Total Anomalous Pulmonary Venous Connections, Human Genetics.

Partial anomalous pulmonary venous connections (PAVC) have been found after abnormal gene expressions involving several syndromes. Total anomalous pulmonary venous connection (TAPVC) is found in conjunction with heterotaxia syndrome as well as several other syndromes. It has been reported with an autosomal dominance with variable expression and incomplete penetrance. The occurrence is also related to environmental factors which may superimpose on a familial susceptibility for TAPVC. Many pathways are involved in the normal development of the pulmonary venous connections and as a consequence disturbance of many genetic and epigenetic pathways lead to partial or total pulmonary venous misconnections. In this chapter, an overview of current knowledge regarding human genetics of anomalous venous connections is provided.

Adult Partial Anomalous Pulmonary Venous Connection: Case Reports (Including a Case of Scimitar Syndrome).

Partial anomalous pulmonary venous connection (PAPVC) is a congenital heart defect in which one or more pulmonary veins drain abnormally into the systemic venous circulation, leading to the development of pulmonary arterial hypertension. It can be supracardiac type, draining into the superior vena cava or right atrium (also called cardiac type) and infracardiac type with drainage into the inferior vena cava (IVC). We present two cases-supracardiac and infracardiac types of PAPVC in this case report.

TAPVR: Molecular Pathways and Animal Models.

The venous pole of the heart where the pulmonary veins will develop encompasses the sinus venosus and the atrium. In the fourth week of development, the sinus venosus consists of a left and a right part receiving blood from the common cardinal vein, the omphalomesenteric and umbilical veins. Asymmetrical expansion of the common atrium corresponds with a rightward shift of the connection of the sinus to the atrium. The right-sided part of the sinus venosus including its tributing cardinal veins enlarges to form the right superior and inferior vena cava that will incorporate into the right atrium. The left-sided part in human development largely obliterates and remodels to form the coronary sinus in adults. In approximately the same time window (4th-fifth weeks), a splanchnic vascular plexus surrounds the developing lung buds (putative lungs) with a twofold connection. Of note, during early developmental stages, the primary route of drainage from the pulmonary plexus is toward the systemic veins and not to the heart. After lumenization of the so-called mid-pharyngeal endothelial strand (MPES), the first anlage of the pulmonary vein, the common pulmonary vein can be observed in the dorsal mesocardium, and the primary route of drainage will gradually change toward a cardiac drainage. The splanchnic pulmonary venous connections with the systemic cardinal veins will gradually disappear during normal development. In case of absence or atresia of the MPES, the pulmonary-to-systemic connections will persist, clinically resulting in total anomalous pulmonary venous return (TAPVR). This chapter describes the developmental processes and molecular pathways underlying anomalous pulmonary venous connections.

Clinical Presentation and Therapy of Total Anomalous Pulmonary Venous Return.

Total anomalous pulmonary venous return (TAPVR) is rare (accounting for about 1% of all CHD) and can occur as a single lesion or in combination with other types of CHD (such as heterotaxy or HLHS). TAPVR is defined as an abnormal connection where all pulmonary veins do not drain into the left atrium but into the right atrium either directly or through a vein that is connected to the right atrium. TAPVR can be divided into four anatomic groups (Fig. 32.1): (1) supracardiac (about 55%), (2) cardiac (about 30%), (3) infracardiac (about 13%), and (4) mixed (very rare). In addition, it can be divided into two physiological types: nonobstructed and obstructed. Embryologically, all pulmonary veins usually connect to a pulmonary venous confluence that connects to the left atrium. If this connection does not occur, the pulmonary venous confluence connects to a systemic vein instead.

Scimitar syndrome with vein stenosis in an infant.

Scimitar syndrome is characterised by right lung hypoplasia and abnormal pulmonary venous return, known as the 'scimitar vein'. We report the case of an infant girl with scimitar syndrome who developed a severe respiratory distress mimicking asthma. Pulmonary hypertension (PH) was diagnosed, attributed to scimitar vein stenosis and a left-to-right shunt. Scimitar vein stenosis, a rare complication of scimitar syndrome, can lead to severe PH, highlighting the importance of prompt management in specialised care centres.

