Anatomic and pathophysiologic studies of the human internal jugular valve.

The results of anatomic and hemodynamic studies of the human internal jugular valve, which is the only venous valve between the right atrium of the heart and the brain, have been reported. Tricuspid internal jugular valves were present in two cadaver subjects without any observed compromise in competency. Most valves tested were competent, with the exception of those from one cadaver which were apparently congenitally incompetent. Acquired or congenital internal jugular valve incompetence may impair cerebral venous return, especially when intrathoracic pressure is increased by positive-pressure ventilation. Screening for internal jugular valve incompetence with a Doppler flowmeter before utilizing this type of mechanical ventilation may help prevent the deleterious effects of cerebral venous congestion.