Venous Access — Internal Jugular

Origin / Course / Termination

• Originates at the jugular foramen where it continues the sigmoid sinus
• Exits the foramen accompanies by the glossopharyngeal (IX), vagus (X) and accessory (XI) nerves
• runs caudally down the neck – The vein lies most superficially in the upper part of the neck
• The vein lies lateral, first, to the internal carotid artery, separated by the hypoglossal (XII) nerve, and then to the common carotid artery, with the vagus nerve between and posterior to the artery and vein.
• These three structures lie in a common fascial compartment (the carotid sheath) with the cervical sympathetic chain lying posterior to the sheath.
• These four structures, two vessels and two nerves, form a quartet throughout the neck.
• The deep cervical chain of lymph nodes lies close against the carotid sheath
• The vein is initially posterior to, then lateral and then anterolateral to the carotid artery during its descent in the neck
• Terminates behind the sternoclavicular joint, where it joins the subclavian vein to form the brachiocephalic vein 

Relations of the IJV

• Anterior –
  • Internal carotid artery and vagus nerve
  • Superficially, the internal jugular vein is overlapped above and then lower down covered by the sternocleidomastoid muscle and is crossed above by the posterior belly of the digastric and lower down by the inferior belly of the omohyoid
• Posterior –
  • C1, sympathetic chain, dome of the pleura. On the left side, the IJV lies anterior to the thoracic duct
  • Posteriorly, the vein rests on (from above downwards) the rectus capitis lateralis, the transverse process of the atlas, the scalenus medius, and the scalenus anterior, with the phrenic nerve crossing it; and all are covered by the precervical fascia
• Medial – Carotid arteries, cranial nerves IX-XII

Surface Anatomy for Venepuncture

• Lies lateral to the carotid artery within triangle formed by: Two heads of Sternocleidomastoid muscle and clavicle
• On Ultrasound: Non-pulsatile, thin walled, compressible vessel lateral to the carotid artery

Anatomical Variations

• The right IJV (80.5%) was more often larger than the left IJV.
• With reference to the CCA, 85.2% of the IJV were found in the lateral position, 12.5% anteriorly, 1.1% medially and 1.1% posteriorly.
• IJV were sometimes found to be hypoplastic, and in rare cases this was seen bilaterally in both the right and left IJV.
• 5.5% have an IJV that does not correspond to the site predicted by external markings
• Other variations:
  • IJV bifurcation
  • IJV duplication
  • IJV fenestration
  • IJV trifurcation
  • Posterior tributary

Sources:
Ellis H. The clinical anatomy of the great veins of the neck. Br J Hosp Med (Lond). 2010 Feb;71(2):M20-1. doi: 10.12968/hmed.2010.71.Sup2.46501. PMID: 20220708.
Asari AIA, Barros RAV, Borges MAP. Anatomic variant of the internal jugular vein and its importance in vascular access for hemodialysis. J Vasc Bras. 2019 Oct 23;18:e20190014. doi: 10.1590/1677-5449.190014. PMID: 31692937; PMCID: PMC6822959.

Gladwin / JC 2020

Answer by Gladwin, JC