Developmental abnormalities of the great vessels of the thorax and their embryological basis

Prenatal screening and diagnosis of pulmonary artery anomalies

Congenital pulmonary artery anomalies are rare. Their antenatal diagnosis requires good knowledge of fetal cardiac anatomy because their clinical presentation varies depending on the type and severity of the underlying lesion. Screening of these vascular anomalies can be straightforward in some cases because of significant associated consequences that are detected easily on ultrasound, while other anomalies have considerably less obvious features. There may be an associated genetic syndrome. The aim of this review was to define anomalies of the main pulmonary artery and its branches and to propose, through the identification of suspicious findings during routine antenatal heart examination, an optimal screening method for the pulmonary artery pathway. We propose that pulmonary artery anomalies can be classified antenatally into four types of disorder. Herein we describe 14 cases subgrouped accordingly as: anomalies of the pulmonary valvular region, with stenosis or atresia of the valve (n = 4); conotruncal abnormalities (n = 4); anomalies associated with abnormal origin or course of the pulmonary artery (n = 4); and anomalies associated with abnormal growth of the pulmonary artery and its branches (n = 2). We highlight the need to differentiate the three-vessel view from the three-vessel-and-trachea view when assessing a fetus with a congenital pulmonary artery anomaly. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Proximal Interruption of Pulmonary Artery: Spectrum of Radiological Findings With Emphasis on Chest Radiograph and Contrast-Enhanced Computed Tomography (CECT)

Introduction Proximal interruption of pulmonary artery (PIPA) is a congenital anomaly presenting with aberrant termination of the pulmonary artery at the hilum. It results in a variety of radiological and clinical manifestations. Clinically, isolated PIPA can be asymptomatic till late adulthood or can present with dyspnoea, chest discomfort, hemoptysis and recurrent infections. PIPA can be associated with multiple cardiovascular anomalies such as tetralogy of Fallot (TOF), ventricular septal defects (VSD), and scimitar syndrome. We present a spectrum of cases with both isolated proximal interruption of the pulmonary artery and cases associated with other cardiovascular abnormalities. Typical chest radiographs and chest contrast-enhanced computed tomography (CECT) findings are discussed and demonstrated in detail. Proper and early diagnosis is a crucial step as it can significantly modify the treatment choice, thereby reducing morbidity. Objective To document the different presentations of the proximal arrest of pulmonary arteries, to document associations with cardiovascular and pulmonary manifestations, and to elaborate on and demonstrate the various radiological imaging findings. Material and methods All the cases that were reported with proximal interruption of pulmonary artery on the CECT studies conducted between 2019 and 2022 at a tertiary care hospital in Telangana, India. The demographic data, clinical presentation, chest radiographs, and chest CECT were collected retrospectively. Data analysis was done using Microsoft Excel 2019 to calculate descriptive statistics. A total of 22 cases were identified of which three cases were excluded of as they were previously operated and 19 cases were taken as the study population. Results Nineteen patients were included in the study. Demographic details, clinical history, CECT, and chest radiographs were collected wherever available. The majority of the cases belonged to the ≤ 10 yrs age group with the most common clinical presentation being a previous diagnosis of tuberculosis or recurrent upper respiratory tract infections. The predominant findings on chest radiographs were deviation of the trachea to the affected side, volume loss in the ipsilateral lung field, and compensatory hyperinflation of the contralateral lung field. On the CECT chest, the main findings were interrupted pulmonary artery, hypoplastic lung fields with bronchiectasis, or ground glassing. Associated cardiovascular and pulmonary malformations were identified with notable cases: TOF, right-sided aortic arch and scimitar syndrome. Their typical imaging findings have been elucidated and discussed in detail. Conclusions Patients with recurrent respiratory infections or hemoptysis having hypoplastic lung field with hyperinflation of the contralateral lung on chest radiographs should be evaluated for pulmonary artery interruptions. Chest CECT allows evaluation of the bronchial tree and lung parenchyma at the same time which helps distinguish pulmonary interruption from conditions such as Swyer-James-Macleod syndrome, pulmonary hypoplasia, thromboembolism and arteritis. Cases with PIPA can also be associated with cardiovascular and pulmonary anomalies such as TOF, partial anomalous pulmonary venous connection (PAPVC), and VSD. The knowledge of these associations is essential as they can influence the mode of treatment and can help reduce the long-term morbidity and mortality associated with the condition.

