Objective: Internal jugular valves are the only venous valves between the heart and the brain. Conditions such as coughing and other precipitating activities may result in retrograde cerebral venous flow because of the absence or presence of internal jugular valve incompetence, allowing brief transmission of high venous pressure and resulting in brain disturbance. Knowledge of these valves and their noninvasive evaluation might be useful in clinical practice.
Methods: We applied air contrast ultrasonographic venography to a large sample of healthy subjects (n = 125) to evaluate the ultrasonographic aspects of internal jugular valves and their competence.
Results: The valves were observed in 121 (96.8%) of 125 subjects and were present bilaterally in 107 (85.6%) and unilaterally in 14 (11.2%). In 4 subjects we did not detect the valves. Retrograde venous flow was present in 48 (38.4%) of 125 subjects. The frequency of internal jugular valve incompetence was significantly higher on the right side (36 [30.2%] of 119) than on the left (7 [6.4%] of 109; P < .0001). Retrograde venous flow due to incompetence of jugular valves was significantly more frequent at older ages (<50 years, 20%; and > or =50 years, 38.75%; P < .03) and was more frequent in men (33 [25%] of 132) than in women (10 [10.41%] of 96; P < .02).
Conclusions: Air contrast ultrasonographic venography is a noninvasive method for evaluating internal jugular valves and identifying retrograde venous flow. This information may be useful in clinical and interventional care.