The paediGAV is the world's first gravitational valve for the treatment of hydrocephalus in children. The valve is made of titanium, a material that guarantees outstanding precision, reliability and biocompatibility. The paediGAV is 3 Tesla MRI-conditional and is unaffected by subcutaneous pressure.
Upper depiction shows a schematic cross-section of the paediGAV. It is composed of a robust titanium casing whose proximal end contains a ball-cone valve. A spiral spring controls the opening pressure of the ball-cone valve. The gravity valve at the distal end consists of a tantalum ball that controls the opening pressure of the gravitiy valve, and a sapphire ball that ensures reliable closure and seating of the gravity valve.
When the child is supine, the ball-cone unit of the paediGAV controls the intraventricular pressure (IVP). The freely moving balls in the gravitational unit do not provide any resistance when the child is supine, and therefore the flow channel is always open in this position. The ball-cone valve is closed however, thus preventing any drainage, shown on the left depiction. If the patient's IVP increases and continues to rise, the spring pressure of the ball-cone unit will eventually be overcome and the sealing ball will move away from the cone. Now the paediGAV is open and CSF can flow, shown on the right depiction.
As soon as the patient stands up, the gravity valve closes and fluid drainage is interrupted. This prevents overdrainage effectively. Fluid drainage resumes only once the intraventricular pressure exceeds the sum of the opening pressures of both the ball-cone and gravitational units.