CT evaluation of aberrant right subclavian artery: anatomy and clinical implications

PurposeThe aim of the study was to perform CT angiography-based evaluation of aberrant right subclavian artery prevalence, anatomy, and its influence on clinical symptoms.

METHODS

A total of 6833 patients who underwent 64-slice or dual-source CT angiography and those who revealed aberrant right subclavian artery underwent evaluation of its anatomy and were interviewed for the presence of clinical symptoms.

RESULTS

Aberrant right subclavian artery was found in 32 (0.47%) patients consisting of 13 males and 19 females, with mean age of 60.8±13.4 years. Among the interviewed 30 (94%) patients, oesophageal compression was observed in 14 cases (47%) and tracheal compression in three cases (10%). None of the patients underwent surgery related to aberrant right subclavian artery. Dysphagia was the most common clinical symptom in nine cases (30%), and in those patients the median distance between aberrant right subclavian artery and trachea was lower (4 mm) than in individuals without dysphagia (7.5 mm) (p = 0.009). The median lumen area of the aberrant right subclavian artery at the level of oesophagus was higher in patients with dysphagia (208 mm2) compared with individuals without dysphagia (108 mm2) (p = 0.01).

CONCLUSIONS

Aberrant right subclavian artery is a rare occurring abnormality in CT angiography. In the evaluated adult population, the most common symptom was dysphagia, which occurred in patients with decreased distance between aberrant right subclavian artery and trachea and increased lumen area of the aberrant artery at the level of compressed oesophagus.

Persistent Left Superior Vena Cava in Pediatric Patients

A persistent left superior vena cava (PLSVC) is a congenital anomaly of the systemic venous system. This anomaly is often discovered as an incidental result during central venous catheterization passing through the left subclavian or the left internal jugular vein. We report two cases of PLSVC in pediatric patients.

An incomplete vascular ring causing respiratory distress

Kommerell’s diverticulum is a rare saccular aneurysmal dilation of the descending aorta. We report a case of a 3.5-year-old boy with the extremely rare combination of Kommerell’s diverticulum with a right descending aorta and proximal patent ductus arteriosus aneurysm forming an incomplete vascular ring. To our knowledge, this rare case has not been reported to date.

Aberrant right subclavian artery syndrome manifesting as focal tracheomalacia

Tracheomalacia is one of the rarest etiologies of chronic cough. Herein, we present the case of an elderly woman with chronic cough who on detailed evaluation was found to have focal (localized) tracheomalacia due to compression by an aberrant right subclavian artery (arteria lusoria). The absence of dysphagia in this patient also deserves particular mention.

Congenital anomalies of the pulmonary arteries: spectrum of findings on computed tomography

OBJECTIVE

Congenital anomalies of the pulmonary arteries are uncommon. They can occur in isolation or in association with congenital heart defects. Isolated congenital anomalies remain undiscovered until they are reported as incidental findings on imaging tests, usually not until adolescence. We review the embryological development and normal anatomy of the pulmonary arteries as well as the spectrum of computed tomography findings for various congenital anomalies: unilateral interruption of the pulmonary artery, anomalous origin of the left pulmonary artery (pulmonary artery sling), idiopathic aneurysm of the pulmonary artery, and other anomalies associated with congenital heart defects.

CONCLUSION

Congenital anomalies of the pulmonary arteries represent a diagnostic challenge for clinicians and radiologists. Computed tomography is useful for their diagnosis, and general radiologists need to be familiar with their imaging appearance because they are often discovered incidentally.

