DrSclafani answers some questions

[Rosegirl]

Dr. S,

Could you explain the difference between a stenosis and a thrombosis? Is it harder to treat one than the other? Is one more life-threatening than the other? And how are they diagnosed and treated, especially if they appear after a venogram?

Gratefully, Rosegirl

[drsclafani]

Dr. S,

Could you explain the difference between a stenosis and a thrombosis? Is it harder to treat one than the other? Is one more life-threatening than the other? And how are they diagnosed and treated, especially if they appear after a venogram?

Gratefully, Rosegirl

a stenosis is a narrowed blood vessel resulting from diseases such as tumor, arteriosclerosis, fibrosis, congenital problems.

a thrombosis is blood clot filling the blood vessel. either one is potentially life threatening, depedneing upon the circumstances and the vessel that involve.

stenoses can be diagnosed by ultrasound, arteriography, venography and possibly by mrv or mra and ctv or cta

Thrombosis can be diagnosed using ultrasound, angiography, ct or mr

[drsclafani]

Dr. S., how convinced are you that CCSVI is congenital? One recent study suggests it is caused by chronic MS and not present at all in most early MS cases.

http://www.ncbi.nlm.nih.gov/pubmed/21041329

I read that paper with interest. It is a very interesting paper that warrants study and analysis.

The authors performed venography on 42 patients looking for stenoses. They had two groups, an early group and a late MS group. The early group was comprised of 18 RRMS of less than five years of duration and 11 patients with clinically isolated syndrome. The late group was comprised of patient with RRMS of more than te3n years duration. SPMS and PPMS were excluded.

The authors required that three criteria be met:
1. stenosis were greater than 50%. the authors did not document whether this was cross-sectional area or diameter measurements.
2. delayed clearance of the contrast media
3. absence of valve leaflets.
Collateral veins were not considered.

They found that 19 of 42 patients had a vascular stenosis. Most had only one vein stenotic. Not surprisingly only one of 11 patients with CIS had a stenosis. Moreover, stenosis was more prevalent in the group that had MS greater than ten years.

So while almost 50% of their patients had stenosis, the stenosis only involved one vessel in most of these patients.

The authors concluded that because early MS was not associated with as much stenosis as lfor patients who had had the MS for ten years or more, this was not likely to be a congenital problem but one that was acquired.

I was surprised by this information. i do not have sufficient patients in each group to make such an analysis at this point. So i cannot corrorboarate or refute their assessments.

I thought there were several deficiencies of the study
1. they only used 50 cc of contrast for all these angiograms. This seems liike much less than i would have expected. They did at least 8 injections, meaning that each angiogram would only have six cc of contrast media. That is not very much contrast
2. i do not know why they required three criteria to be met to have a stenosis
3. they do not mention whether they calculate the stenosis as a percentage of diameter reduction or cross sectional area reduction. This is very important 4. they excluded valve prominence as a finding of stenosis. I believe this is a valve disease, so this is at cross currents with my observations. I have done several manuevers that document that these prominent valves do not open properly. For example IVUS is quite clear. Also dilatation of these areas shows a pronounced "waist" on the balloon at the oint of obstruction.
5. i thought that some of the cases that they showed not having stenoses actually had stenoses.

So, i consider the paper food for thought, but that it could not make such conclusions. I am concerned about how these patients were evaluated.

nonetheless, while it is certainly not a strong endorsement, this paper does show association between MS and venous stenosis.

I think we need to keep in mind, that we are not treating MS, we are treating CCSVI and our goals are improvement in quality of life.

[Cece]

3. they do not mention whether they calculate the stenosis as a percentage of diameter reduction or cross sectional area reduction. This is very important

If it's diameter reduction, that sets the bar higher, doesn't it?

[NHE]

Hi Cece,

3. they do not mention whether they calculate the stenosis as a percentage of diameter reduction or cross sectional area reduction. This is very important

If it's diameter reduction, that sets the bar higher, doesn't it?

My understanding is that the veins are morphologically dynamic and are not perfect circles. If, for example, the vein was ellipsoid or oval in shape, which diameter would you choose? The long one or the short one? Such a choice would affect the outcome of a study. In constrast, the results of a cross sectional area measurement would be less dependent on the shape of the vein.

NHE

[drsclafani]

Hi Cece,

3. they do not mention whether they calculate the stenosis as a percentage of diameter reduction or cross sectional area reduction. This is very important

If it's diameter reduction, that sets the bar higher, doesn't it?

My understanding is that the veins are morphologically dynamic and are not perfect circles. If, for example, the vein was ellipsoid or oval in shape, which diameter would you choose? The long one or the short one? Such a choice would affect the outcome of a study. In constrast, the results of a cross sectional area measurement would be less dependent on the shape of the vein.

