0:00

Hi everybody and thank you for attending tonight's cardiac

0:04

CT lecture with Dr.

0:06

Fontes. Just a reminder, um, if you have any questions,

0:09

feel free to type them in the chat and we'll call on you.

0:13

You can ask Dr. Fontes directly, uh,

0:15

or you can also use the hand raising hand emoji.

0:19

Um, and we will call on you too. So Dr.

0:22

Fni, whenever you're ready.

0:24

Okay, so we're gonna kind of go over a couple of things

0:27

with this lecture.

0:29

We're gonna go over the basics of how

0:30

to perform a TAVR CT depending on

0:32

type of scanner you have available.

0:34

Then we're gonna gonna move through the, through the process

0:37

of actual evaluating the aortic root

0:40

and the anatomical definitions that you need to know

0:43

for a TAVR assessment.

0:45

And I'm gonna briefly go through vascular access,

0:47

important points to remember, and then what to do

0:49

and how do we use cardiac CT in patients who have had tavr.

0:53

And more importantly, a brief overview of how do we do valve

0:55

and valve implantation.

0:56

So, got a lot to cover, uh, because of our time constraint

1:00

and the amount of information that we have to have.

1:03

This is just kind of one of those question concepts

1:05

that we kind of wanna go over in particularly

1:08

and instead of asking you

1:09

to answer a question, pick a choice.

1:10

Really, there's a couple of things

1:12

to remember why cardiac CT is a standard for sizing of this

1:17

and it really comes with the biggest thing for the patient.

1:20

And Corona Cardiac cardiac CT is really much associated

1:23

with the lower risk of annual injury rupture

1:25

because its ability to maintain that spatial resolution

1:28

so thin in a three dimensional approach.

1:30

So what are the factors in patient things

1:32

to remember about type doing tavr?

1:37

First of all, there's the acquisition mode

1:40

and your cranial cordal coverage.

1:42

You have two options. You can get a prospectively gated high

1:45

pitch scan.

1:46

Usually that requires dual source scanners,

1:49

so obviously susceptible to step artifacts

1:51

with heart rate variability or an abnormal rhythm.

1:54

There's obviously the most commonly used,

1:56

the retrospectively gated low pitch helical scanning,

1:58

which most scanners including dual source scanners can do

2:01

and it allows for coverage of an entire cardiac cycle

2:04

with EKG editing.

2:05

For data salvage, meaning there may be some motion artifact,

2:08

but 'cause of the overlap of the nature

2:09

of the retrospective helical scan, you may be able to

2:13

to salvage some of those data points.

2:16

And then of course with now some

2:17

of the modern wire detector row scanners

2:19

of volumetric scanners,

2:21

you can do a single beat acquisition.

2:22

It can be both perspective or retrospectively gated,

2:24

but allows for reduction in any star step artifacts as well

2:27

as a visceral ization of everything in patients

2:30

who have significant arrhythmias.

2:33

So depending on the type of scanner that you have,

2:35

these are the kind of recommended modes of acquisitions

2:37

for the cardiac dataset, meaning you're gonna have the task

2:40

of doing a cardiac function assessment of the heart

2:43

and the aortic root, particularly when

2:45

capturing systolic phases.

2:47

But you also have the task of looking at the aorta,

2:49

both at the chest, the abdomen, as part of the upper pelvis

2:52

for for scan acquisition.

2:53

So this is kind of how we're gonna focus on the

2:55

cardiac dataset per cell.

2:57

If you have an older 64 row scanner, obviously the spiral

3:02

acquisition of the scan in a retrospective

3:06

image is the modality of choice, both of theo resolution

3:09

as well as uh, you know, artifact minimization.

3:14

As far as the other scanner to do, if you have a revolution,

3:17

which is some of the newer GE scanners as are,

3:20

that can be done with simply a prospectively kg gated single

3:24

one being acquisition.

3:25

Same with Phillips scanners and Siemens scanners.

