Morphological features of the levoatriocardinal (or pulmonary-to-systemic collateral) vein

Is it really a levoatrial cardinal vein?

With the advent of computed tomographic interrogation, it is increasingly frequent to find venous channels that provide direct connections between the pulmonary and systemic veins. These channels, before the introduction of three-dimensional techniques for clinical imaging, were usually found providing an "overflow" for the obstructed left atrium in settings such as hypoplastic left heart syndrome, or divided left atrium. Similar channels, however, had been described almost 100 years ago, with one accurately described as a jugulo-pulmonary vein. Nowadays, however, it is much more usual to find the channels described as levoatrial cardinal veins, even though it is recognized that they are not "levo," often not "atrial," and for sure not "cardinal." In this review, we assemble the evidence supporting the notion that they are better considered as pulmonary-to-systemic collateral channels. We emphasize their similarity, in terms of development, to the sinus venosus and coronary sinus defects.

A rare pulmonary-to-systemic venous connection associated with the partially anomalous pulmonary venous connection

BACKGROUND

We report an extremely rare case of pulmonary-to-systemic venous connection associated with the partially anomalous pulmonary venous connection. Our case highlights that computed tomography angiography has a significant diagnostic and differential value for this rare anomaly.

METHODS AND RESULTS

A 32-year-old male presented with chest discomfort for 2 weeks. The electrocardiogram and laboratory were unremarkable abnormalities. Transthoracic echocardiography suggested an enlargement of the right atrium and right ventricle. Cardiac computed tomography angiography images showed partial anomalous drainage of the right superior pulmonary vein into the superior caval vein, and a large pulmonary-to-systemic venous connection from the right middle pulmonary vein into the superior vena cava resulting in left atrial to systemic venous shunt. The patient underwent a successful thoracoscopic correction of partially anomalous pulmonary venous connection. Post-procedural course was uneventful, and he was discharged after 7 days.

DISCUSSION

Pulmonary-to-systemic venous connection may also be called a levoatriocardinal vein. The embryological origin of this venous connection is an abnormal persistency of the splanchnic plexus connecting the pulmonary venous plexus and the cardinal system. The diagnosis of these rare types of the pulmonary to systemic communications has important clinical implications. We report an extremely rare case with pulmonary-to-systemic venous connection from the right middle pulmonary vein into the superior caval vein, although the connection might have been considered a levoatriocardinal vein, there is no separate formation of the right middle pulmonary vein at the time of existence of the splanchnic plexus, so it is inappropriate to explain the collateral channel encountered in our patient on the basis of an embryological remnant, a more appropriate term for these anomalies would be a "pulmonary-to-systemic collateral vein". Because the venous collateral pathway may be a source of the persistent left-to-right shunt and cause clinical manifestations of chronic right heart volume overload later in life. Therefore, we have performed successful thoracoscopic correction of partial anomalous pulmonary venous drainage. The Post-procedural course was uneventful.

CONCLUSION

The pulmonary-to-systemic venous connection associated with the partially anomalous pulmonary venous connection is a rare congenital malformation. Computed tomography angiography as a noninvasive imaging method plays an important diagnostic and differential value for this entity.

Levoatrial Cardinal Vein: Occluder Embolization and Complication Management

In rare cases, levoatrial cardinal vein may occur as an isolated condition without additional congenital anomalies. Depending on the direction and flow of the shunt, this pathology may produce symptoms; alternatively, it may be asymptomatic, as in the case presented in this study. In asymptomatic cases, complications, such as paradoxical embolism and brain abscess, can arise later. In the 11-year-old patient whose case is presented here, the levoatrial cardinal vein was asymptomatic and incidentally detected. The percutaneous closure method was applied first. However, by 16 hours after the procedure, the occluder device had embolized to the iliac artery. Emergency surgery was performed; first, the occluder device was removed, and levoatrial cardinal vein ligation was then performed via a mini-thoracotomy. The symptoms, diagnosis, and treatment modalities of isolated levoatrial cardinal vein are discussed in the context of this case described herein.

