IVUS

DrCumming · Post by **DrCumming** » Fri May 06, 2011 3:48 am

Hi all,

As you know Dr Scalafini and I (thanks to his suggestion) are very interested and keen about the use of IVUS for performing CCSVI procedures. The additional information that IVUS provides is invaluable (in my opinion). It has allowed us to have a better understanding of the cause of obstructions, better sizing of balloons, better evaluation post ballooning and identification of stenosis not seen on venography.

I'll start with great example of the azygous.

Case 1: Azygous

Here is the venogram

http://youtu.be/O2_8a7Yo2VE?hd=1

No stenosis or obstruction seen.

Next is the IVUS at the level of the valves

http://youtu.be/Pe3PBDxAvcc

Wish there was a way to embed the video in the post.

The azygous vein stenosis was not visible on venography (despite multiple views).

I'll post static images later with more details.

Cece · Post by **Cece** » Fri May 06, 2011 7:49 am

Looking forward to the static images too. You have to be fast to see the venogram movie. I can see the valve issue in the IVUS. Thanks for posting these. I can't imagine IVUS software being low priority to the IT guys, it is clearly top priority!!

DrCumming · Post by **DrCumming** » Fri May 06, 2011 9:59 am

Here are the static images.

First is IVUS at the level of the valves. Here we are looking at the size and area of the valve at maximal opening. Not shown is the size of the azygous at this level but it measures 16x14mm

Next is the azygous vein just past (distal) to the valves.

So, first question, is what is the percent stenosis? Do we use the area or one of the diameter measurements? What do we use as denominator? At the level of valves we know the vein dilates. This is normal. I do not think this is the right spot to use as it will artificially make the stenosis worse then it is. What about using the normal appearing azygous just past the valves? Or should it be the segment of azygous before (proximal) to the valves?

Cece · Post by **Cece** » Fri May 06, 2011 5:01 pm

based on what drsclafani said in this post
( http://www.thisisms.com/ftopicp-162730.html#162730 )
I think the area measurement is more informative than the diameters.

I agree that if it is dilated at the area of the valves then that is not the spot to use.

What do you do? Do you have the cross sectional areas calculated for your balloons? Would you guess that proximal is better? Either distal or proximal measurements might be affected by the hemodynamic impact of the valve.

I am reminded of my 100% blockage in my left jugular, there would have been no way to measure it distal to the blockage, there was no flow there.

drsclafani · Post by **drsclafani** » Fri May 06, 2011 7:31 pm

Cece wrote:based on what drsclafani said in this post
( http://www.thisisms.com/ftopicp-162730.html#162730 )
I think the area measurement is more informative than the diameters.

I agree that if it is dilated at the area of the valves then that is not the spot to use.

What do you do? Do you have the cross sectional areas calculated for your balloons? Would you guess that proximal is better? Either distal or proximal measurements might be affected by the hemodynamic impact of the valve.

I am reminded of my 100% blockage in my left jugular, there would have been no way to measure it distal to the blockage, there was no flow there.

you do not need to have flow in oorder to measure the cross sectional area of the vein. even when the valves are stenosed, the outer diameter of the vein is obvious.

DrCumming · Post by **DrCumming** » Sat May 07, 2011 3:54 am

Sal is correct - that is one of the many great things about IVUS

continuing with the above case...

A static image from the venogram - no stenosis

IVUS at valves

and IVUS just before the valves

Area before the valves is 106 mm2 and at the valves is 67 mm2. I do not know which diameter you would use to calculate a traditional percent stenosis.

And most importantly, is this a significant stenosis? Does the fact that there are no collaterals draining the azygous vein mean the stenosis is not significant?

We chose to dilate. And CeCe we picked a 12 mm balloon which has a cross sectional area of 113 mm2 (to match the distal segment of the azygous).

Here is post ballooning with 12 mm

Little better, area now measure 77 mm2. Are we done?

Decided to continue with a 14 mm balloon and here is the IVUS after

Better again, area now 85 mm2. But the upper leaflet is still not opening completely. Is this result good enough?

I decided to stop there. But I do not know if that is the right answer.

One of the top ten rules of IR is the enemy of good is perfect.

Cece · Post by **Cece** » Sat May 07, 2011 9:06 am

And most importantly, is this a significant stenosis? Does the fact that there are no collaterals draining the azygous vein mean the stenosis is not significant?

Was there reflux evident?
Did the patient have spinal involvement in their MS? (Assuming an unproven connection between azygous stenoses and spinal lesions.)

MegansMom · Post by **MegansMom** » Sat May 07, 2011 9:35 am

I think IVUS adds much to the thoroughness in many cases. Some IRs may say it's not needed. I have listed some obvious pros and cons can one of you IRs comment?

IVUS ( intravenous ultrasound )

Cons:
Expensive piece of equipment
Physicians have to learn how to use the equipment and master using it
Takes much longer in many cases - 1 hr case may take 3 hrs.
Adds costs to procedure

Pros:
Very thorough, finds things venograms miss
Helps size balloons and assess anomalies
Less fluoroscopy time and maybe less contrast?
Improves the outcome- less defects missed

DrCumming · Post by **DrCumming** » Sat May 07, 2011 12:09 pm

MegansMom wrote:I think IVUS adds much to the thoroughness in many cases. Some IRs may say it's not needed. I have listed some obvious pros and cons can one of you IRs comment?