3:27

Most of these require helo acquisition

3:29

with retrospectively gated EKG construction,

3:31

whereas the Toshiba cooling one, it comes

3:33

with both the 64 24 row scanners,

3:35

whereas you can see if you don't have a volumetric wind

3:38

detector world scanner, most

3:39

of the times you're gonna be doing it for uh,

3:42

retrospectively helical.

3:43

When it comes to the contrast administration,

3:45

you're gonna need a dual injector system

3:46

that has both contrast and saline

3:48

and the injection rates can vary,

3:50

but usually we're talking rates

3:51

of four five milliliters per second.

3:52

For most patients, the iodine concentration

3:55

and the contrast type remains standard due,

3:58

but of contrast is gonna dependent be dependent on both the

4:03

patient and scanner factors.

4:07

So what's going to impact your imaging quality?

4:10

Obviously the body optimize both the voltage as well

4:12

as the current cardio can also affect your cxi coverage,

4:16

particularly when the apex

4:17

of the ventricle is more displaced inferiorly.

4:20

The heart rate and rhythm, really this is a

4:23

strongly challenging case.

4:24

While heart fast heart rates are not a challenge

4:26

for retrospective CUIC scanning your regular rhythms

4:30

can be quite challenging.

4:31

In fact, they can almost be, uh, prohibitive

4:34

of a diagnostic imaging modality.

4:36

So it's important to be aware of those

4:38

and more importantly, how frequently those

4:40

rhythms are co coming.

4:41

Last but not least, renal function adjustments can be needed

4:44

to the protocol, but unfortunately the patient population

4:46

has pretty advanced chronic kidney disease.

4:47

And then of course, the intravenous access

4:49

to match contrast flow rates that you need.

4:52

So most of the TAVR protocols

4:54

com compo are composed of two segments.

4:56

You have an EKG synchronized cardiac CT dataset,

4:59

and also a non eek g synchronized CT angiogram

5:02

of the upper thoracic vasculature going

5:04

above the clavicles all the way down to the

5:07

immoral vasculature.

5:09

You have two really options to do this.

5:10

You can do a dedicated EKG gated of the heart, followed

5:13

by a non gated CT of the thax andin pelvis,

5:16

or you can do an entirely gated CT GA E KG

5:22

G scan of the thax, followed by non-G gated tissue doses.

5:26

And the amount of heart rate variability

5:28

are gonna be important for dose.

5:30

Now for this particular cases,

5:32

heart rate control medications really not recommended in

5:34

severe aortic stenosis,

5:36

so don't be too concerned about

5:37

keeping those heart rates down.

5:38

And more importantly, giving patients really high doses

5:41

of beta blockers.

5:42

The one thing that is definitely contraindicated is this

5:45

administration of nitrates.

5:47

As you can imagine, significant

5:48

of dilatation can potentiate the gradient

5:52

or the pressure difference in, uh,

5:54

stenotic valve giving patient potential fatal hypotension.

5:58

Obviously, when it comes to the CT angiogram of the abdomen

6:01

and pcor TAVRs, you wanna ensure

6:02

that in this particular case, it's different from what most

6:05

of the CT angiograms

6:06

that you're probably doing in routine clinical evaluation

6:08

For standard aorta

6:14

evaluations, in this ones we want 10 slice collations

6:16

with slice thickness, ideally less than one

6:18

and a half millimeters in thickness.

6:20

The contrast volume also has to account

6:22

for the brief intermission needing to reposition the table

6:24

and adjust scan settings.

6:26

So you have to take into account those extra four to three,

6:28

three to four seconds of delay, as well

6:30

as the entire duration of the four second scan

6:32

that will follow that, that transition.

6:35

So when it comes to your recommended contrast

6:37

administration, like I said, the volume can vary.

6:39

It can be as low as 30 milliliters.

6:41

I know that sounds impossible, but it can be done.

