Vol 62, No 4 (2003)
Short communication
Published online: 2003-09-05
Variability of the azygos vein system in human foetuses
Folia Morphol 2003;62(4):427-430.
Abstract
The aim of the study was to examine the variability of the azygos vein system
and to determine the location of the veins with reference to the vertebral midline
and the skeletopy of their termination. The research material consisted of
32 human foetuses (14 male, 18 female) from 21st to 24th week of intrauterine
life, fixed in 10% neutral formalin solution. Conventional anatomical - radiographic
methods were used. 5 different configurations of the azygos vein system
were found. In the 1st configuration there were 3 azygos veins, with both
the left side veins, the hemiazygos vein (HV) and the hemiazygos accessory vein
(HAV), joining the azygos vein (AV) separately. In the 2nd configuration the HV
and the HAV were joined to the AV together. In the 3rd configuration the HAV
was missing, and the 4th to 8th left intercostal veins were joined to the AV separately.
In the 4th configuration the HV was missing. In the 5th configuration
there was the AV only, which coursed along the vertebral midline. In these
4 configurations (1–4) the AV was located on the right side (90.6%) and in the
5th configuration the AV was located in the vertebral midline. The termination
of the AV projected mostly on Th4 (81.25%). The junction of the HV and the AV
was found the most frequently at Th8 (35.7%), and the junction of the HAV and
AV most frequently at Th4 (41.6%).
Keywords: azygos veinhemiazygos veinhemiazygos accessory veinhuman configurationfoetuses