azygous
adjective anatomy specialized uk/əˈzaɪ.ɡəs/ us/eɪˈzaɪ.ɡəs/
（肌肉、静脉等）不成对的，非一对中之一的，单一的
(of any structure in the body) existing as a single structure, not part of a pair
If the obstruction is above the entry of the azygous vein, the syndrome is less pronounced. 如果梗阻位于奇静脉入口上方，症状则会表现得相对不明显一些。