6:43

But again, the volume usually does the 100

6:45

hundred 20 milliliters.

6:47

As far as timing, and this is a very, very important thing

6:49

to remember, your volume is tracking.

6:51

If that's what you are doing, has to be in the region

6:53

of interest in the ascending aorta or the thoracic aorta.

6:56

Usually I recommend a hundred house full unit base

6:58

above baseline, or you can do it at 180 house full units

7:01

depending on the scanner that you have.

7:03

Now, when it comes to damage reconstructions

7:05

for these scans, you wanna ensure

7:06

that you reconstruct the smallest available ation

7:08

depending on your scanner.

7:09

Usually it's either half a millimeter slides

7:11

or most scanners

7:12

with a2 five millimeter scan reconstruction.

7:15

The iterative reconstruction of whatever type of scanner

7:18

that you use has to be a standard soft tissue kernel

7:20

with a moderate overlap to ensure

7:22

that you have soft imaging, uh, non-significant, uh,

7:25

you know, sharp kernel reconstruction in order to be able

7:29

to see the sharp delineation of the, uh, annulus.

7:32

Last but not least, and this is extremely important,

7:34

you have to ensure that you have 5% increments

7:37

for evaluation of the entire cardiac cycle.

7:39

This can be a zero to 95%

7:41

or zero to a hundred percent at 5% increments.

7:45

If you don't wanna use uh, percentages

7:47

and you wanna use milliseconds, that's also allowed.

7:49

Usually alternative is 50 millisecond increments,

7:52

but you have to ensure that if you're going

7:54

to do a functional assessment, you have 20 separate phases

7:56

of the cardiac cycle to ensure that you've been standard

7:59

for evaluation for cardiac function,

8:01

in particularly for the valve.

8:02

The field of view may also vary,

8:04

but just usually prefer to be anywhere between 200

8:06

and 250 millimeters for the cardiac portion.

8:09

And of course, the matrix needs to be in the 512 by 512

8:14

to maximize spatial resolution.

8:16

As far as the EKG editing, you have to use it

8:19

to minimize any artifacts

8:20

that may be seen in heart rate variability.

8:22

So now what we're going to do is we're going

8:24

to really look at CT planning

8:26

and tavern, really looking at the valve sizing.

8:28

This is really the most challenging part.

8:31

What you want to be doing in this is delineate the root

8:35

geometry, precise internal measure

8:37

of the anatomical relations within the outflow tract,

8:40

the aortic cannulas, the root, and the coronary osteo.

8:43

So, so how do we do that?

8:45

The most important part of this evaluation is the

8:48

aortic annulus.

8:49

And this is a anatomical, um,

8:56

a non anatomical existing part of the heart,

8:59

but it's something that requires you to ensure

9:01

that you have it perfectly aligned.

9:06

The luminal contour can be done with a virtual plane aligned

9:09

to the most basal attachment points.

9:11

So these are the colors square that you see

9:13

for the three aortic valve cusps

9:16

or what we call the basal hinge points.

9:18

As you can see on the three dimensional image, as well

9:20

as the two dimensional image.

9:21

You want to be sure where that, uh, you know, turn

9:25

or that basal hinge point of the valve leaflets located is

9:28

where you're going to align each one

9:30

of your of your hinge points.

9:31

This has, this can be done two ways.

9:34

You can do it manually using a standard multiplanar

9:36

reformatting or you can use

9:38

what I recommend if you're starting out

9:39

with this software-based assistance,

9:41

where the program allows you to do a manual selection

9:44

of the hinge points for each individual leaflet while

9:46

automatically adjusting the plane without you needing

9:50

to manipulate the, the plan or reforms.

9:52

Or you can always rely on the software automated

9:54

but verify what the software's using.

9:56

I think with artificial intelligence, some

9:58

of the softwares are getting a little better at it,

10:00

but they still require, I find that for most beginners,

10:03

ends up being that software based assistance

10:05

where you select the hinge points and adjusted accordingly.

10:09

The most important thing when it comes

10:10

to actually measuring your annulus,

10:12

and this is really important for the type

10:13

of software they're using, you really want

10:16

to avoid using a free hand tool

10:18

or a household based counter detection

10:20

'cause you're going to often lead

10:22

or result in ir regular lines of measurements

10:25

that are really not going to be smoothened, which is

10:28

where you can have a lot of issues

10:30

with the precision of the measurement.

10:32

You can try polygonal segmentation points connected

10:35

by the straight line without any interpolation,

10:38

but again, these are not necessarily preferred methods

10:40

because they can lead to some overestimation issues.

10:42

What the SCCT

10:43

and the A CR recommend are manually placed segmentation

10:48

points with a connected cubic line

10:50

or a elastic ruler type of approach that allows you

10:53

to smoothen the borders in order to get that right.

10:56

A lot of this leads to a more consistent

10:58

and accurate ification of the annual perimeter when compared

11:03

to some of the polygonal and the freehand tools.

11:06

As you can see on the examples provided on the images.

11:09

When it comes to the aortic cannulas though,

11:11

it's always measured in Sicily, usually anywhere

11:14

between the 25 to 40% phase of the cardiac cycle

11:18

or between 200

11:20

and 400 milliseconds of your using milliseconds approach.

11:23

This is measured in Sicily with the face

11:26

yielding the largest dimension,

11:28

but it also has to have the images

11:30

with the sharpest annular contour without blurring,

11:33

or heaven forbid you have double contour artifacts.

11:36

Make sure that there's adequate contrast continuation

11:38

to be able to delineate the annulus first as well as

11:42

to ensure that you have pretty much a well aligned motion

11:47

free assessment of that annulus.

11:50

So that's the important part when you look at your annulus

11:53

size and when you kind of measure those things.

11:55

The next step in your evaluation,

11:56

and remember we gave you a template to kind of follow along,

12:00

is going to be looking at the aortic annulus anatomy itself

12:03

with the degree of calcification involved.

12:05

There are different types of categorization

12:07

of calcium in the outflow track

12:09

and depending on the location of the calcium as well

12:12

as the extent is gonna kind of determine how you grade it,

12:15

we define mild calcification of the landing zone

12:19

or the annulus as a single, a adherent,

12:21

non protruding focus of calcium.

12:23

So if you don't see a protruding into your outflow tract,

12:26

it's very mild.

12:28

When you see two or more nodules

12:31

or a nodule that has limited perion into the annular

12:34

or heaven forbids of annular lumen, then

12:35

that's considered moderate and then severe obviously can be

12:38

single or multiple nodules of cancer

12:40

that protruding both the annular lumen

12:42

and then extend not just in the annulus,

12:44

but into the left ventricular outflow tract, which is one

12:47

of the things that you, you definitely wanna avoid.

12:50

Now when it comes to the calcifications, uh,

12:53

the calcium volume increase is obviously something

12:57

that we care about, particularly the upper left ventricular

13:00

outflow tract because in this particular type

13:03

of calcification,

13:04

particularly if it's on the non coronary cast, tends

13:07

to be the most predictable having aortic root injury.

13:10

So in your reports, you wanna make sure you take the time

13:13

to look or the presence, the amount of calcification

13:17

of outflow tract, uh, calcium

13:19

and more importantly where it relates to the coronary cast.

13:21

If it's on the left, if it's in the right when having forbid

13:24

it's on the non coronary gut,

13:25

that's an important measurement for you to remember.

13:28

The aortic valve calcium volume is really not predictive of

13:31

that, but again, the oversizing is, has a lot to do

13:35

with this because, you know, getting an accurate measurement

13:37

of that annuals with that calcium

13:38

can be a little bit more challenging.

13:40

Now, you will have in this course, uh, the opportunity

13:45

to practice this concept

13:46

of sizing an aortic annulus in both, uh, normal

13:50

tri leaflet aortic valve,

13:51

but we also included challenging bicuspid aortic valves.

13:54

Aortic bicuspid aortic valves have a little bit more

13:57

of a challenging approach

13:58

because they're asymmetric in that asymmetry.

14:01

Oftentimes the simple, uh,

14:05

machine assisted approach may not necessarily give you

14:07

always the best alignment of the annulus,

14:09

meaning you will likely get an initial annulus measurements

14:12

using the machine

14:14

or the software to kinda align your leaflets where it needs

14:17

to be, but you will need to take that extra step.

14:19

Once when you have set your plane in motion,

14:21

you're gonna have to bring your crosshairs into the middle

14:24

and manually align to ensure that

14:27

that annulus is completely, uh, aligned in a way

14:30

that it's not opposite

14:32

or belong to, to, uh, an an asymmetric enlargement

14:37

of one of those leaflet cuffs, which you can't do

14:40

once you have made your plan your annulus plan

14:43

and you have measured that number

14:46

and you have gotten, this is my annulus measurements.

14:49

The next big step in the assessment is measuring the

14:53

coronary osteum height

14:55

and the sinus of Salva height in relation to this plane.

14:59

So the way you measure the coronary osteum height,

15:02

it is measured directly perpendicular to the annular plane,

15:05

and you're gonna do this from the lower edge

15:07

of the coronary osteum to the annular plane.

15:11

It's very important that as you scroll through your image,

15:13

particularly those modified orthogonal views,

15:16

that you really find the root

15:18

or the lower edge of that left main in

15:20

that right coronary artery

15:22

where they are at the highest point to be able

15:25

to make that measurement.

15:26

Most modern softwares allow you

15:28

to make this measurement relatively easy

15:29

and they have the advantage of locking this plane

15:32

so you don't have to worry about moving it while you're

15:34

making a measurement, or heaven forbid you have alignment

15:37

changes during that process.

15:39

So why do we care about that?

15:40

Obviously, coronary occlusion used to be a thing

15:43

before we had ct, but nowadays it's extremely rare.

15:47

But if you do have coronary occlusion,

15:49

it is significantly a high risk problem

15:51

because it's associated with like a 40% chance

15:53

of 30 day mortality that's extremely high.

15:55

So what is the risk for coronary OS when it comes

15:58

to TAVR assessment?

16:00

And that has to do with an osteo height

16:01

of less than 10 millimeters from the annulus,

16:04

but also the sinus

16:06

of Salva a mean diameter being less than 30 millimeters.

16:09

So we often wanna measure the sinus of SALVA

16:14

to ensure that you don't have any

16:16

of these contraindications for that risk.

16:18

Other things that can contribute to your risk

16:20

of obvious coronary obstruction have to do

16:21

with the native valve cusps,

16:23

especially if they're heavily calcified,

16:25

if they're quite elongated.

16:27

If we have a shallow sinus of sva, again,

16:29

this definition varies, it's not very well defined.

16:31

And then obviously the oversight type of susis

16:34

and more importantly, if you end up implanting the

16:37

prosthesis a little bit higher than

16:38

where the annulus itself is located.

16:41

So when it comes to the coronary osteo height

16:43

and the sinus of Salva,

16:44

you should measure the custo cus custo commissure

16:47

measurement in a parallel to annular plane orientation.

16:50

I also like to measure in an orthogonal plane,

16:52

so I provide my measurements in both angles,

16:55

but unlike when we measure coronary ct, where we do a sinus

16:58

to sinus measurement for TAVR patients in

17:01

that systolic phase, you wanna measure sinus of SALVA

17:04

to commissural uh, plane.

17:07

Last but not least is the synott tubular junction.

17:09

This is the height of the sinuses of Salva

17:11

and you obtained it from the annular plane

17:13

to the lowest point of the synott tubular junction.

17:15

You can do this mostly, I usually do this in my reports

17:18

for the left and right coronary sinus, less so

17:21

for the non coronary cuss,

17:23

but it's some of the important measurements

17:24

that you have to kind of measure.

17:26

Last but not least, you also have to measure the OT tubular.

17:31

And this diameter is measured in a double oblique plane,

17:34

not parallel to the annual plane as a single measurement,

17:37

meaning it is okay to unlock that annual plane

17:40

to get into the actual left ventricular

17:42

and the junction to get a measurement directly on it

17:45

to ensure that you're not having off measurements.

17:49

Last but not least, the ascending aorta is measured on a

17:52

double bleak multiplier reform to ensure that there's any

17:55

apathy that could potentially affect the delivery

17:57

of the device, but as well as potentially lead

18:00

to any challenges in getting the angle put in place.

18:03

So why is cardiac CT used to prevent T complications?

18:07

A lot of the complications end up being

18:09

the delivery of the device.

18:11

One of the most common ones has to do

18:13

with this infamous aortic root angle.

18:15

This is the angle between the horizontal plane

18:19

and the plane of the aortic annulus.

18:21

So essentially you're gonna have your annulus plane in place

18:23

and you're gonna measure a direct horizontal plane to

18:26

that plane and that degree in orientation.

18:29

You can do this on a 3D reformatting

18:31

or you can do it on your orthogonal view, uh,

18:33

after you do your annulus assessment.

18:36

But it's important to know that it's a thing.

18:37

This is a lot has to do with the evolut valves

18:40

or the self-expanding valves where aortic root angulation

18:45

of more than 48 degrees was associated with, uh,

18:48

lower device success, meaning more leaking,

18:51

more post dilation embolization,

18:53

and the need for a second valve implantation, right?

18:56

But it's not necessarily something

18:58

that is associated in clinical outcomes in any of the recent

19:02

retrospective studies.

19:03

What that you need to be aware of

19:06

that sometimes may be asked of you in your, in your reports.

19:10

Now, when it comes to valves,

19:11

there's two valves used in the United States.

19:13

I know some of you're working internationally,

19:15

so you may have access to different valves,

19:17

but you know, these are the most commonly, most studied

19:21

and highest quality of data type of valves available.

19:23

And these are the balloon expandable valves for sapiens, um,

19:28

and it's Edward Science

19:29

and then the self-expanding valves for the Evolut Pro

19:32

and the evolut effects from Medtronic.

19:35

They are bovine pericardial valves for the sapiens

19:37

and they come with an intra annular annulus of 20, 23, 26

19:42

and 20 millimeters while the, uh, sep uh, Medtronic, um,

19:47

evolu valves are porcine pericardial valves with a s annular

19:51

sizes of 23, 26, 29 and 34 millimeters.

19:54

Now, when it comes to CarX CT for TAVR sizing,

19:57

we really like to use an annulus area based

20:00

algorithm for consistency.

20:01

So when you provide the measurements, yes,

20:03

you'll provide largest, smallest diameter,

20:06

but it's that area that is tends

20:10

to be the better predictor for any type

20:12

of like secondary endpoints like annular rupture

20:15

and more importantly, avular regurgitation.

20:17

That's more than mild as you can see.

20:19

Uh, it's important for us to kind of have

20:21

that consistent assessment.

20:23

Now, when it comes to oversizing,

20:25

you often hear this measurement, you'll always hear like,

20:29

what's the oversize oversized percent,

20:30

oversized percent of that.

20:32

When it comes to that, it means that a TAVR valve

20:34

that is larger than the native annulus, what's

20:36

that percentage going be?

20:37

Meaning if you open up that valve,

20:40

whatever bioprosthetic valve it is that you're going use

20:42

to its nominal measurement,

20:44

and you divide that by the annular measurement as a fraction

20:47

or a percent, that's going

20:49

to give you the percentage oversizing,

20:51

you can do that manually.

