Congenital Pulmonary Artery Anomalies: A Review and Approach to Classification

Abstract

Congenital pulmonary artery anomalies are infrequent but given improved prenatal diagnosis and care, and neonatal surgical advances, over the past two decades are not uncommonly encountered by cardiothoracic imagers. An understanding of their etiology, classifications, associated anomalies, and surgical management can be helpful to avoid under or overdiagnosis. Timely diagnosis assisted by familiarity with imaging findings across modalities and recognition of surgical findings allows for medical management and surgical planning for these patients, with more patients reaching adulthood than ever before.

Keywords: Anomalous origin of a branch pulmonary artery from ascending aorta; left pulmonary artery sling; main pulmonary artery; right pulmonary artery; unilateral pulmonary artery agenesis.

Figure 1

A 39-year-old female with a history of congenital heart disease, which included atrial septal defect and right pulmonary artery stenosis. The patient underwent atrial septal defect repair and angioplasty of the pulmonary artery. Pulmonary artery and lateral radiographs of the chest show enlargement of the pulmonary trunk and left pulmonary artery (black arrow) in a patient with congenital pulmonary artery stenosis.

Figure 2

The same patient as in Figure 1. 3D reconstruction and axial computed tomography angiogram shows severe short-segment discrete narrowing of the proximal right pulmonary artery (black arrows).

Figure 3

A 3-day-old female with a history of cardiac abnormalities and symptomatic respiratory distress. Computed tomography angiogram images (a and b) are selected axial images, (c) is a coronal reconstruction, and (d) is a sagittal reconstruction. The main and left pulmonary artery opacify with contrast (white arrowhead). The right pulmonary artery is absent (white arrows demonstrate expected location). No large major aortopulmonary collateral arteries from the aorta or major branch vessel was identified in this patient. There is an incidental azygous lobe noted in the right lung.

Figure 4

Computed tomography angiogram [same patient as Figure 3] demonstrating poor contrast opacification of the distal right pulmonary artery in the right lower lobe (white arrow). The right pulmonary veins are also small in caliber (white arrowhead).

Figure 5

A 5-day-old term infant with prenatal concern for truncal abnormality. Axial images [Figure 5a to c] from a cardiac computed tomography angiogram demonstrating Type I truncus arteriosus with arch interruption. The aorta (black arrow) and main pulmonary artery (white arrow) are shown to arise from a common trunk (black arrowhead). The branch pulmonary arteries both arise from the posterior aspect of the common trunk (white arrows).

Figure 6

Coronal (a) and sagittal (b) reconstructions from the same computed tomography angiogram of the chest presented in Figure 5. The common trunk of aorta and main pulmonary artery (white arrow) are demonstrated as well as interruption of the aortic arch proximal to the origin of the left subclavian artery (black arrow).

Figure 7

Coronal images from a cardiac computed tomography angiogram in a 7-day-old male with Type II truncus arteriosus which was suspected on echocardiography. There is a dilated ascending aorta (black asterisk) with the branch pulmonary arteries arising separately from the posterior wall of the ascending aorta (right pulmonary artery = black arrow; left pulmonary artery = white arrow).

Figure 8

A 31-year-old patient with suspected connective tissue disorder. Axial computed tomography angiogram image from a young adult patient shows idiopathic dilatation of the left pulmonary artery (white arrow) with normal caliber main and right pulmonary artery.

Figure 9

Axial true fast imaging with steady-state free precession from the same patient in Figure 8 showing dilated main pulmonary artery (white arrow) which measured up to 6.4 cm in diameter. The branch pulmonary arteries are also dilated.

Figure 10

Axial images and 3D reconstruction of the heart from a cardiac computed tomography angiogram in a 6-day-old male. The right pulmonary artery (black arrow) arising from the ascending aorta. The main pulmonary artery (white arrow) is separate from the aorta (black asterisk). The left pulmonary artery arises from the main pulmonary artery.

Figure 11

Lateral esophagram on a patient with upper airway symptoms demonstrates an anterior impression, which can be seen with underlying anomalous left pulmonary artery (black arrow) between the airway (white arrow, outlined by an air column) and esophagus (white arrowhead).

Figure 12

Computed tomography angiogram of a 9-month-old male with prenatal concern for complex congenital heart disease and suspected left pulmonary sling on echocardiogram. Figures 12a to e are selected axial images demonstrating the anomalous origin of the left pulmonary artery (white arrow) from the right pulmonary artery (black arrow) as well as the abnormal posterior course of left pulmonary artery behind the trachea.

Figure 13

Images from the same patient in Figure 13. Computed tomography angiogram shows the aberrant left pulmonary artery (black and white arrows) courses between the lower trachea and the mid-esophagus causing moderate tracheal stenosis. Figure 13b and c are 3D reconstructions of the computed tomography angiogram better demonstrating the pulmonary sling.