Levoatrial cardinal vein with left-to-right shunt in a neonate: Multi-imaging diagnosis

We present a rare case of a levoatrial cardinal vein identified during the work-up of a patient with coarctation of the aorta. Early diagnosis and repair in the neonatal period prevented future manifestations of left-to-right shunt and the need for reoperations, in contrast with the later-age presentation of this congenital anomaly. An integrative approach was crucial for prompt detection, intraoperative confirmation and complete one-stage repair.

Extracardiac Pulmonary-Systemic Connection via Persistent Levoatriocardinal Vein in Adults

The levoatriocardinal vein is a very rare but clinically important intrathoracic venous anomaly that connects the systemic (cardinal) and pulmonary venous channels. We report 4 adults with pulmonary-systemic venous communications that can explain the morphology of the extracardiac interatrial shunting through the persistent levoatriocardinal vein. We discuss the imaging features of the 2 types of such communications: direct connection of the levoatriocardinal vein (1) with the left atrium and (2) with the left superior pulmonary vein in the absence of obstructive left heart disease. Accurate characterization of these diagnostically challenging cases is important because in addition to hemodynamic imbalance they are at risk of paradoxical embolism. Computed tomography and magnetic resonance imaging are noninvasive imaging techniques that should play increasingly important roles in the evaluation of these anomalies.

Functional total anomalous pulmonary venous connection via levoatriocardinal vein

We report a fetal case of double outlet right ventricle, mitral atresia, and intact atrial septum. Although the pulmonary veins were connected to the left atrium, pulmonary venous blood drained into the right superior vena cava via the stenotic levoatriocardinal vein (LACV), which resulted in a circulation resembling total anomalous pulmonary venous connection (TAPVC) with pulmonary venous obstruction. Since the pulmonary veins were connected to both the stenotic LACV and the "dead-end" left atrium, the pulmonary venous flow had a to-and-fro pattern along with atrial relaxation and contraction. Postnatal echocardiography and computed tomography confirmed the diagnosis of normally connected but anomalously draining pulmonary veins via the LACV. Surgical creation of an atrial septal defect on the day of birth successfully relieved pulmonary venous obstruction. Normally connected but anomalously draining pulmonary veins via the LACV should be considered for TAPVC differential diagnosis in fetuses with a left-side heart obstruction.

Patent Levoatrial Cardinal Vein Without Left Heart Hypoplasia

We report a very rare case of a 38-year-old woman with an anomalous vein connecting the left atrium and superior vena cava. This vein originated from the roof of the left atrium and crossed the midline to join the normal right superior vena cava. Furthermore, there was no hypoplasia of the left heart, the atrial septum was intact, and all four pulmonary veins drained normally into the left atrium. Three-dimensional reconstructions and sagittal views on preoperative computed tomography clearly demonstrated a communication between the superior vena cava and the left atrium. The patient experienced increasing left-to-right shunt ratio and underwent successful surgical correction 3 years after the original diagnosis via ligation of the anomalous vein. This abnormal vein was considered to be a levoatrial cardinal vein. The embryology, physiology, diagnosis, and surgical repair of this rare lesion are discussed.

Hypoplasia of the left heart

The lesion that, nowadays, is most usually described as “hypoplastic left heart syndrome”, was initially described in terms of “hypoplasia of the aortic outflow tract complex”.1 Sporadic cases with aortic atresia, an intact ventricular septum, and gross hypoplasia of the left ventricle, had been described long before, but it was Noonan and Nadas, in a landmark study, who coined the term “hypoplastic left heart syndrome”.2 The paediatric cardiac community has now accepted this term uniformly, although as we will see, problems remain with regard to precisely which malformations should be included within the “syndrome”. The term itself, nonetheless, is not beyond criticism. This is because, for those working in the genetic community, a “syndrome”, by definition, is a constellation of anomalies afflicting multiple systems of organs. The so-called “hypoplastic left heart syndrome”, however, almost always involves only the heart and the great arteries. Thus, according to the geneticists, it should not strictly be described as a “syndrome”, although the Nomenclature committee of the International Coding Project have marshalled arguments in favour of the term. In this review, nonetheless, we will skirt these problems with the use of “syndrome”, and simply describe the morphology as seen in patients unified because they have hypoplasia of the left heart.

