valves and echo-doppler

[jean-la-grenouille]

Dear Dr Sclafani,

I wish you an exciting new year and thank you for your commitment to MS sufferer.

I have 2 simple questions (sorry if this as already been discussed) :

1)are there valves in the internal jugular veins ?
I have been told by a french vascular surgeron, that blood flow doesn't need valves because it's not opposed to gravity.

2)I don't know much about the technique (IVUS) you use to diagnose CCSVI. Does an echo-doppler, performed by a competent doctor, provide enough information to check for CCSVI ?

[Cece]

http://www.thisisms.com/forum/chronic-c ... -6255.html

There is the link to Dr. Sclafani's thread. Your question has landed in the main CCSVI forum, but he's been known to find questions out here as well.

I'd love to see more questions, if anyone has any. It has always been an honor that Dr. Sclafani has maintained a presence here, and a tremendous resource as well.

[jean-la-grenouille]

Thanks Cece, I made a mistake when I sent my Post....I put the topic in the right place.

[1eye]

Usually there are valves in the internal jugulars. As many as 10% of people may have none. If a vein is above the heart, and the person is upright, gravity will help get blood back to the heart and lungs. If it is below the heart, muscles alongside it will squeeze the blood upward, which the veins allow more easily than the arteries, because they are more flexible, having thinner walls, with less of their own smooth muscle to make them stiff. If a vein is below the heart and must get blood upward, against gravity, the valves inside the vein can keep gravity from pulling the blood back down. If you stand on your head, the valves below your heart don't help anymore, and gravity does the work, but the ones in your neck will protect your brain. Perhaps we have lost the neck ones sometimes, in evolution from primates, because they help most when you are upside-down, and we don't hang upside-down from trees as much anymore.

The smooth muscle, inside the vein, is for adjusting the diameter of the vein, not moving the blood. The squeezing action that moves the blood upward, against gravity, is done by external muscles, like in the legs and chest. I think the heart does not bring blood upwards from below it, against gravity, or downwards from above, since it has enough work to pump blood away from itself, to the organs and lungs. It relies on gravity to get blood from above, and other muscles to bring the blood back from below. Valves keep blood from falling or going backward.

Or so I believe. Your mileage may vary.