The present study was motivated by the importance of the thyroid veins in
surgery in the anterolateral cervical region, particularly in tracheostomies, the
need for information on modern diagnostic imaging techniques and the lack
of specific publications on the subject. The research was performed on 30 adult
human specimens by means of dissection and measurement. The superior thyroid
vein was constant, single on both sides (83.3%), with its termination (87.1%)
at the internal jugular vein (97.2%), either isolated (29.4%) or with other veins,
mostly the lingual vein (52.1%), and was located between 1.0 and 2.5 cm
below a plane that passes the upper margin of the hyoid bone. The medial
thyroid vein, when present, was not constant (43.3%), was single (96.1%),
terminated in the internal jugular vein and was located between 2.0 and 4.0 cm
from the mid-sagittal line (84.6%). The inferior thyroid vein was constant (96.7%)
and varied in number, with one (62.1%), two (27.6%) or even five occurring,
and was formed by the confluence of two primary branches (78.6%) as a result
of the abundance of anastomoses coming from the lower and medial parts of
the gland. The number of terminations corresponded to the number of veins,
at the level of the 5th to 8th rings in 36.9%, of the 9th to 10th rings in 34.8% and
of the 11th to 14th rings in 28.3%, and occurred in the right brachiocephalic
vein (26.1%), in the left brachiocephalic vein (60.9%) or in both veins (13.0%)
