The vertebral venous plexuses

A forum to discuss Chronic Cerebrospinal Venous Insufficiency and its relationship to Multiple Sclerosis.

The vertebral venous plexuses

Postby Cece » Mon Oct 15, 2012 10:46 am

http://lib.bioinfo.pl/pmid:21976364
Clin Anat. 2012 Jul ; 25(5):609-18 21976364

The vertebral venous plexuses: The internal veins are muscular and external veins have valves.

Mark D Stringer, Matthew Restieaux, Amanda L Fisher, Brynley Crosado
Department of Anatomy, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand.

The internal and external vertebral venous plexuses (VVP) extend the length of the vertebral column. Authoritative sources state that these veins are devoid of valves, permitting bidirectional blood flow and facilitating the hematogenous spread of malignant tumors that have venous connections with these plexuses. The aim of this investigation was to identify morphologic features that might influence blood flow in the VVP. The VVP of 12 adult cadavers (seven female, mean age 79.5 years) were examined by macro- and micro-dissection and representative veins removed for histology and immunohistochemistry (smooth muscle antibody staining). A total of 26, mostly bicuspid, valves were identified in 19 of 56 veins (34%) from the external VVP, all orientated to promote blood flow towards the internal VVP. The internal VVP was characterized by four main longitudinal channels with transverse interconnections; the maximum caliber of the longitudinal anterior internal VVP veins was significantly greater than their posterior counterparts (P < 0.001). The luminal architecture of the internal VVP veins was striking, consisting of numerous bridging trabeculae (cords, thin membranes and thick bridges) predominantly within the longitudinal venous channels. Trabeculae were composed of collagen and smooth muscle and also contained numerous small arteries and nerve fibers. A similar internal venous trabecular meshwork is known to exist within the dural venous sinuses of the skull. It may serve to prevent venous overdistension or collapse, to regulate the direction and velocity of venous blood flow, or is possibly involved in thermoregulation or other homeostatic processes. Clin. Anat. 25:609-618, 2012. © 2011 Wiley Periodicals, Inc.

If our IJVs are blocked, many of us rely greatly on our vertebral vein plexuses. Here is more information about the vertebral veins. It's interesting to read about the trabeculae and wonder how the strands and membranes impact upon blood flow. Trabeculae are partially composed of collagen and people with MS have abnormal collagen in their IJVs; do we also have abnormal collagen in our VVs and our trabeculae?
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Re: The vertebral venous plexuses

Postby MarkW » Tue Oct 16, 2012 10:11 am

Hello Cece,
If your IR finds problems in the vertebral veins (most do not investigate them) is it feasible to de-stenose them??
This may mean my (and your?) third session of venoplasty.
Kind regards,
MarkW
Mark Walker - Oxfordshire, England. Registered Pharmacist (UK). 11 years of study around MS.
Mark's CCSVI Report 7-Mar-11:
http://www.telegraph.co.uk/health/8359854/MS-experts-in-Britain-have-to-open-their-minds.html
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Re: The vertebral venous plexuses

Postby 1eye » Tue Oct 16, 2012 11:42 am

A similar internal venous trabecular meshwork is known to exist within the dural venous sinuses of the skull. It may serve to prevent venous overdistension or collapse, to regulate the direction and velocity of venous blood flow, or is possibly involved in thermoregulation or other homeostatic processes.


That's a lot of maybes to a huge question (I had a friend who just died from cancer in her spine).

Let's see, we have

prevention of overdistension or collapse
: maybe.
regulation of velocity and direction of venous blood flow
: maybe.
thermoregulation or other homeostatic processes
: possibly.

This "meshwork" is known to exist inside the veins of the vertebral venous plexus and the dural venous sinuses of the skull.

I am regularly astounded to read about how much we don't know about the mechanisms and functions of the human anatomy. Is it because of our habitual deference to various special medical fields, that we remain in ignorance of these critical structures?

It sounds to me as if the webs, septums, valve differences we have been seeing in CCSVI are possibly part of the body's attempt at implementing more of this "meshwork". Maybe some of it is not abnormal at all!
"Try - Just A Little Bit Harder" - Janis Joplin
CCSVI procedure Albany Aug 2010
'MS' is over - if you want it
Patients sans/without patience
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Re: The vertebral venous plexuses

Postby Cece » Tue Oct 16, 2012 2:18 pm

MarkW wrote:Hello Cece,
If your IR finds problems in the vertebral veins (most do not investigate them) is it feasible to de-stenose them??
This may mean my (and your?) third session of venoplasty.
Kind regards,
MarkW
chronic-cerebrospinal-venous-insufficiency-ccsvi-f40/topic10680-6540.html#p188661

That's a case by Dr. Sclafani in which, yes, he destenosed a vertebral vein after finding stenosis using IVUS. But the circumstances were that an IJV was occluded and not functioning, so the vertebral vein held greater importance. I do not know if he or other IRs would perform such a procedure if both IJVs were functional.

