Catheterization and roentgen visualization of the azygos vein and its tributaries in Laennec's cirrhosis. A new technic.

Abstract

The azygos system of veins normally drains the posterior chest and abdominal walls, the spine, and part of the bronchial circulation and mediastinal structures, including the esophagus and pericardium. It originates in the ascending lumbar veins, communicates with the inferior vena cava, renal veins, or both, and empties into the superior vena cava. It has many normal variations and may take over most or all of the functions of either vena cava in certain congenital anomalies and in cases of obstruction (1, 8, 1.5). The sacral plexus, lumbar veins, and the veins and plexuses of the spinal column and skull form a continuous extracaval channel which may be the path of metastases from pelvic tumors to spine and skull (2, 4). This venous reservoir is drained to a greater or lesser degree by the azygos vein. When the portal circulation becomes obstructed, an important alternative path for return of portal blood to the systemic circulation is via esophageal veins, to the azygos vein, and thence to the superior ...