S. Sala, R. Rizzati, A. Giombi, M. Rollo, R. Galeotti
Patient
female, 65 year(s)
Clinical History
The patient was referred for a chest CT examination because of an abnormal vascular structure near the left atrium seen on echocardiography performed in the investigation of hypertension.
Imaging Findings
The patient was referred for a chest CT examination because of an abnormal vascular structure near the left atrium seen on echocardiography performed in the investigation of hypertension.
The CT scan showed left superior vena cava persistence with absence of the left brachiocephalic vein.
Discussion
Persistent left superior vena cava (LSVC) may be observed in 0.3% of unselected cases and is the most common thoracic venous anomaly. It forms from a confluence of the left subclavian and left jugular veins and courses inferiorly in a position analogous to the normal right superior vena cava.
Inferiorly, the left superior vena cava lies anterior to the left hilum and drains into a dilated coronary sinus. Its anatomical course reflects its origin as a persistent remnant of the left anterior cardinal vein, a vessel that is present in early embryological development but normally disappears.
A right superior vena cava may or may not be present, while the left brachiocephalic vein is usually absent, as in this case. If it is not associated with other congenital cardiac anomalies, left superior vena cava is usually asymptomatic. Its diagnosis can be confirmed by many noninvasive and invasive tests like echocardiography, angiography and computed tomography. Magnetic resonance (MR) imaging has been reported as a useful tool for delineating both the thoracic venous and associated intracardiac anomalies; howerever, in our experience, CT with currently available 3D volume rendering reconstructions allows correct diagnosis of this vascular anomaly, avoiding more invasive tests.
Final Diagnosis
Persistent left superior vena cava
MeSH
Vena Cava, Superior
[A07.231.908.949.815]
The venous trunk which returns blood from the head, neck, upper extremities and chest.
Cardiovascular Abnormalities
[C14.240]
Congenital structural abnormalities of the cardiovascular system.
CT scan at the level of the aortic arch shows the presence of right and left superior vena cava posterior to the sternum. Absence of the left brachiocephalic vein may be observed.
CT scan at the level of left hylum shows the left superior vena cava passing anterior to the left pulmonary artery.
At the level of the heart, this CT scan shows the left superior vena cava passing lateral to the left atrium, directed towards a dilated coronary sinus.
Figure 2
Volume rendering reconstruction
3-dimensional reconstruction of the spiral CT data set shows the characteristic appearance of the left superior vena cava and its course in the left side of the mediastinum.
Figure 1
Angio CT of the chest
Figure 1a
CT scan at the level of the aortic arch shows the presence of right and left superior vena cava posterior to the sternum. Absence of the left brachiocephalic vein may be observed.
Figure 1b
CT scan at the level of left hylum shows the left superior vena cava passing anterior to the left pulmonary artery.
Figure 1c
At the level of the heart, this CT scan shows the left superior vena cava passing lateral to the left atrium, directed towards a dilated coronary sinus.
Figure 2
Volume rendering reconstruction
3-dimensional reconstruction of the spiral CT data set shows the characteristic appearance of the left superior vena cava and its course in the left side of the mediastinum.
