Compression of the left brachiocephalic vein between the aorta and the sternum – a new member of the family of midline compression and congestion syndromes

A 31-year-old male returned from a journey to Southeast Asia with multiple parasitic infections requiring antimicrobial treatment. At this time, he developed increasing pressure in his head and a prominent left internal jugular vein which disappeared when was in an upright position – sitting or standing, but became prominent when the patient the patient was lying down. He also developed congestion of the left arm, which was only visible when the patient was in an upright position and disappeared when he was lying down.

Detailed functional colour Doppler ultrasound revealed 2 compression syndromes that were dependent on body position. A compression of the left subclavian vein between the first rib and the clavicle, which developed only in the upright position – a positional thoracic inlet syndrome.

In this article, however, I will concentrate on the new compression syndrome, which belongs to the family of midline compression and congestion syndromes: The compression of the left brachiocephalic vein by the aorta against the sternum.

The sonographic examination video explains the sonographic findings in detail and highlights the specific midline location.

The second video correlates these sonographic findings with the CT venogram of the upper thoracic aperture .

The interesting fact that the congestion of the left internal jugular vein was dependent on the patient’s posture was explained by the presence of severe left renal vein compression. It has been shown that blood from the left renal vein enters the spinal canal, thereby putting pressure on the epidural plexus due to the influx of additional amounts of blood from the left renal vein into the spinal canal via the collaterals. Thus, the compression of the left cephalic vein co-exists with another midline compression syndrome – here the so-called nutcracker syndrome.

The relationship with positional congestion of the left jugular vein is as follows:

In the upright position, gravity pulls the blood in the collaterals of the left renal vein – the left spermatic vein and the epidural plexus – downwards. This allows the upper cervical epidural plexus to be used to drain the skull, as the collateral blood flow from the left kidney spares the upper thorax and skull.

In the horizontal position, the effect of gravity is now perpendicular to the spine and therefore has no effect on the distribution of collateral blood from the left kidney up and down the spine. (Even without such an additional influx, it is well known that intracranial pressure rises when lying horizontally because the cerebrospinal fluid and blood cannot easily leave the skull.)

The venous drainage of the skull is based on 3 venous drainage routes: The first is the jugular vein, the second is the epidural plexus and the third is the vertebral veins.

If congestion in the epidural plexus obstructs the outflow through this route, more fluid is forced into the internal jugular vein. The uptake of additional blood into the vertebral vein is limited because this vein passes through bony holes in the lateral processi of the cervical vertebrae. These bony rings do not allow significant distension of the vein.

Therefore, any pre-existing subclinical compression of the brachiocephalic vein must become clinically significant when the patient lies down.

Thus, the patient had a compression of the brachiocephalic vein which became relevant and showed a conspicuous distension of the left internal jugular vein once the patient was lying down.

It is possible that the multiple parasitic infections have triggered a strong immune response that required the recruitment of T (thymic)-lymphocytes. T-lymphocytes are processed in the thymus, an organ behind the breastbone that is large in early childhood but decreases in size during adulthood. However, the patient’s multiple infections may have activated the thymus, which then took up extra space behind the sternum, contributing to the development of the then visible compression of the left brachiocephalic vein, distension of the left internal jugular vein and very severe pressure in the left skull.