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SVC obstruction

July 8, 2011 at 22:28 Leave a comment

Classification based on location of SVC obstruction
Pre-azygous or supra-azygous

Obstruction of blood return above the entrance of azygous vein into the SVC, resulting in venous distension and oedema of the face, neck, and upper extremities.

Post-azygous or infra-azygous

Obstruction below the entrance of azygous vein into the SVC results in retrograde flow through the azygous via collaterals to the inferior vena cava, resulting in not only the symptoms and signs of pre-azygous disease, but also dilation of the veins over the abdomen.

This is usually more severe and poorly tolerated than pre-azygous obstruction.

Entry filed under: ANATOMY.