Congenital arch vessel anomalies in CHARGE syndrome: A frequent feature with risk for co-morbidity

Background

CHARGE syndrome is a complex multiple congenital malformation disorder with variable expression that is caused by mutations in the CHD7 gene. Variable heart defects occur in 74% of patients with a CHD7 mutation, with an overrepresentation of atrioventricular septal defects and conotruncal defects — including arch vessel anomalies.

Methods and results

We report an index patient with an arch vessel anomaly underlying serious feeding problems that resolved after arch vessel surgery. This led us to examine the incidence of arch vessel anomalies in our previously studied cohort of 299 patients with a CHD7 mutation. Forty-two patients (14%) had an aortic arch anomaly, mostly aberrant subclavian artery or right aortic arch, which usually occurred in combination with other congenital heart defects (81%). The majority of these patients also had feeding problems that may be linked to their arch anomaly, but insufficient information was available to exclude other causes.

Conclusions

Arch vessel anomalies occur in a significant proportion of patients with a CHD7 mutation, and these anomalies may cause morbidity due to compression of the esophagus or trachea. Since symptoms of vascular compression can mimic those caused by other abnormalities in CHARGE syndrome, it is important to be aware of arch vessel anomalies in this complex patient category. Whether a solitary arch vessel anomaly is an indicator for CHARGE syndrome still needs to be studied, but doctors should look out for other CHARGE syndrome features in patients with arch vessel anomalies.

Proximal Interruption of the Pulmonary Artery: A Case Series

We present a few cases of Proximal Interruption of the Pulmonary Artery, an uncommon developmental anomaly associated with congenital heart disease. The cases had varied clinical presentations. Chest radiograph showed a hypoplastic lung with an ipsilateral small hilum on the side of the interruption and hyperinflation of the contralateral lung. Contrast CT confirmed the diagnosis, demonstrating non-visualization of the left or right pulmonary artery, and other related findings.

Central Venous Catheter Intravascular Malpositioning: Causes, Prevention, Diagnosis, and Correction

Despite the level of skill of the operator and the use of ultrasound guidance, central venous catheter (CVC) placement can result in CVC malpositioning, an unintended placement of the catheter tip in an inadequate vessel. CVC malpositioning is not a complication of central line insertion; however, undiagnosed CVC malpositioning can be associated with significant morbidity and mortality. The objectives of this review were to describe factors associated with intravascular malpositioning of CVCs inserted via the neck and chest and to offer ways of preventing, identifying, and correcting such malpositioning. A literature search of PubMed, Cochrane Library, and MD Consult was performed in June 2014. By searching for “Central line malposition” and then for “Central venous catheters intravascular malposition,” we found 178 articles written in English. Of those, we found that 39 were relevant to our objectives and included them in our review. According to those articles, intravascular CVC malpositioning is associated with the presence of congenital and acquired anatomical variants, catheter insertion in left thoracic venous system, inappropriate bevel orientation upon needle insertion, and patient’s body habitus variants. Although plain chest radiography is the standard imaging modality for confirming catheter tip location, signs and symptoms of CVC malpositioning even in presence of normal or inconclusive conventional radiography findings should prompt the use of additional diagnostic methods to confirm or rule out CVC malpositioning. With very few exceptions, the recommendation in cases of intravascular CVC malpositioning is to remove and relocate the catheter. Knowing the mechanisms of CVC malpositioning and how to prevent, identify, and correct CVC malpositioning could decrease harm to patients with this condition.

