Partial anomalous left supracardiac pulmonary venous return

Clinical History

A 62-year-old male patient, complaining of chest pain, was referred to our radiology department to exclude pulmonary embolism.

Imaging Findings

MDCT examination was performed in an arterial phase after injection of 80 ml Imeron 300. Pulmonary embolism was excluded. Incidentally, only three of four pulmonary veins were connected to the left atrium. The fourth pulmonary vein, which drains the left upper lobe, was dilated and connected to the innominate vein through a vertical vein (see figures). The superior vena cava and the right side of the heart were dilated.

Discussion

Pulmonary veins are the vessels carrying oxygenated blood from capillary-alveolar interface to the left atrium [1]. Most individuals have 4 pulmonary veins, which drain into the left atrium.

During embryological development, when the left atrium/common pulmonary vein fails to connect to one or more of the tributaries of the primitive pulmonary vascular bed with persistent connection of these tributaries to the systemic circulation, through the cardinal or umbilicovitelline system, will lead to persistent pulmonary systemic connection [2]. When all four pulmonary veins fail to connect to the left atrium the condition is called total anomalous pulmonary venous return (TAPVR). Partial anomalous pulmonary venous return (PAPVR) is the condition, where connection fails in one or more, but not all veins.

Our patient is an example of PAPVR, which forms about 0.5% of cases of congenital heart diseases [3]. It is classified according to the level of the drainage of the anomalous vein into supracardiac, cardiac and infracardiac [4]. In 90% of cases these anomalies are associated with ASD [5, 6]. PAPVR with a single anomalous vein has no significant effect on the haemodynamics and is usually discovered incidentally [7]. Symptomatic cases are usually due to associated conditions such as ASD [2].

Echocardiography is generally the first investigation of choice in the evaluation of congenital heart diseases. It is helpful in the detection of associated anomalies, such as ASD, but visualization of the anomalous vein is difficult. Conventional angiography can show the anomalous vein but this is an invasive procedure and therefore superseded by cross sectional imaging, that allows visualization of the anomalous vein connected with the systemic circulation. A better delineation may be achieved by using post-processing techniques like MIP and 3D-volume rendering. CT has an accuracy approaching 100% [8]. MRI has the advantage of not using ionizing radiation, and having a sensitivity of 95% [9]. It can also detect ASD and help in evaluation of cardiac function [10].

Most patients with PAPVR do not require surgery [11]. Surgery can be considered in the following situations: Significant left to right shunt with a pulmonary to systemic flow ratio of more than 2:1; cardiomegaly on chest X-ray or right ventricular hypertrophy on ECG; in recurrent chest infections (as in scimitar syndrome); if compression of surrounding structures exists; or if any surgical cardiac repair is planned for other reasons, such as ASD [12].

PAPVR has an excellent prognosis with good post-operative results in asymptomatic patients.

Differential Diagnosis List

Final Diagnosis

Partial anomalous left upper pulmonary venous return.

URL:	https://www.eurorad.org/case/11405
DOI:	10.1594/EURORAD/CASE.11405
ISSN:	1563-4086