I am currently going with the idea that perfect is the enemy of good: I won't be going for a third venoplasty unless or until I had good reason to. It gives the IRs time to catch up and develop guidelines for the clinical management of CCSVI after the first venoplasty.
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Re: The vertebral venous plexuses

Postby Cece » Tue Oct 16, 2012 2:28 pm

1eye wrote:
A similar internal venous trabecular meshwork is known to exist within the dural venous sinuses of the skull. It may serve to prevent venous overdistension or collapse, to regulate the direction and velocity of venous blood flow, or is possibly involved in thermoregulation or other homeostatic processes.


That's a lot of maybes to a huge question (I had a friend who just died from cancer in her spine).

Let's see, we have

prevention of overdistension or collapse
: maybe.
regulation of velocity and direction of venous blood flow
: maybe.
thermoregulation or other homeostatic processes
: possibly.

This "meshwork" is known to exist inside the veins of the vertebral venous plexus and the dural venous sinuses of the skull.

I am regularly astounded to read about how much we don't know about the mechanisms and functions of the human anatomy. Is it because of our habitual deference to various special medical fields, that we remain in ignorance of these critical structures?

It sounds to me as if the webs, septums, valve differences we have been seeing in CCSVI are possibly part of the body's attempt at implementing more of this "meshwork". Maybe some of it is not abnormal at all!

Couldn't agree more about all the maybes. It's bothered me with all the MS drugs: maybe, maybe, believed to be, unknown mechanism of action.
I don't understand how the trabeculae could function to regulate the velocity and direction of venous blood flow. Maybe there is more information on this to be looked at. Previously we've had the question of why the vertebral veins are able to function when we are upright: why don't they collapse like the jugulars? Trabaculae providing structure might be the answer. If trabeculae prevent overdistension, that may mean that these veins are not able to accomodate excessive flow. Regular veins can distend to higher volumes of flow. Trabeculae could be the reason why vertebral veins are not sufficient to the task when IJVs are blocked and that flow has to go out through another route. Or maybe pwMS are more likely to have more quantatitively and more restrictive trabeculae, compared to normal folks, which would make us more affected by a jugular blockage, and the normal folks more able to compensate by directing blood flow elsewhere including the vertebral veins. This is getting rather speculative on my part. I am just glad when people respond to posts such as this one because it is terribly interesting to me. I was sad not to have access to any images that were part of this article, especially when the "luminal architecture" of the vertebral veins was described as striking.
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Re: The vertebral venous plexuses

Postby Cece » Tue Oct 16, 2012 2:32 pm

1eye wrote:That's a lot of maybes to a huge question (I had a friend who just died from cancer in her spine).

Sympathies on the loss of your friend.
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Re: The vertebral venous plexuses

Postby Cece » Tue Oct 16, 2012 2:38 pm

drsclafani wrote:here you go, cece.

This is my first IVUS of a vertebral vein. The medical necessity for this IVUS was the fact that the internal jugular vein in J3 had long standing occlusion secondary to an overly aggressive angioplasty of a phasic compression of the IJV as it crosses the second vertebra. I saw some abnormality on the prior venogram and wanted to confirm my impression from the venogram that the vertebral had a valve and that it was thickened. I have read that the vertebral vein is valveless, but i think that is incorrect urban legend.

Image

Four images
left: highest level before it turns into a vertebral plexus, which accounts for the tangles at the top of the venogram. this is in the bony canal with vertebral artery and vein nicely visible. on all four images one sees this echogenic dot (yellow arrows). I am thinking this is a web.

left middle: The vertebral artery is no longer seen. The larger common carotid artery is adjacent to this

right middle. Closer to the chest one sees the thickened valve that is immobile (curved orange arrows)

Right The vein is now entering the subclavian vein.

I performed a delicate vertebral vein angioplasty because the left IJV was occluded and not functioning.

This is the case I linked to earlier. I wanted to point out what Dr. Sclafani pointed out with those yellow arrows. This is a vertebral vein and I am guessing that continuous dot seen throughout the length of the vein is an example of trabeculae as discussed here.
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