drsclafani wrote:Any questions?
When you say that 82% had bilateral angioplasty, was that 82% of 150 patients or 82% of the 93% who had angioplasty of the IJVs? It's a high percentage for bilateral IJV stenoses.
I like the statement that CCSVI stenoses are different than stenoses caused by thrombosis, recanalization, scarring, tumor encasement and access intimal hyperplasia. Defining what CCSVI is not is as important as defining what CCSVI is.
We sought to determine the balloon sizes and pressures that were necessary to attain complete distension of IJV obstructions due to CCSVI.
I think we can agree that complete distension of such obstructions is a worthy goal if it is correct that recoil is likely if an obstruction is incompletely distended, and if complete distension can be safely achieved.
Angioplasty was based upon venographic findings such as stenosis >50%, stasis, reflux, collaterals or upon intravascular ultrasound (IVUS) findings, such as cross sectional area stenoses (CSA)>50%, immobile valves, septum, membranes or webs.
Why was >50% used as the percentage? I seem to remember conversations here about a blockage in a vein having a greater effect on flow than a blockage in an artery, and therefore lower percentages such as 30% or 40% might require treatment?
You mention septums, I am curious: the Cleveland Clinic autopsy study found a significant number of septums in the IJVS of MS patients. I would've expected fewer septums since we don't hear much about them. In what percentage of your patients have you found septums in the IJVs? Can a septum be clearly distinguished from a valve, or from a membrane or web, on IVUS? How have septums been responding to treatment? Any ideas of how to improve treatment of septums?
It is interesting too that this breaks down what can be seen on venography: stenosis>50%, stasis, reflux or collaterals. (I remember you showing me the stasis in my left jugular, when I was there in July.) This is compared to what can be seen on IVUS: stenoses>50% as measured by cross sectional area, immobile valves, septum, membranes or webs. Stasis and reflux and collaterals are not listed as being seen on IVUS? But CSA and the intraluminal abnormalities (valves, septums, membranes, webs) are not listed as being seen on venography. Ok, no question there, just working through the differences between the IVUS and venography.
lnflation endpoints were elimination of balloon waist without recoil or exceeding rated burst pressure.
If these are Atlas balloons, the burst pressure is quite high, around 30 atm? Then burst pressure isn't a factor, since your highest pressure was 24 atm, and you went up in pressure until the waist was eliminated without recoil. I don't think we've had any other abstracts showing the use of high pressure balloons in CCSVI. If a high pressure balloon were to damage the vein wall, this would not be immediately known, but would show up over a few weeks or months, correct? I would like for this abstract to be demonstrative of safety of high pressure balloons, because I've heard both sides of the discussion on high pressure balloons, but if any damage isn't immediate, then this does not serve that purpose.
What is the difference between a dissection and a perforation?
All but one dissection and one thrombosis occurred prior to using IVUS CSA for balloon selection. Complication rate of 16% using visual estimation was reduced to 1.3% using IVUS CSA measurements.
A strong statement here. Complications reduced from 16% to 1.3%, with the use of IVUS! Have you shared this with other IRs? What has the response been? Is this influencing other IRs to use IVUS, and if not, what would it take to influence IRs into using IVUS in CCSVI? As a patient advocate, I would like to see the safest, best methods adopted. There is no reason to take a 16% risk of damage of thrombosis or dissection of these precious veins, if the risk could be 1%.
Conclusion :
1. Hlgh pressures are requlred to completely dilate the lesions of CCSVI.
The alternative to high pressure is to go up in balloon size or to accept an endpoint with residual waisting or recoil. In this abstract, you did not explore the alternative of going up in balloon size, which you really can't do, if you belive that will lead to thrombosis or damage (by a combination of oversizing balloons and high pressure). I am not sure that the abstract supports the conclusion that high pressure is required. Nor do we know if complete dilation is superior to incomplete dilation, in terms of long-term results and safety, although it seems logical.
