Total Anomalous Pulmonary Venous Return with No Connection

Graphical abstract

Highlights

• •Total anomalous pulmonary venous return with no connection has a poor prognosis.
• •Echocardiography aids in diagnosing unique features associated with this disease.
• •Additional diagnostic imaging modalities may be needed to confirm diagnosis.

Introduction

Total anomalous pulmonary venous return with no connection, also known as common pulmonary vein atresia, presents immediately after birth in the neonate with severe, life-threatening cyanosis. Echocardiography is helpful in diagnosing specific characteristics of this disease after birth. Patients with this disease are often in respiratory failure and are frequently placed on high-frequency oscillator ventilation. Moreover, this diagnosis can mimic pulmonary hypertension of the newborn and lead to a management strategy that would be ineffective. Because of limited acoustic windows, other imaging modalities may be required to confirm the diagnosis. Management options for total anomalous pulmonary venous return with no connection are quite limited because there is significant damage to the pulmonary vascular bed, and the cyanosis is often irreversible despite ventilation strategies. Extracorporeal membrane oxygenation can support the circulation for a limited period of time, but often surgery to connect the pulmonary venous confluence to the left atrium is unsuccessful and does not reverse the lung disease. For these reasons, the majority of patients with this rare disorder succumb to this disease. This case report highlights the features of this congenital heart defect seen on echocardiography and also describes the limitations and potential need for other imaging modalities in the diagnosis and management of these patients.

Case Presentation

The patient was a preterm infant born at 32 weeks’ gestation who was transferred from an outside hospital for respiratory failure. His prenatal history was limited as the mother had limited prenatal care with no reported fetal ultrasound examinations. His perinatal history was remarkable for persistent late decelerations necessitating early cesarean section. On delivery, the neonate was apneic despite stimulation and positive pressure ventilation. He was intubated and given surfactant. His oxygen saturation remained in the 50% to 65% range on 100% fraction of inspired oxygen. His chest x-ray showed diffuse whiteout of both lungs. His blood gases showed mixed severe respiratory and metabolic acidosis. Prostaglandin infusion at a rate of 0.01 μg/kg/min was initiated because of the concern for cyanosis. Blood cultures were drawn, and antibiotics were started. Inhaled nitric oxide was also started, and the patient was subsequently transferred to our institution. On arrival, dopamine was initiated for hypotension, and his ventilation strategy was changed to high-frequency oscillation.

Echocardiography was performed shortly upon presentation to the cardiac intensive care unit. The pulmonary veins were not well visualized, though there was a suggestion of a small pulmonary venous confluence behind the left atrium (Figure 1, Video 1). A blind-ended vertical vein was suspected, but its connection back to the heart could not be identified. Thus, no flow was seen from the pulmonary venous confluence to either the left atrium or to the systemic venous system by two-dimensional or color Doppler. The echocardiogram showed exclusive right-to-left shunting across the atrial septum with a very small left atrium, as is typical of patients with totally anomalous pulmonary venous connection (Figure 2, Video 2). The right ventricle was markedly dilated, with marked septal bowing into the left ventricle and moderate systolic dysfunction, suggesting that there was severe pulmonary hypertension. A large patent ductus arteriosus was seen with almost exclusive right-to-left shunting also suggesting pulmonary hypertension with high pulmonary vascular resistance (Figure 3, Video 3). The transverse arch demonstrated retrograde diastolic flow (Figure 4, Video 4). There was no aortic insufficiency or evidence of coarctation of the aorta as the cause of the abnormal aortic flow pattern. With retrograde diastolic flow in the aorta seen on echocardiography, head ultrasound was performed to rule out a vein of Galen defect. (A vein of Galen is a cerebrovascular malformation of the arteries, which sometimes appears on echocardiography as retrograde diastolic flow in the descending aorta.) With all the right-to-left atrial shunting and the diminutive left atrium visualized on echocardiography, there was a high level of suspicion for severe pulmonary venous obstruction (Table 1). All these findings also provided evidence of severe pulmonary hypertension, which would be seen in severely obstructed total anomalous pulmonary venous return. The clinical management of the child was then adjusted to discontinue prostaglandins because of the concern for potential pulmonary venous obstruction. Head ultrasound showed no findings to suggest a vein of Galen defect. With the echocardiographic findings and the inability to accurately document the pulmonary veins returning to the heart, computed tomographic angiography was performed. At the same time, the cardiac catheterization laboratory was activated in case angiography was required. During computed tomographic angiography, there were difficulties timing the contrast injection appropriately because of the neonate's tachycardia and clinical instability. Thus, findings were nondiagnostic. Urgent cardiac catheterization was then performed. Limited angiography demonstrated that the pulmonary veins from each lung segment drained into a short common vein, which was atretic with no obvious egress. Instead, contrast was seen decompressing into a dense, fine network of bronchial veins to the innominate vein and below the diaphragm to other systemic veins (Figure 5, Video 5). These findings were consistent with a diagnosis of total anomalous pulmonary venous return with no connection or common pulmonary vein atresia. After a discussion with all treating physicians, it was felt that there was no viable intervention to repair this defect. Surgery was not an option for the patient because of the hypoplastic common pulmonary vein that was blind ended and did not drain back into the heart. The patient was brought back to the cardiac intensive care unit, where he expired shortly thereafter at around 12 hours of life.

