Cerebral venous drainage through internal jugular vein

Internal jugular veins (IJVs) are the largest veins in the neck and are considered the primary cerebral venous drain for the intracranial blood in supine position. Any reduction in their flow could potentially results an increase in cerebral blood volume and intracranial pressure (ICP). The right internal jugular vein communicates with the right atrium via the superior vena cava, in which a functional valve is located at the union of the internal jugular vein and the superior vena cava. The atrium aspiration is the main mechanism governing the rhythmic leaflets movement of internal jugular vein valve synchronizing with the cardiac cycle. Cardiac contractions and intrathoracic pressure changes are reflecting in Doppler spectrum of the internal jugular vein. The evaluation of the jugular venous pulse provides valuable information about cardiac hemodynamics and cardiac filling pressures. The normal jugular venous pulse wave consists of three positive waves, a, c, and v, and two negative waves, x and y. A normal jugular vein gradually reduces its longitudinal diameter, as described in anatomy books; it is possible to segment IJV into three different segments J3 to J1, as it proposed in ultrasound US studies and CT scan. In this review, the morphology and methodology of the cerebral venous drainage through IJV are presented

Mechanical Function of Internal Jugular Vein Valve: Post-analysis of M-Mode Imaging under Cardiac Monitoring

Because the internal jugular vein (IJV) valve is the only protective valve between the brain and heart, recent studies have focused on the dynamic behaviour of the valve and its importance in regulating the cerebral blood outflow pathway. However, the mechanism underlying valve opening and closure, as well as the normal opening time, has not been investigated before. The aim of the study described here was to investigate IJV physiology in healthy young adults by means of ultrasound imaging. Twenty-four normal young adults (16 male, 8 female, 21.79 ± 0.79 y of age) were enrolled in this study. Each participant underwent IJV B- and M-mode ultrasound scans of the neck veins in supine position. Data on IJV leaflet movement and IJV blood velocity were extracted from images with the associated electrocardiogram traces to analyze the opening and closure cycles of IJV leaflets. The normal opening time calculated in this study includes 70% of the dynamic valve cycle. The normal opening time of the IJV valve could be a new physiologic metric and serves as a premise for further studies in the field of cerebral venous return