Internal Jugular Vein
Describe the anatomy relevant to central venous access (including
femoral,internal jugular, external jugular, subclavian and peripheralveins)
The internal jugular vein:
- Originates at the jugular bulb
This is a dilatation formed by the confluence of the inferior petrosal sinus and the sigmoid sinus.
- Exits the skull via the jugular foramen
- Descends laterally to the internal carotid (and later the common carotid) in the carotid sheath
- Teminates behind the sternal end of the clavicle, where it joins with the subclavian vein to form the brachiocephalic vein
- Anteriorly by SCM
- Posteriorly by the lateral mass of C1, scalene muscles, and lung pleura
- Medially by the internal carotid
- Vagus nerve lies behind/between the carotid and IJV
- Cervical sympathetic plexus lies posterior to the carotid sheath
- Deep cervical lymph nodes lie close to the vein
- External jugular crosses the sternomastoid belly of SCM, running posteriorly and more superficial to the IJV, later perforating deep fascia to drain into the subclavian vein
- Pleura rises above the clavicle, and is close to the vein at its termination
- Thoracic duct passes lateral to the confluence of the left IJV and SCV, and may be injured during left IJV cannulation
- The right lymphatic duct may be injured during right IJV cannulation, but due to its smaller size this is less common
Identify the triangle formed by the two heads of SCM and the clavicle. Palpate the artery, and ensure the site of entry is lateral to the carotid. Aim:
- Caudally, at a 30 angle to the frontal plane
- Parallel to the sagittal plane
- Towards the ipsilateral nipple
Identify the vein deep to SCM, noting that it is (unlike the adjacent ICA):
- Thin walled
At the medial border of SCM, 3-4cm above the clavicle. Requires retraction of the carotid medially.
- Central approach
At the apex of the triangle formed by each muscle belly of SCM and the clavicle.
- Posterior approach
At the posterior edge of SCM, just superior to where the EJV crosses the sternomastoid.