Figure 1.

Subxiphoid left anterior oblique view demonstrating a small pulmonary venous confluence behind the heart. A blind-ended vertical vein is seen connected to the confluence. LA, Left atrium; RA, right atrium.

Figure 2.

Subxiphoid left anterior oblique view demonstrating right-to-left flow across the atrial septum. LA, Left atrium; PFO, patent foramen ovale; RA, right atrium.

Figure 3.

High parasternal view (ductal view) using color Doppler demonstrating all right-to-left flow across the patent ductus arteriosus (PDA). LPA, Left pulmonary artery; RPA, right pulmonary artery.

Figure 4.

Suprasternal sagittal view of aortic arch in color-compare mode demonstrating reversal of flow in the transverse arch during diastole. Asc Ao, Ascending aorta; Desc Ao, descending aorta; TA, transverse arch.

Table 1.

Unique echocardiographic findings in total anomalous pulmonary venous return with no connection

•Exclusive right-to-left shunting across atrial septum •Absence of identifiable pulmonary venous drainage back to the heart •Reversal of flow seen in descending aorta in diastole •Right-to-left shunting in the patent ductus arteriosus in systole and diastole •Abnormal end-diastolic flow in pulmonary artery •Severe dilation and dysfunction of the right ventricle

Figure 6.

(Right) Modified high parasternal view in color-compare mode demonstrating reversal of flow in the left pulmonary artery at end diastole (white arrows). (Left) Pulsed-wave Doppler interrogation of the left pulmonary artery (LPA) showing the reversal of flow (white arrows). Ao, Aorta.

Discussion

Total anomalous pulmonary venous return with no connection is a rare congenital heart disease first reported by Lucas et al.¹ in 1962 using the term common pulmonary vein atresia. Newborns with this disease are extremely ill and present immediately after birth with severe pulmonary hypertension and poor cardiac output due to the lack of adequate blood flow into the left side of the heart. In a recent review article, Perez et al.² reported that newborns with this disease usually expire within 48 hours of birth. This critically ill patient had limited prenatal care, with no warning of this disease. However, even with fetal ultrasound prenatal detection, pulmonary venous anomalies remain challenging in the fetus because there is limited pulmonary venous flow in utero. The majority of patients with this type of congenital heart disease are usually not diagnosed until after birth. A recent study describing the current status of prenatal detection rates across the United States for a wide range of congenital heart defects found total anomalous pulmonary venous connection to be the lowest detected among all congenital heart defects at approximately 9%.³ In some cases, right ventricular dilation with an abnormal pulmonary venous confluence behind the atria can sometimes be identified prenatally and lead to a diagnosis, but the pulmonary veins are difficult to visualize on fetal echocardiography. Limited fetal diagnosis leads to an even higher responsibility to make the diagnosis after birth.

