title: Internal jugular vein and carotid artery anatomic relation as determined by ultrasonography.
abstract: BACKGROUND
  Cannulation of the internal jugular vein (IJV) is associated with a 95% success rate when external landmarks are used. Anatomic variability has been implicated as the cause for difficulty in cannulation without ultrasound. In contrast to an IJV located lateral to the carotid artery (CA), an IJV overlying the CA may result in CA puncture. The authors' purpose in this study was to examine, using ultrasound, the anatomic relation of the IJV and CA as viewed from the perspective of a cannulating needle.
  
  
  METHODS
  Ultrasound imaging was used in 1,136 patients to examine the relation between the IJV and CA. A 7.5-MHz transducer was placed in the direction of a cannulating needle on the right neck at the apex of the angle formed by the division of the sternocleidomastoid muscle. A Polaroid photograph of the image was later scored by three blinded investigators according to the percentage of the CA overlaid by the IJV (0 to 4).
  
  
  RESULTS
  Of the 1,136 Polaroid photographs of the ultrasound images, 1,009 were suitable for scoring. Fifty-four percent of all patients received a score of 4, which indicated that the IJV overlies more than 75% of the CA in an imaging plane positioned in the direction of a cannulating needle. Patients older than 60 yr were more likely to have this anatomy than patients younger than 60 yr (P < 0.05). None of the other patient characteristics recorded were predictive of this anatomic relation.
  
  
  CONCLUSIONS
  In a majority of patients, the IJV is not lateral to the CA in an ultrasound imaging plane positioned in the direction of a cannulating needle. Instead, the IJV overlies the CA in 54% of patients overall, predisposing these patients to CA puncture if the cannulating needle traverses the IJV.
authors.affiliation: Department of Anesthesiology, Mercy Hospital of Pittsburgh, Pennsylvania 15219, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Troianos
authors.forename: R J
authors.initials: RJ
authors.lastname: Kuwik
authors.forename: J R
authors.initials: JR
authors.lastname: Pasqual
authors.forename: A J
authors.initials: AJ
authors.lastname: Lim
authors.forename: D P
authors.initials: DP
authors.lastname: Odasso
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002339:Carotid Arteries / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D002405:Catheterization, Central Venous; D006801:Humans; D007601:Jugular Veins / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D008875:Middle Aged; D014463:Ultrasonography