title: Distribution and morphology of valves in the human external jugular vein: indications for utilization in microvascular anastomosis.
abstract: OBJECTIVE
  This study examined the valves in the external jugular vein (EJV) that could affect microvascular anastomosis and increase the risk of thrombogenesis.
  
  
  METHODS
  The EJVs of 57 sides from 36 cadavers aged 40 to 95 years (20 males and 16 females) were dissected. After opening the veins, the distribution and morphology of the valves were investigated using a stereoscopic microscope. The length of the valves and inner diameter of the vessels were measured and related to the location of the valves.
  
  
  RESULTS
  Forty-nine (86%) of 57 EJVs were confluent with the subclavian vein. The EJV possessed bicuspid valves, and in 46 (93.9%) of the 49 specimens there were valves at the junction 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 rudimentary.
  
  
  CONCLUSIONS
  Numerous valves exist in the middle portion of the EJV where microvascular anastomoses are performed. When valves are observed in the site of anastomosis, they can be avoided by resecting a length equal to approximately twice the inner diameter.
authors.affiliation: Kagawa Medical School, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Nishihara
authors.forename: Y
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: M
authors.initials: M
authors.lastname: Miyake
authors.forename: S
authors.initials: S
authors.lastname: Nagahata
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000714:Anastomosis, Surgical / Q000379:methods; D002102:Cadaver; D005260:Female; D006801:Humans; D007601:Jugular Veins / Q000033:anatomy & histology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged