in DeepLabv3+, FastFCN, PSPNet, and DenseASPP segmentation models. The area under the curve (AUC) was used on the test set.

RESULTS

Expert annotations showed that this ratio was not related to the period or apex direction. It was higher in the TAPVC group than in the control group detected by expert and the four models. The AUC of expert annotations, DeepLabv3+, FastFCN, PSPNet, and DenseASPP were 0.977, 0.941, 0.925, 0.856, and 0.887, respectively.

CONCLUSION

Segmentation models achieve good diagnostic accuracy for TAPVC based on the PLAS ratio. This article is protected by copyright. All rights reserved.

Feasibility of Transabdominal Real-time CDFI and HDFI Techniques for Fetal Pulmonary Vein Display in the First Trimester

OBJECTIVE

This study aimed to assess the feasibility and usefulness of transabdominal color Doppler flow imaging (CDFI) technology and the high-definition flow imaging (HDFI) technique in detecting fetal pulmonary veins (PVs) in the first trimester (11-13₊₆ weeks).

METHODS

From December 2018 to October 2019, 328 pregnant women with 328 normal singleton fetuses (crown-rump length: 45-84 mm) who had undergone CDFI and HDFI scans for fetal heart and vessel examination were enrolled in this study. The cases were divided into three groups according to the gestational age: group A, 11⁺⁰ -11⁺⁶ weeks; group B, 12⁺⁰ -12⁺⁶ weeks; and group C, 13⁺⁰ -13⁺⁶ weeks. Baseline sonograms and CDFI and HDFI images were analyzed by two senior radiologists independently and blindly. The abilities of CDFI and HDFI to display PVs were compared.

RESULTS

Successful PV display rates via CDFI and HDFI were 2.3% and 68.2% (P<0.01), 22.4% and 82.4% (P<0.01), 41.5% and 91.2% (P<0.01) for group A, group B, and group C, respectively. The total successful display rates for the two methods were 28.9% (CDFI) and 84.8% (HDFI) (P<0.01).

CONCLUSIONS

The HDFI technique is more valuable than CDFI for detecting PVs in early pregnancy (11-13⁺⁶ weeks). HDFI can detect at least one PV in all cases and may be used to detect pulmonary venous anomalies early.

Post-Left Atrium Space Index in Fetuses With Total Anomalous Pulmonary Venous Connection and Other Congenital Heart Diseases

OBJECTIVES

We aimed to explore the value of the post-left atrium space (PLAS) index in the diagnosis of total anomalous pulmonary venous connection (TAPVC) and the effect of other congenital heart diseases on the PLAS index in the fetus.

METHODS

The PLAS index of 69 fetuses with TAPVC was analyzed retrospectively. Approximately 252 healthy fetuses were randomly selected as controls, and 110 cases of intracardiac malformations were randomly selected for comparison. The PLAS index was defined as the ratio of the left atrium-descending aorta distance divided by the descending aorta diameter from the 4-chamber view in the end-systolic phase.

RESULTS

There were no significant differences in the PLAS index among the 3 groups of isolated TAPVC subtypes (P > .05), or among the isolated TAPVC group and the simple and complex cardiac anomaly groups (P > .05). Compared with the control group, the PLAS index of the TAPVC group was significantly increased (P < .001). The PLAS index was significantly higher in the TAPVC group than in hypoplastic left heart syndrome, endocardial cushion defect, conotruncal defect, and ventricular septal defect groups (P < .05). The PLAS indices of the hypoplastic left heart syndrome, endocardial cushion defect, and conotruncal defect groups were all higher than that of the control group (P < .05). There was no significant difference in the PLAS index between the ventricular septal defect and control groups (P > .05).

CONCLUSIONS

The PLAS index is a sensitive parameter for the diagnosis of fetal TAPVC. There were no significant differences in the PLAS index among different TAPVC types. Complex intracardiac anomalies have an influence on the PLAS index.

Evaluation of the post-LA space index in the normal fetus

OBJECTIVE

We previously reported the post-LA space index (PLAS index), which is calculated as left atrial-descending aorta distance (LD) divided by the diameter of descending aorta (DA), could be useful for prenatal diagnosis of total anomalous pulmonary venous connection (TAPVC). In this study, we evaluated PLAS index in normal fetuses to assess its usefulness.

METHODS

In 304 normal fetuses, LD and DA were retrospectively measured, and the PLAS index was calculated. In 206 fetuses with data on the biparietal diameter (BPD) and femoral length (FL), the relationship between the PLAS index and them was investigated. We also calculated the PLAS index in 13 TAPVC fetuses.