Some mice feature 5th pharyngeal arch arteries and double-lumen aortic arch malformations

A 5th pair of pharyngeal arch arteries (PAAs) has never been identified with certainty in mice. Murines in general are considered to not develop a 5th pair. If true, the significance of the mouse as a model for researching the genesis of malformations of the great intrathoracic arteries is limited. We aimed to investigate whether mouse embryos develop a 5th pair of PAAs and to identify malformations known to be caused by defective remodelling of the 5th PAAs. We employed the high-resolution episcopic microscopy method for creating digital volume data and three-dimensional (3D) computer models of the great intrathoracic arteries of 30 mouse embryos from days 12-12.5 post conception and 180 mouse fetuses from days 14.5 and 15.5 post conception. The 3D models of the fetuses were screened for the presence of a double-lumen aortic arch malformation. We identified such a malformation in 1 fetus. The 3D models of the embryos were analysed for the presence of 5th PAAs. Six of the 30 embryos (20%) showed a 5th PAA bilaterally, and an additional 9 (30%) showed a 5th PAA unilaterally. Our results prove that some mice do develop a 5th pair of PAAs. They also show that malformations which occur rarely in humans and result from defective remodelling of the left 5th PAA can be identified in mice as well. Thus, the mouse does represent an excellent model for researching the mechanisms driving PAA remodelling and the genesis of malformations of the great intrathoracic arteries.

Congenital systemic-pulmonary collateral vein unexpectedly noticed after central venous catheter insertion

Congenital systemic-pulmonary collateral vein (i.e. levoatriocardinal vein) is an uncommon cardiac anomaly. We report a rare case of congenital systemic-pulmonary collateral vein incidentally noticed after accidental migration of a central venous catheter. Cardiac CT showed the vertical vein connected to the left upper pulmonary vein (LUPV) and another thin abnormal vessel was shown running caudally from the LUPV, connecting to the coronary sinus. Furthermore, the normal connection between the LUPV and the left atrium remained. There were two levoatriocardinal veins from the LUPV without atrial egress failure. To our knowledge, this might be the first report of such a case.

A right-left aortic arch pattern made up by a bicarotid trunk, a left subclavian, a left vertebral and a right retroesophageal subclavian artery

We present several vascular variations of the aortic arch vessels observed in a 35-year-old man during magnetic resonance angiography (MRA). The arterial branches of the aortic arch are from right to left: a bicarotid trunk, a left vertebral artery, a left subclavian artery, and a right retroesophageal subclavian artery. The right vertebral artery arises from the right carotid artery. Although a right retroesophageal subclavian artery has been reported in association with different anatomic variations of the aortic arch, to our knowledge this is the first MRA description of this particular combination of variations.

Common aortic arch anomalies: diagnosis and management

Vascular rings are a rare form of congenital malformation that completely encircle the trachea and esophagus with vascular structures. The two most common forms are double aortic arch and right aortic arch with an aberrant left subclavian artery and a left-sided ligamentum arteriosum. Patients may present with symptoms of airway or esophageal impingement, including "noisy breathing," stridor, respiratory distress, difficulty feeding, or dysphagia. Typically, the more severe the airway or esophageal compression, the earlier the age at presentation. Diagnosis was traditionally made by posterior compression of the esophagus demonstrated by barium swallow; in the current era, CT angiography or magnetic resonance angiography is used. Although helpful to delineate intracardiac anatomy and associated structural heart defects, echocardiography is less useful for imaging vascular structures when atretic segments comprise part of the vascular ring. Management includes surgical division of the structures contributing to the vascular ring. Some centers also perform surgical remodeling of Kommerell's diverticulum because this structure may contribute to continuing tracheal or esophageal compression even after the ring has been released. Patients with associated tracheomalacia may continue to have symptoms that can last for months, but ultimately resolve with time. Long-term results are generally excellent with minimal morbidity and mortality.

A case of persistent left and absent right superior caval vein: An anatomical and embryological perspective