Ultrasound and computed tomography angiography diagnosis of fetal right atrial isomerism with cardiac total anomalous pulmonary venous connection and intestinal malrotation: a case report and literature review.

Right atrial isomerism is a rare and severe isomerism. It is frequently associated with complex congenital heart disease and various extracardiac anomalies. Imaging diagnosis of right atrial isomerism is a challenge. Multisystem and complex anomalies in a 24-week-old fetus were diagnosed with prenatal ultrasound, postnatal computed tomography angiography (CTA), and autopsy. The ultrasound detected most major cardiovascular anomalies including right atrial isomerism and total anomalous pulmonary venous connection. The CTA further detected thoracic and abdominal malformations such as bilateral morphologically right bronchus, diaphragmatic hernia, asplenia, midline liver, and intestinal malrotation. The autopsy confirmed both ultrasound and CTA findings with additional findings, namely, bilateral trilobed lungs and bilateral morphological right auricles. Prenatal ultrasound and postnatal CTA can be complementary to each other in detecting multi-system complex anomalies. Their combined use can be useful for prenatal counseling and postpartum management.

Factors associated with early postoperative mortality after total anomalous pulmonary venous connection repair: A retrospective cohort study.

Total anomalous pulmonary venous connection (TAPVC) is a rare congenital defect where pulmonary venous plexus fails to connect with the left atrium (LA). Surgical repair is the primary treatment for TAPVC, but factors influencing outcomes are not fully understood. This study investigates the early outcomes of surgical repair for TAPVC and associated factors. A retrospective cohort analysis was conducted on TAPVC patients who underwent surgical repair between 2012 and 2022. Data were collected from medical records and supplemented with phone call validation. Demographic characteristics, surgical data, diagnostic tests, and outcomes were analyzed. Statistical analysis included chi-square, t-tests, and multivariate logistic regression using SPSS. A total of 88 patients underwent surgical repair for TAPVC, resulting in a mortality rate of 21.6%. Weight and bypass time were significantly associated with patient survival. Female patients had a higher likelihood of death. The anatomic type did not significantly influence mortality. Patients with pulmonary venous obstruction (PVO) experienced a higher mortality rate. Notably, ligation of the vertical vein in supracardiac and infracardiac types was associated with lower mortality. In conclusion, our study identifies several key factors contributing to higher mortality rates following TAPVC surgery, including low weight, female gender, prolonged bypass time, and preoperative vein obstruction. Highlighting the significance of surgical technique, particularly the sutureless approach, we advocate for its meticulous consideration to achieve improved outcomes. Furthermore, our findings indicate a potential decrease in mortality associated with vertical vein ligation, which may mitigate the risk of post-repair heart failure. We suggest further rigorous studies to gain comprehensive insights into TAPVC surgical interventions.

Insight into the research history and trends of total anomalous pulmonary venous connection: a bibliometric analysis.