IVUS ( intravenous ultrasound )

Cons:
Expensive piece of equipment
Physicians have to learn how to use the equipment and master using it
Takes much longer in many cases - 1 hr case may take 3 hrs.
Adds costs to procedure

Pros:
Very thorough, finds things venograms miss
Helps size balloons and assess anomalies
Less fluoroscopy time and maybe less contrast?
Improves the outcome- less defects missed

Hi Cat,

That's a pretty good summary.

Cons: I have some ideas to try and speed up procedure times with IVUS - will see how they work out. Cost is cost. If outcomes are better then its worth it.

Pros: Definitely see stenosis not seen on venogram. Better sizing and assessment of venoplasty, with less intimal damage. Does this improve patency/durability - I do not know.

Sal may have a few other pearls to add.

WeWillBeatMS · Post by **WeWillBeatMS** » Tue May 10, 2011 10:41 am

DrCumming,

Are you using IVUS on all patients you treat for CCSVI? If not, what percentage of patients do you end up using it for? and what is the determining factor to use it instead of just the venogram?

Thanks,

WeWillBeatMS

DrCumming · Post by **DrCumming** » Tue May 10, 2011 1:10 pm

WeWillBeatMS wrote:DrCumming,

Are you using IVUS on all patients you treat for CCSVI? If not, what percentage of patients do you end up using it for? and what is the determining factor to use it instead of just the venogram?

Thanks,

WeWillBeatMS

Rightly or wrongly, I am now using it on everyone. We all are in a learning phase and I believe it adds significant value that can help in better decision making.

Brainteaser · Post by **Brainteaser** » Tue May 10, 2011 3:00 pm

Apart from Drs Cumming and Sclafani, who uses IVUS?

Do Vascular Surgeons use it or just IRs? Zamboni and Ludyga are VSs and I'm not sure they use it.

Does anyone have good results without using IVUS?

Does anyone using it, not have good results?

Cece · Post by **Cece** » Tue May 10, 2011 3:21 pm

www.thisisms.com/ftopicp-162048.html#162048
www.thisisms.com/ftopicp-162054.html#162054

While I said that Dr. Sclafani's use of IVUS to measure stenoses was unique to him, that is no longer true, as Dr. Cumming uses it this way also.

Dr. Dake and Dr. Haskal have used IVUS for CCSVI but are not treating outside of trials, as far as I know.

Dr. Arata has used it at the hospital in MT cases but does not have it at his clinic.

I have not heard anyone else mention their IR using IVUS.

IVUS have historically been more commonly used by cardiologists, not IRs.

I don't think the questions about results can really be answered yet. Too soon....

I love talking about IVUS.

jamit · Post by **jamit** » Tue May 10, 2011 8:05 pm

In a hospital setting I gather most IRs use it at least all the ones I have talked to and that is quite a few. I think it is not so much who uses it as it is how they they use it and how experienced they are using it in veins an interpreting what they see correctly and acting on what they see. I remember a Sclafani post where he talks about a learning curve there as well. Also some might be using it but if they are trying to fit too many patients into too little time I should think it quickly loses value.

In short I think it is not just who uses it that is important.

drsclafani · Post by **drsclafani** » Wed May 11, 2011 8:16 am

MegansMom wrote:I think IVUS adds much to the thoroughness in many cases. Some IRs may say it's not needed. I have listed some obvious pros and cons can one of you IRs comment?

IVUS ( intravenous ultrasound )

Cons:
Expensive piece of equipment

YES. basic unit is about $100,000. If you amortize the cost over three years and treat 300 patients per year, cost is about $150 per patient. for unit. plus about $700 per catheter probe.

Physicians have to learn how to use the equipment and master using it

TRUE but it is a good teacher of what to look at.

Takes much longer in many cases - 1 hr case may take 3 hrs.

NOT ACCURATE, DOES NOT TRIPLE TIME.with experience it adds about 30 -60 minutes to a procedure. some of the additional time results from post angioplasty IVUS showing that initial angioplasty was not adequate. dds costs to procedure

Pros:
Very thorough, finds things venograms miss

DEFINITELY TRUE

Helps size balloons and assess anomalies

ABSOLUTELY TRUE

Less fluoroscopy time and maybe less contrast?

UNTRUE. May increase contrast and fluoroscopy time because it reveals unsatisfactory results from angioplasty that require additional fluoro and contrast tocomplete

Improves the outcome- less defects missed

TRUE....BUT ALREADY STATED.

OTHER ADVANTAGES
1. MORE EASILY EVALUATES THE DURAL SINUSES WHEN CATHETER CANNOT ADVANCE ACROSS SKULL BASE
2. PRECISES LOCATION OF STENOSIS
3. DETECTS SUBTLE INTRALUMINAL WEBS AND SEPTAE
4. CAN GO MORE DISTAL TO A DIAGNOSTIC CATHETER