The relatively common persistent left superior caval vein (LSCV) is in most cases associated with doubling of the superior caval vein. A persistent LSCV with absent right superior caval vein (RSCV)-a rather rare event-was found during our course of gross anatomy. The LSCV drained into an enlarged coronary sinus, which was partly accompanied by an apparent "double" sinus of normal size draining into this enlarged coronary sinus. Histological and immunofluorescence studies using antibodies against smooth and cardiac muscle actins were performed. The terminal part of the LSCV near the opening into the right atrium contained cardiac actin as expected for a normal derivative of the left sinus horn. Previously only one case of doubled coronary sinus with LSCV has been reported and this abnormality was explained by splitting of the sinus. In our case, the partly doubled coronary sinus had the structure of coronary veins. Mechanical forces have been invoked for the obliteration of the LSCV. Therefore, we examined thirteen human embryos from 15 mm to 32 mm crown-rump length. In one embryo, we found a persistent LSCV together with an enormously enlarged left atrium. Contrary to previous suggestions our data indicate that during normal development a compression of the left anterior cardinal vein does not sufficiently explain the obliteration of the left and the persistence of the right vein. We therefore believe that beside a left dominated blood flow of head and arm, genes for left-right signaling may have to be taken into consideration.

Atrioventricular Canal Defect, Pulmonary Artery Sling, and Aortic Arch Anomaly in a Patient With Down Syndrome

There is a high prevalence of congenital heart disease in patients with Down syndrome. Atrioventricular (AV) canal defects, ventricular septal defects, and a patent ductus arteriosus are most commonly seen. The authors present a patient with a unique constellation of findings, including an AV canal defect, pulmonary artery sling, and an aberrant right subclavian artery diagnosed on a screening echocardiogram. Additional imaging modalities confirmed this atypical concurrence of congenital heart defects and also proved the accuracy of echocardiography in diagnosing rare combinations of congenital heart disease.

Paediatric multidetector CT angiography: spectrum of congenital thoracic vascular anomalies

Multidetector row CT (MDCT) is a non-invasive and rapid technique used for the evaluation of paediatric vascular diseases as an alternative to conventional angiography. Three-dimensional (3D) images allow excellent display of vascular anomalies that can be used as a vascular road map by surgeons. The aim of this pictorial review is to demonstrate diagnostic MDCT angiographic findings of various congenital thoracic vascular anomalies in paediatric patients. It is important to recognize these anomalies early for proper treatment and follow-up, and also to prevent morbidities and mortalities.

Prenatal diagnosis of absent right and persistent left superior vena cava

OBJECTIVE

Persistence of left superior vena cava (LSVC) is a known variant of the systemic venous return. In the setting of an otherwise structurally normal heart, absence of the right superior vena cava (RSVC) but persistence of the LSVC is rare.

METHODS

We describe the prenatal findings of a fetus with absent right and persistent LSVC.

RESULTS

A dichorionic diamniotic twin pregnancy was referred to our centre with cardiac disproportion. Twin A had disproportion at four-chamber level, an absent right but persistent LSVC draining to an enlarged coronary sinus and a hypoplastic transverse aortic arch (<2 mm). Postnatal echocardiography of the asymptomatic baby confirmed the prenatal diagnosis, and serial echocardiograms demonstrated general hypoplasia of the aortic arch but no discrete coarctation (CoA). No intervention was required and the baby is thriving aged 10 months.

CONCLUSION

Persistence of LSVC is a known variant of the systemic venous return. In the setting of an otherwise structurally normal heart, absence of the right but persistence of LSVC is rare.

Left–right asymmetry and congenital cardiac defects: Getting to the heart of the matter in vertebrate left–right axis determination

Cellular and molecular left-right differences that are present in the mesodermal heart fields suggest that the heart is lateralized from its inception. Left-right asymmetry persists as the heart fields coalesce to form the primary heart tube, and overt, morphological asymmetry first becomes evident when the heart tube undergoes looping morphogenesis. Thereafter, chamber formation, differentiation of the inflow and outflow tracts, and position of the heart relative to the midline are additional features of heart development that exhibit left-right differences. Observations made in human clinical studies and in animal models of laterality disease suggest that all of these features of cardiac development are influenced by the embryonic left-right body axis. When errors in left-right axis determination happen, they almost always are associated with complex congenital heart malformations. The purpose of this review is to highlight what is presently known about cardiac development and upstream processes of left-right axis determination, and to consider how perturbation of the left-right body plan might ultimately result in particular types of congenital heart defects.