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Dr. Moguel on restenosis

Posted: Fri Sep 06, 2013 9:47 pm
by Cece
http://ccsvi-ms.ning.com/profiles/blogs ... restenosis
About restenosis after liberation treatment

The liberation treatment, consisting on balloon angioplasty of the three major veins draining the brain (both left jugulars and azygous), is frequently complicated by a new narrowing of the vein in the same segment that was previously dilated.

The restenosis is a usual common phenomenon after any kind of angioplasty on any kind of blood vessels; all vascular specialists are very familiar with it. This complication comes after the injury done in the vessel, followed by an exaggerated response from the body to heal it, creating a hard scar. It is very similar to the scarring that occurs after a surgery, where some patients can develop harder and prominent scars.

The angiographic restenosis is defined by, of course, an angiography that finally reveals that a new narrowing exists. Sometimes the angiography is not enough but a direct measurement can disclose the problem, such as direct pressure register or other image modality like ultrasound, magnetic resonance, computed tomography or optical coherence tomography.

At this time no one is able to know how frequent is the restenosis after a correction of a chronic cerebro-spinal venous insufficiency (CCSVI) because all patients are treated overseas with a lack of follow up by image tests, so there is only a rough estimate by the recurrence of the symptoms which has been called “clinical restenosis” in other well known vascular scenarios.

Multiple sclerosis patients are looking for a repeated vein angioplasty (two, three or more times) but they face the following problems:
Possible hard tissue responsible for the restenosis. This causes a narrowing sometimes impossible to open even at the highest pressure that a balloon can get, leading sometimes to the balloon burst.
Restenosis on restenosis. The treatment of a restenosis has an even higher restenosis risk than the first treatment, creating a vicious circle.
The first problem requires many times the help of a special balloon that is armed with four surgical micro-blades attached to its longitudinal surface (Flextome, Boston Scientific). These micro-blades work while the balloon is fully inflated, as seen in the figure below. Through this endovascular microsurgery, this balloon is able to open the vessel with a minimal lesion and less pressure than is used with a conventional balloon. It is important to note that the more the dilation pressure, the higher the restenosis risk.


The second problem (restenosis after restenosis) is a challenge because of its very high prevalence. It occurs as a result of an exaggerated response from the body, to the damage after the elongation of the tissues during balloon inflation. AT the present time the best tool to reduce this risk is based on the attachment of certain drugs in stents or balloons. These drugs are directed to reduce the cell replication that causes the restenosis.

The actual better way of reducing restenosis without the use of stents are the medicated, also called drug eluting or drug delivering balloons that are capable of deploying the drug in the inner surface of the blood vessel. The actual drug is Paclitaxel, which is part of the treatment of several cancers but the dose in the balloon is very small so it is enough to act locally without any collateral systemic effect. The balloons that we use are Paclitaxel added (Freeway, Eurocor) and it can be consulted on the link http://www.eurocor.de/products/freeway_ ... formation/.
An example taken from a patient with severe restenosis is shown below.

Note in this figure how a severe restenosis is present in a left jugular vein, two years after a successful liberation treatment. The patient had important recovery but a year after she had recurrence of symptoms suggesting a clinical restenosis.

The new narrowing is pointed with the red arrow; a cutting 8x20mm (Flextome) balloon is inflated at low pressure, followed by a medicated 8x20mm balloon (Freeway) inflated at low pressure in the same site.

The vein is finally dilated with a 14x20mm non-compliant conventional balloon (Atlas, Bard products), showing a very good result.

The first attempt to dilate this vein using only the normal balloon was not successful even at a pressure of 20 atmospheres which is the highest that this balloon is capable to afford without bursting.

This case exemplifies the complexity of the treatment for restenosis which is a challenge for every endovascular specialist and the hospital staff as well as the availability of different kinds of therapeutic tools that should include the cutting and the medicated balloons.

Rafael Moguel MD
The Clinics of the Heart
Cozumel, México
originally posted by Dr. Moguel on CCSVI locator

He is saying that restenosis is hard scar tissue. If IRs had advanced virtual histology color flow ivus (which shows the different types of vein wall material based on color, distinguishing between fatty or fibrous or other things), then they could prove or disprove this. It matters because here Dr. Moguel is treating this restenosis with a cutting balloon, which might not be the best choice if the restenosis is due to residual valve material or underdilatation in the first place. Even regular ivus should be able to show the vein expanding under valsalva, which would expand easily if it's residual valve material or underdilatation but not as easily if it is scarring, I think? Not sure on that. Over on CCSVI locator, he includes images of jugulars being angio'ed, which I as always find fascinating. Here the technique is using low pressure medicated balloons and cutting balloons but not high pressure balloons. The vein opens up as seen in the images. It looks like a good result but follow-up would be informative.

edited: Looking again at his final result image, I think I see extravasation in the area of the valve (two small trails of blood flow leaking outside of the vein) which could be a result of the cutting balloon and a contributor to clotting. The vein definitely went from closed to open, and I hope it stayed open.