DISTRIBUTION AND MORPHOLOGY OF VALVES IN THE HUMAN EXTERNAL JUGULAR-VEIN - INDICATIONS FOR UTILIZATION IN MICROVASCULAR ANASTOMOSIS

Purpose: This study examined the valves in the external jugular vein ( EJV) that could affect microvascular anastomosis and increase the risk of thrombogenesis. Materials and methods: The EJVs of 57 sides from 3 6 cadavers aged 40 to 95 years (20 males and 16 females) were dissecte d. After opening the veins, the distribution and morphology of the val ves were investigated using a stereoscopic microscope. The length of t he valves and inner diameter of the vessels were measured and related to the location of the valves. Results: Forty-nine (86%) of 57 EJVs we re confluent with the subclavian vein. The EJV possessed bicuspid valv es, and in 46 (93.9%) of the 49 specimens there were valves at the jun ction with the subclavian vein, whereas 44 (89.8%) contained valves in the middle portion of the specimen. The length of the valves was less than twice the inner diameter, and some were occasionally only rudime ntary. Conclusion: Numerous valves exist in the middle portion of the EJV where microvascular anastomoses are performed. When valves are obs erved in the site of anastomosis, they can be avoided by resecting a l ength equal to approximately twice the inner diameter.