Bilateral pulmonary artery banding for resuscitation in hypoplastic left heart syndrome

We report a case of a hypoplastic left heart syndrome with a nearly intact atrial septum and an obstructed anomalous pulmonary to systemic venous connection. Surgical atrial septectomy followed by bilateral pulmonary artery banding provided an optimal condition for the Norwood operation.

Mitral and aortic atresia associated with hypoplastic right lung, crossover segment of right lower lobe, and anomalous scimitar-like right pulmonary venous connection with inferior vena cava: clinical, angiocardiographic, and autopsy findings in a rare case

A newborn female infant was found to have a unique and previously unreported group of anomalies: (1) mitral and aortic atresia with a highly obstructive atrial septum; (2) hypoplasia of the right lung with a crossover segment involving the right lower lobe; (3) normally connected pulmonary veins, two from the left lung and one from the right; and (4) a large anomalous branch of the right pulmonary vein of scimitar configuration that anastomosed with the normally connected right pulmonary vein and with the inferior vena cava (IVC). The scimitar vein appeared obstructed at its junction with the right pulmonary vein and at its junction with the inferior vena cava within the hepatic parenchyma. To our knowledge, this is the first report of a scimitar-like vein coexisting with mitral and aortic atresia and connecting both with the right pulmonary vein and with the inferior vena cava. The highly obstructed left atrium was partially decompressed by retrograde blood flow via the normally connected right pulmonary vein to the anomalous scimitar venous pathway and thence to the inferior vena cava via a pulmonary-to-IVC collateral vein.

The levoatriocardinal vein: morphology and echocardiographic identification of the pulmonary-systemic connection

OBJECTIVES

This study considers the array of pulmonary-systemic connections made by the levoatriocardinal vein. The primary and associated lesions that play a role in forming this vein are examined, and echocardiography is discussed as a method for its rapid identification.

BACKGROUND

The levoatriocardinal vein is a pulmonary-systemic connection that provides an alternative egress for pulmonary venous blood in left-sided obstructive lesions. It is thought to result from the persistence of anastomotic channels that connect the capillary plexus of the embryonic foregut to the cardinal veins. Only 12 cases of levoatriocardinal vein have been reported since its first description in 1926. A comprehensive description of the morphology and echocardiographic identification of this lesion has been unavailable because of its rarity.

METHODS

A retrospective study was performed in 13 patients with a levoatriocardinal vein from the University of California, San Francisco. Echocardiographic findings were compared with those obtained by angiography or at necropsy. In addition, the details of 12 previously published case reports were reviewed. Age at presentation, primary obstruction to pulmonary venous return, integrity of the atrial septum and origin and drainage of the levoatriocardinal vein were compared.

RESULTS

Patient age at presentation was < 2 years, with most patients presenting before age 6 months. Variations of the hypoplastic left heart syndrome accounted for the majority of primary defects encountered, although multiple but less severe left-sided lesions were seen. The atrial septum was functionally intact in most patients. The levoatriocardinal vein, defined echocardiographically, originated predominantly from the smooth-walled left atrium and drained to the superior vena cava or innominate vein; however, variations of this pattern existed.

CONCLUSIONS

As a physiologic entity, the levoatriocardinal vein provides a mechanism for decompression of pulmonary venous return primarily in patients with left ventricular inflow obstruction. A levoatriocardinal vein is thought to form when the atrial septum fails to provide an alternate egress for left atrial blood. However, when a septal defect or alternative shunt occurs in conjunction with a levoatriocardinal vein, the clinical presentation may be postponed. Echocardiography provides a rapid, noninvasive modality for identifying the pulmonary-systemic connection, which may masquerade as the vertical vein in anomalous pulmonary venous connection or act as an occult source of left to right shunting in patients undergoing surgery for hypoplastic left heart syndrome.