BACKGROUND: Total anomalous pulmonary venous connection (TAPVC) is a rare congenital heart disease characterized by the inability of all pulmonary veins to connect to the left atrium. Our previous bibliometric article summarized the characteristics of only the 100 most cited papers in TAPVC research. The purpose of this study was to use comprehensive bibliometric analysis to examine the development history, current status, and future trends in the field of TAPVC. METHODS: All publications on TAPVC published between 2000 and 2023 were collected from the Web of Science Core Collection. The publication and citation data were quantitatively analyzed by publication year, country, institution, author, and journal. Co-authorship and co-occurrence analyses were performed using VOSviewer, and keyword and reference bursts were identified using CiteSpace. Pearson's test was used to examine the correlations between two continuous variables. RESULTS: As of July 20, 2023, we identified 368 publications with 3320 citations. These publications were published in 132 journals and authored by 1835 researchers from 457 institutions in 47 countries. For the number of publications, the top country, top institution, top author, and top journals were the United States (n = 82), Shanghai Jiao Tong University (n = 13), Huiwen Chen (n = 9), and Annals of Thoracic Surgery and Pediatric Cardiology (n = 29 each), respectively. For the number of citations, the top country, top affiliation, top author, and top journal were the United States (n = 1348), University of Toronto (n = 250), Christopher A. Caldarone (n = 315), and Annals of Thoracic Surgery (n = 746), respectively. The number of national publications significantly correlated with GDP (R = 0.887, P < 0.001), research & development (R&D) expenditure (R = 0.375, P = 0.013), population (R = 0.694, P < 0.001), and journals (R = 0.751, P < 0.001). The number of national citations significantly correlated with GDP (R = 0.881, P < 0.001), R&D expenditure (R = 0.446, P = 0.003), population (R = 0.305, P = 0.037), and journals (R = 0.917, P < 0.001). International collaboration in the field of TAPVC was not well developed. The most commonly cited publication discussed era changes in mortality and reoperation rate in TAPVC patients. The most common keywords were "total anomalous pulmonary venous connection" and "congenital heart disease". The keyword "case report" appeared most recently, with an average occurrence year of 2021.8. The co-occurrence analysis grouped 26 keywords into six themes: surgical repair of TAPVC, postoperative pulmonary vein stenosis, surgical repair of TAPVC patients with heterotaxy, application of echocardiography in diagnosing TAPVC, application of echocardiography in the prenatal diagnosis of TAPVC, and application of the sutureless technique in the surgical repair of TAPVC patients with right atrial isomerism or a single ventricle. Citation burst detection identified 32 references with citation bursts, seven of which had ongoing citation bursts until 2023. CONCLUSIONS: This study conducted a bibliometric analysis to provide a comprehensive overview of TAPVC research. We hope to offer new ideas for promoting development in the field of TAPVC.

Total Anomalous Pulmonary Venous Connection in Adults: Should We Offer Surgery?

Background: We aim to determine the surgical outcomes of adult patients with total anomalous pulmonary venous connection (TAPVC) and examine the regression of pulmonary artery (PA) pressures after the procedure. Methods: We reviewed the hospital records from 2003 to 2022 and identified 49 adult patients with TAPVC. We assessed their surgical outcomes and the trend of PA pressures after the procedure. Continuous data are presented as mean ± SD or median (interquartile range) and categorical variables are presented as percentages. Results: The median age of the patients was 23 years (range 18-42) and 31 (63.3%) were male. Thirty-six patients (73.5%) had supracardiac TAPVC. The mean systolic PA pressure was 65.8 ± 16.4 mm Hg and it decreased by 47.9% (34%, 61.8%) after surgery. Moderate or more tricuspid regurgitation was seen in 27 (55.1%) patients before surgery; however, it was present in only 3 (6.1%) patients during early follow-up. There was no intraoperative or 30-day mortality, and the median hospital length of stay was six days. Long-term follow-up data were available for 29 patients with the average duration of follow-up being 5.6 years (range 6 months to 15 years) and the mean systolic PA pressures of this cohort was 29.8±7.9 mm Hg. Forty-six (93.1%) patients were asymptomatic; four women had uneventful pregnancies and delivered healthy children. Conclusion: Surgical repair of the naturally selected group of adult TAPVC patients can be performed safely with good results. Regression in flow-related pulmonary hypertension and an improvement in functional quality of life are seen in nearly all patients.

Clinical characteristics, imaging findings, management, and outcomes of patients with scimitar syndrome at a tertiary referral healthcare center in Colombia.

Scimitar Syndrome is part of a complex spectrum of congenital cardiovascular anomalies related to anomalous pulmonary venous return. Depending on the extent of involvement, treatment can be either expectant or surgical. Prognosis and survival have been controversial, with some results supporting early surgical management. This research aims to disclose the outcomes and describe the management, clinical and imaging characteristics of patients diagnosed with Scimitar Syndrome treated in a tertiary referral healthcare center. Longitudinal descriptive observational study. The study included all patients diagnosed with scimitar syndrome in our institution between January/2011 and December/2022. A description of the sociodemographic and clinical characteristics, diagnostic tools used, treatment features, and patient outcomes is provided. Eleven patients were included, with a mean age at diagnosis of five years (CI 0-17), six of which were female (54.55%). Nine (81.82%) patients had evidence of a scimitar vein on the chest radiograph, six (54.55%) cardiac dextroposition, six (54.55%) pulmonary hypoplasia, five (45.45%) right pulmonary artery hypoplasia, and three (27.27%) had aortopulmonary collaterals. Four (36.36%) patients had horseshoe lungs, and four (36.36%) had bronchopulmonary sequestration. In the associations, two (18.18%) patients were found to have an atrial septal defect, three (27.27%) ventricular septal defect, and one (9%) had Tetralogy of Fallot. Pulmonary hypertension was demonstrated in two (18.18%) patients. Seven (63.64%) required surgical management to correct the scimitar vein, and two patients died due to unrelated complications. Scimitar syndrome presents diagnostic and treatment challenges, necessitating a multidisciplinary approach for timely care. Chest radiography and CT scans are primary diagnostic tools, with surgical intervention often warranted alongside other heart defects or significant hemodynamic repercussions. Medical management is effective for mild to moderate cases. Long-term patient outcomes remain uncertain due to study limitations, but improved life expectancy is anticipated with ongoing care.