RESULTS

Mean LD was 3.0+/-0.94 mm, mean DA was 4.8+/-0.87 mm, and the mean PLAS index was 0.62+/-0.19. DA and LD were correlated with gestational age (R = 0.52, 0.25), while the PLAS index showed little variation with gestational age (R < 0.2). BPD and FL were correlated with DA (R = 0.4, 0.42) but not with LD or the PLAS index (both R < 0.2). In the TAPVC fetuses, both LD and the PLAS index were significantly higher than in normal fetuses.

CONCLUSION

In normal fetuses, the PLAS index was independent of gestational age and fetal physique and may be useful for raising the suspicion of congenital heart disease, including TAPVC.

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.

Prenatal Diagnosis of TAPVC on Monday, Delivery of Tuesday and Cardiac Surgery at Wednesday - A Model of Perinatal Care in 3rd Trimester in Case of Fetal/Neonatal Critical Heart Defect in Tertiary Center

Total anomalous pulmonary venous connection (TAPVC) is a congenital heart defect (CHD), in which all pulmonary veins connect to the systemic veins or to the right atrium/coronary sinus instead of the left atrium. We present a case report of fetus with prenatally diagnosed isolated infracardiac type of TAPVC in 38th week of gestation. In fetal echocardiographic examination performed in the Department of Prenatal Cardiology, the fetus presented lack of visible pulmonary veins connection to left atrium, abnormal venous confluence behind left atrium, additional vein leading from abdominal cavity to mediastinum and abnormal smooth Doppler blood flow in pulmonary confluence. The accurate prenatal diagnosis allowed to deliver the neonate at term, in tertiary center one day after diagnosis, and to perform surgical reposition of pulmonary veins the following day. The neonate was referred home in a good condition after 28 days of hospitalization. This case is a good example of the value of the 3rd trimester echocardiography.

Reliability of posterior-left atrium space index measurements during 20-24 weeks of gestation in structurally normal fetuses

OBJECTIVE

We aimed to evaluate the correlation between clinical parameters and the post-left atrium (LA) space index, which is a candidate screening marker for total anomalous pulmonary venous connection (TAPVC). We also calculated the inter- and intra-observer variabilities of measurements for this parameter.

METHODS

The LA-descending aorta distance/descending aorta diameter ratios (post-LA space index) were obtained from 165 fetuses between 20 and 24 weeks of gestation. Regression analyses were utilized to evaluate the correlations across clinical parameters and the post-LA space index. Intraclass correlations coefficients were calculated for the intra- and inter-observer agreements of three examiners with different sonographic experience.

RESULTS

The mean (±SD) maternal and gestational age (GA) was 28.6±4.9 years and 21.7±0.9 weeks of gestation, respectively. In multivariate analyses, there was no correlation between post-LA space index and maternal age, fetal gender, or GA at cardiac scan. There were moderate to strong correlations across the measurements by different examiners, indicating good inter- and intra-observer agreements.

CONCLUSION

The post-LA space index during 20-24 weeks of gestation is a simple and reliable marker that is not affected by GA. However, its potential as a screening tool for TAPVC warrants further clinical investigation.

Anomalous Pulmonary Venous Return: Insights Into Prenatal Detection

OBJECTIVES

To review all cases of total anomalous pulmonary venous return (TAPVR) or partial anomalous pulmonary venous return (PAPVR) identified prenatally or postnatally at a single institution and to identify factors that may lead to a correct or missed diagnosis in both high- and low-risk fetuses on screening examinations.

METHODS

Fetal images from 16 cases of prenatally or postnatally diagnosed T/PAPVR were retrospectively reviewed to analyze factors that influenced interpretations and diagnoses.

RESULTS

Sixteen diagnoses of T/PAPVR were made, with a final number of 10 confirmed cases, 1 of which was PAPVR. Ten fetuses with a presumptive diagnosis of T/PAPVR before delivery were at an average gestational age of 24.7 weeks, with 5 cases diagnosed postnatally. None of the diagnoses of isolated TAPVR were made during a screening examination. Twelve of the pregnancies were complicated by complex cardiac defects, including 6 with heterotaxy syndromes. Of the 5 abnormal cases identified in the postpartum period, 3 had isolated TAPVR. In the 3 patients with isolated defects, prenatal echocardiography was not performed; the anatomy scan interpretations were confounded by multiple factors. In retrospect, there was no obvious sonographic evidence of TAPVR in these patients; however, color flow Doppler imaging of the pulmonary veins was not performed on any of them.

CONCLUSIONS

Although fetal echocardiography has improved the overall detection of TAPVR or PAPVR, this abnormality continues to elude prenatal diagnosis during screening in both low- and high-risk patients. We hypothesize that the use of color flow Doppler imaging in the 4-chamber view may assist in diagnosing TAPVR in screening low-risk patients, especially in those with difficult scans.