Azygography in the pre-treatment evaluation of oesophageal carcinoma.

Azygography is a useful technique for the pre-operative detection of unresectability of oesophageal malignancies. Invarison of the azygos vein by oesophageal carcinoma occurs because of the anatomic proximity of the thoracic oesophagus and the azygos vein. Azygography may be performed by either intraosseous injection of a rib or by direct retrograde catheterization. Complete obstruction of the azygos vein indicates that an oesophageal carcinoma is unresectable if no other intrathoracic disease is evident.