Previous Next Home


This classification system of internal jugular vein zones of compression was then developed. The area of compression that is most likely causing most of the symptoms is Zone I at the mid-neck between the SCM and carotid artery. The other areas may very well be additive, or even primary in some individuals, and as will be seen, this anatomy is highly variable. Zone I compression is confirmed on our ultrasound studies, Zones II and III are hypothesized based on anatomic review, and both of these areas may be a secondary source of compression as the release of gravitational load on the thoracic viscera allows recoil in a cranial direction, putting additional volume and tissue pressure at the apex of the lung, which rises above the level of the clavicle into the neck. Zone IV compression has been shown to occur in MRI studies during cardiovascular procedures in the literature.

But once again, Zone I is the main culprit.

In the initial abstract, prior to obtaining the ultrasound unit, I thought it was Zone II compression at the clavicle due to release of the gravitational load on the lungs with compression of the IJ. With ultrasound study, it became immediately clear that the level was Zone I.