NHE

crosss sectional area is more relevant than diameter. CSA measurements also result in higher percentages of stenosis because the measure is the square of the radius as opposed to the diameter.
In addition, NHE correctly stated that the jugular vein is constantly changing in its dimensions. During end-inspiration flow is not as great as during end-expiration: so the normal vein does not distend as much as during end-expiration. Thus comparing fixed stenosis area or diameter to a more cephalad dynamic jugular vein will result in a lower % stensosis during end inspiration than during endexpiration.

whew!

On the whole, an interesting paper. it surely confirms that stenosis occurs in MS. Techniques and arbitrary definitions and inclusion and exclussion criteria limit the conclusions but seemed fairly unbiased.

Lets hope that some of the investigators start looking at ccsvi as its own entity rather than chasing the horse and the cart

[drsclafani]

3. they do not mention whether they calculate the stenosis as a percentage of diameter reduction or cross sectional area reduction. This is very important

If it's diameter reduction, that sets the bar higher, doesn't it?[/quote

see prior post
yes it does, cece the mathematician!

[phe]

How would one treat a pt with angioplasty (venous or otherwise) who can't lie flat on their back. My MRI was ruined the other day by a leg that pulled up and relaxed constantly for 40 min in the tube despite ativan and clomazapan. Its a positional reaction to a shortened psoas muscle and spasticity I think...I apparently don't have a lumbar spine nor pelvis that lie flat anymre. Wheelchairs are great except for the damage caused by not standing over time. BTW my MS is spinal only...thnx...from Canadian MS'er

[Cece]

http://www.gogeometry.com/problem/p190_ ... circle.gif

To visualize, here are two circles, the second has a 50% reduction in diameter from the first but its area has shrunken considerably more.

With it being dynamic, that does not make it any easier!

[Nunzio]

http://www.gogeometry.com/problem/p190_ ... circle.gif

To visualize, here are two circles, the second has a 50% reduction in diameter from the first but its area has shrunken considerably more.

With it being dynamic, that does not make it any easier!

Since the diameter is directly proportional to the radius; i.e. if the diameter is reduced 50% then the radius is also 50% and since the area is proportional to the radius squared than is obvious that if you cut the diameter 50% the resulting area will be 25% of the original area.

[cmozena]

The sampling size of these studies are not statistically significant yet the conclusions, however, are made on a grand scale!

Why have we not drilled down on the Neurology study involving nearly 9,000 MS patients.
[/url]http://www.ncbi.nlm.nih.gov/pubmed/20350978

Does anyone know what their criteria for 'vascular commorbidity' was?

[Sotiris]

...Does anyone know what their criteria for 'vascular commorbidity' was?

From the paper:

For analysis, we created a category for vascular comorbidity, including diabetes, hypertension, heart disease, hypercholesterolemia, and peripheral vascular disease.

[Cece]

The sampling size of these studies are not statistically significant yet the conclusions, however, are made on a grand scale!

Why have we not drilled down on the Neurology study involving nearly 9,000 MS patients.
[/url]http://www.ncbi.nlm.nih.gov/pubmed/20350978

Does anyone know what their criteria for 'vascular commorbidity' was?

Yes, cheerleader took care of that one for us, it wasn't as relevant to CCSVI as it sounded:

http://www.thisisms.com/ftopicp-111488.html#111488

[drsclafani]

How would one treat a pt with angioplasty (venous or otherwise) who can't lie flat on their back. My MRI was ruined the other day by a leg that pulled up and relaxed constantly for 40 min in the tube despite ativan and clomazapan. Its a positional reaction to a shortened psoas muscle and spasticity I think...I apparently don't have a lumbar spine nor pelvis that lie flat anymre. Wheelchairs are great except for the damage caused by not standing over time. BTW my MS is spinal only...thnx...from Canadian MS'er

i am so sorry for your dilemna

Firstly, i would perform ultrasound to evaluate for ccsvi. if positive i would do venography under sedation. if this is not successful, and it probably isnt, i would treat under general anesthesia. if the contract was fixed, even under general anesthesia, I would approach the vein from the left jugular vein from as high up the neck as possible.
After treatment of the left side I would try to cross from the left jugular vein via the left then the right inominate veins into the right jugular vein. and perform treatment of any stenoses on the right side.

Then I would go from the left neck puncture downstream into the azygos vein and continue treatment.

This would be the first time I have done it, but these techniques have been done by others for many reasons.

[David1949]

Dr. Sclafani, to your knowledge is anyone doing dissections of corpses of people with MS to see if vein abnormalities are present? It would be especially interesting to know if valve abnormalities and webs are found in the azygous vein at the same rate mentioned by Dr. Sinan.

BTW is there way that we can donate our bodies for CCSVI research? (post-mortem of course.)