Isolated Partial Anomalous Pulmonary Veins: A 10-Year Experience at a Single Center.

INTRODUCTION: Isolated partial anomalous pulmonary venous connection (PAPVC) is difficult to diagnose, and surgical indications remain controversial. We reviewed 10 y of isolated PAPVC cases. METHODS: The data of patients with isolated PAPVC admitted to the Anzhen Congenital Heart Disease Department from 2010 to 2019 were reviewed retrospectively. RESULTS: Thirty patients, aged between 4 mo and 32 y, were included in this study. Significant correlations were found between the right ventricle (RV), end-diastolic dimension Z-score (RVED-z) and age (r = 0.398, P = 0.03), and between estimated pulmonary pressure and age (r = 0.423, P = 0.02). However, no significant correlations were found between the RVED-z and the number of anomalous pulmonary veins (r = 0.347, P = 0.061), between estimated pulmonary pressure and the RVED-z (r = 0.218, P = 0.248), and between estimated pulmonary pressure and the number of anomalous veins (r = 0.225, P = 0.232). Transthoracic echocardiography (TTE) confirmed 90% of isolated PAPVC cases. Surgical repair was performed in 29 patients with RV enlargement, persistent low weight, pulmonary hypertension, or respiratory symptoms. Among the surgical patients, nine had elevated pulmonary pressure before surgery, which decreased postoperatively; no mortality or reintervention was observed. The mean duration of echocardiographic follow-up was 1.9 y. CONCLUSIONS: TTE is recommended for routine assessments, and further clarification can be obtained with computed tomography when TTE proves inconclusive for diagnosis. Transesophageal echocardiography and computed tomography are further recommended for adult patients if TTE fails to provide clear results. PAPVC should be considered as an underlying cause when unexplained RV enlargement is observed. Surgery is recommended for patients with RV enlargement, pulmonary hypertension, or respiratory symptoms.

Congenital Pulmonary Lymphangiectasia Masked by Postoperative Pulmonary Venous Obstruction in an Infant with Total Anomalous Pulmonary Venous Connection.

Congenital pulmonary lymphangiectasia (CPL) is associated with fetal pulmonary venous obstructive physiology. The precise morbidity of CPL is unknown as CPL is generally fatal in neonates. Here, we report an infant with secondary CPL in total anomalous pulmonary venous connection (TAPVC). He developed severe pulmonary hypertension (PH) after corrective surgery for TAPVC. However, cardiac catheterization showed mild left pulmonary venous obstruction (PVO), which was deemed unnecessary for re-intervention. He died at 11 months-old due to an exacerbation of PH. Autopsy revealed medial hypertrophy of the pulmonary arteries, mild left PVO, and marked dilatation and proliferation of the pulmonary lymphatics which might have been involved in the PH, although CPL was not conclusively identified based on the previous biopsy findings. We should be aware of the possibility of CPL in addition to postoperative PVO when encountering patients with fetal pulmonary venous obstructive physiology. Furthermore, a cautious approach to the interpretation of lung biopsy results is warranted.

A rare variant of scimitar syndrome characterised by right pulmonary vein drainage to portal vein with eventeration of diaphragm.

While infradiaphragmatic total anomalous pulmonary venous drainage to portal vein is well described, hemianomalous drainage of right pulmonary veins to portal vein in Scimitar syndrome has not yet been reported.