[Valve injury: a new complication of internal jugular vein cannulation].

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. We examined also a safe approach to percutaneous cannulation of the internal jugular vein to avoid this complication. In the cadaveric subjects, the internal jugular vein with its valve was removed at the time of autopsy. In the living subjects, to examine the movement of this valve, endoscopic visualization utilizing the superfine fiberscope, and ultrasound techniques were applied. Next, to detect the competence of the jugular venous valve, transvalvular pressure gradients were measured. Nineteen internal jugular valves were obtained from 20 cadaveric subjects. These valves were situated directly above the termination of the internal jugular vein into the inferior bulb. 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)