Abstract:
internal jugular vein valve (IJVV), which is situated just above the
termination of the internal jugular vein, is the only valve between the heart and the
brain. This means that it plays a role in the prevention of cephalad flow of venous
blood. If the IJVV is damaged or becomes incompetent, increase in intrapleural
pressure could result in raised intracranial pressure. Additionally, the jugular venous
pulse (JVP) is used clinically to estimate right atrial pressure, a functional IJVV may
prevent accurate estimation of the JVP.
Objectives: To describe the presence and the competence of the IJVV in post-mortem
and live human subjects.
Design – setting and methods: The anatomical appearance of the IJVV from 30 cadavers
was studied. Competence was checked by measuring maximum hydrostatic pressure
before reflux occurred through the valve. The function of the valve was evaluated in
25 live subjects using colour duplex scanning.
Results: The IJVV was present in all cadavers just before its termination (60 IJVVs
from 30 subjects). The valve was bicuspid in most cases (93%). The competence of
41 IJVVs was checked of which only three (7%) were found to be incompetent. All
IJVVs in live subjects were found to be competent.
Conclusion: This study confirms that a functional IJVV is present just above the
termination of the internal jugular vein. The IJVV may therefore prevent reflux of
venous blood from the right atrium into the internal jugular vein.
