Persistent jugulocephalic vein: case report including commentaries on distribution of valves, blood flow direction and embryology.

This paper is a detailed case study of the persistent anastomotic channel between the cephalic vein and the external jugular vein, running anterior to the clavicle, corresponding to the jugulocephalic vein present at early stages of the ontogenesis in humans. This connection is not only a relic of early foetal development seldom occurring in adults, but it may also be of clinical significance, increasing the risk of complications during the cephalic vein catheterisation, clavicular fractures or head and neck surgery. The novelty in this paper was to determine the presence and distribution of valves within the persistent jugulocephalic vein. Three bicuspid venous valves were found that allowed the blood to flow only in one direction - from the cephalic vein to the external jugular vein. The anastomosis between the persistent jugulocephalic vein and the thoracoacromial veins was additionally present. Due to lack of similar data in the literature, further research should be performed on the presence and distribution of the venous valves in various types of the persistent jugulocephalic vein in humans.