Total anomalous pulmonary venous return with no connection is characterized by lack of direct connection of a common chamber (confluence) of the pulmonary veins to the heart, portal system, or systemic venous system.² Echocardiography is useful in screening for this disease, although it lacks the ability to definitively diagnose the defect; in most cases of extracardiac total anomalous pulmonary venous connection, a vertical vein can be identified by echocardiography with a connection usually by way of a vertical vein to the portal system or the systemic venous system. In this case, echocardiography identified unique characteristics of total anomalous pulmonary venous connection without evidence of a patent vertical vein. Our inconclusive echocardiographic findings led to the need for additional imaging with a different modality. Cardiac catheterization has been reported to make this diagnosis in 70% of cases.² In this patient, the blind-ended pulmonary venous confluence was identified by angiography. In this disease, collateral vessels, which are usually bronchial veins, may be present because of the lack of pulmonary venous return. Indeed, these are often the only method of pulmonary venous drainage for these patients, but they are generally inadequate for long-term survival. In this patient, small connections to the bronchial veins were identified and allowed the patient to survive for a few hours. Only patients with larger collateral vessels have a chance for survival.⁴ Despite advances in congenital heart disease management, the prognosis for this condition remains extremely poor. Surgical options slightly improve in cases with a large common pulmonary venous confluence as the risk for confluence stenosis to the left atrium decreases. Perez et al.² also noted that the closer the left atrium to the confluence, the better the chance of survival, because of the shorter baffling to connect the confluence to the left atrium, reducing the chance of stenosis. However, Perez et al. found that mortality remained high, occurring in 40% of surgical attempts. Often, mortality is related to the irreversible damage to the pulmonary vascular bed.

The differential diagnosis of retrograde diastolic flow in the transverse arch includes severe aortic insufficiency, an arteriovenous malformation of the vein of Galen, hypoplastic left ventricle, and low cardiac output with cerebral vasodilation for brain-sparing effect. In this patient, the first three pathologies were readily ruled out by echocardiography and head ultrasound. Thus, it is likely that the reversal of flow in the transverse arch was a result of cerebral vasodilation in the setting of low cardiac output. Also observed by echocardiography was reversal of flow in the left pulmonary artery at end diastole, which has been previously reported as a sign of severe pulmonary vein stenosis⁵ (Figure 6, Video 6).

Figure 5.

Angiogram via hand injection in the right pulmonary artery (RPA) demonstrating the small pulmonary venous confluence on levophase.

Conclusions

Total anomalous pulmonary venous return with no connection is a rare disorder that often has a lethal prognosis. Clinical presentation occurs immediately at birth with severe, unrelenting cyanosis. Infants with this diagnosis can be mistakenly diagnosed with pulmonary hypertension of the newborn, which can lead to inappropriate management strategies. In this case, echocardiography upon arrival to the cardiac intensive care unit demonstrated all right-to-left atrial shunting, no evidence of pulmonary venous connection to the left atrium, suspicion of a pulmonary venous confluence behind the left atrium, and absence of a vertical vein connection or other systemic venous connection to allow egress of the pulmonary venous confluence. Also noted was a diminutive left atrium, large patent ductus arteriosus shunting almost entirely right to left, and retrograde diastolic flow in the transverse arch and reversed flow in the left pulmonary artery at end diastole. All of these echocardiographic findings eventually led to the appropriate diagnosis of total anomalous pulmonary venous return with no connection. This case also highlights that additional diagnostic modalities may be required when a complex pulmonary venous abnormality is suspected.

Supplementary Data

Video 1

Transthoracic echocardiography. Subcostal two-dimensional left anterior oblique view sweeping to demonstrate the small pulmonary venous confluence behind the heart. A blind-ended vertical vein is seen arising from the confluence.

Video 2

Transthoracic echocardiography. Subcostal left anterior oblique view with color Doppler demonstrating all right-to-left flow shunting across the atrial septum.

Video 3

Transthoracic echocardiography. High parasternal view (ductal view) using color Doppler demonstrating all right-to-left flow across the patent ductus arteriosus.

Video 4

Transthoracic echocardiography. Suprasternal sagittal view of aortic arch in color-compare mode demonstrating reversal of flow in the transverse aortic arch during diastole.

Video 5

Cardiac Catheterization. Angiogram via hand injection in the right pulmonary artery demonstrating the small pulmonary venous confluence on levophase.

Video 6

Transthoracic echocardiography. Modified high parasternal view, two-dimensional, and color Doppler demonstrating reversal of flow in the left pulmonary artery at end diastole.