Observation on Azygos System in 78 Chinese Adults / 第三军医大学学报

ABSTRACT

The azygos system was studied on 78 Chinese adult cadavers. The occurrence of the type of coexisted azygos, hemiazygos and accessory hemiazygos veins is 64.10%. The components of hemiazygos and accessory hemiazygos veins are sub- ject to such a large variation that the division of the azygos system into three major trunks is not always practicable since no generally-agreed criterion can be observed. The authors, according to Seib's suggestion! classify the azygos system into three types, that is, the double trunk, the intermediate, and the single trunk types, based on the condition of the interruptions of the hemiazygos. system Intermediate type occurs most frequently and its occurrence is 52.56% in this series.The interruptions of the hemiazygos system and the communications between azygos vein and hemiazygos system are far more numerous in Chinese than in Caucasians. The racial difference of the azygos system between Chinese and Caucasian subjects suggests that the azygos system of the Caucasians more likely belongs to the embryonic type. The middle segment of the azygos vein runs to the left of the midline in adults, and the origin of the azygos system usually connects with the inferior vena cava or the renal vein.The findings mentioned above might arouse the interest or the attention of the clinicians.