Masui. The Japanese journal of anesthesiology
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Although internal jugular vein cannulation is performed commonly, most physicians are not aware of existence of the internal jugular venous valve. This is the only valve between the right atrium of the heart and the brain, and it has an important role of preventing retrograde blood flow and increased back pressure to the brain. In this study, anatomic appearance of human internal jugular valves is described, and the competence of these valves is assessed. ⋯ The opening and closing of the valve were easily visualized with both superfine fiberscope and real-time ultrasound technique. Patients with competent valves showed transvalvular pressure gradients of 50-100 mmHg during cough-induced high intrathoracic pressure. Internal jugular venous valve is located 0.5-2.0 cm above the union of the subclavian and internal jugular veins, and the central approach performed at the summit of the cervical triangle has been shown to have a risk of injuring the internal jugular venous valve.(ABSTRACT TRUNCATED AT 250 WORDS)