20:52

But most of days nowadays we use this app called the TAVR

20:56

sizing valve to kind of get us a rough estimate of

20:59

what the oversizing is going

21:00

to be based on your annulus measurements

21:03

and more importantly, provides you information about the

21:05

science of Salva diameter as well as the

21:08

of Salva height in relation to that.

21:10

Now, while this is not an FDA a approved, uh, application

21:14

for you to make decision, it's definitely a great guide

21:17

for you to get initial assessment to kind

21:19

of verify measurements, to ensure that your sense

21:22

of salva diameters yours of El Salva heights, as well

21:25

as your oversizing measurements

21:27

are to where they need to be.

21:28

And if you need to kind of double check your math

21:30

or corrections, oversizing is important

21:32

and it's something that we usually do,

21:34

but we just don't do too much of it.

21:37

You wanna oversize it in just the right amount,

21:39

particularly find that sweet spot.

21:41

But if you do that oversizing of more than 15%,

21:44

that's when you start having issues.

21:46

When you get closer to the 20%, that's

21:49

where you have a higher risk of annual rupture

21:52

where you know you don't have a, you don't,

21:54

you're gonna have a significant bad

21:56

afternoon for those patients.

21:57

So when it comes to this, the oversizing of the prosthesis,

22:00

as you can see on the graph, you have much, much better, uh,

22:04

time with no no having issues as far as, uh, ruptures

22:09

or any other complications when you maintain it in that 10

22:13

to 15% in oversizing.

22:16

Now we use 3D TAVR for this

22:19

because it is more predictive of who's going

22:23

to develop more than mild per ular regurgitation, right?

22:26

If you just past it on two dimensional analysis, it tends

22:29

to underestimate the annuals area as low as much as 20%.

22:33

And this underestimation of the annual size can often leads

22:37

to a lot of significant ular regurgitation,

22:40

which is something that we don't want to see.

22:42

So when you have the valve leaking

22:44

after TAVR replacement, that does lead

22:47

to the patient having bad outcomes even

22:49

after the valve replacement.

22:50

So that's something we'd like to avoidable possible.

22:53

The oversizing index's an important measurement like

22:57

what we mentioned, you know, that oversizing percent is, uh,

23:00

so one of the things that we utilize to kind

23:02

of get us a better sizing to reduce this location

23:07

now paravalvular

23:08

or valve regurgitation in tavr, it's,

23:11

it's relatively lower now as we're getting better, uh,

23:14

with the technology.

23:15

But what we know is the mortality tends to be higher,

23:18

particularly from any cause depending on

23:21

the severity of per value or leak.

23:22

As you can see here, if you start with mild to severe,

23:27

yeah, that, that's gonna be significantly higher as compared

23:30

to non to trace amounts of regurgitation.

23:32

That's why taking the time to do this,

23:34

and even if you have a vendor doing the decisive

23:37

for your TAVR valves, it's important for you

23:39

to do your own measurements to check in order to address any

23:42

concerns or, or potential challenges

23:45

or issues with, with your,

23:48

um, with your patients.

23:51

Now, when it comes to comparison oph echocardiogram, yes,

23:55

you can kind of utilize this

23:58

and comparing it to what they found in open heart surgery

24:01

and they found that, you know, cardiac CT tends

24:03

to overestimate the annular diameter, but not significantly.

24:06

It provided the smallest margin

24:08

of error when you compare to other modalities.

24:10

But more importantly, uh, cardiac CT

24:13

provided the most accurate measurements

24:15

for the tic annulus diameter.

24:17

And that's one of the reasons why we use this d

24:21

as the IM modality of choice.

24:23

Now, when it comes to predictive vascular access

24:26

complications, uh, cardiac CT

24:29

is an important thing for a couple of things.

24:31

It's going to help you assess the vessel size.

24:34

We used to have this sheet to femoral artery ratio.

24:38

Nowadays the sheets themselves have gotten so small

24:40

and the device is so much more easily deliverable

24:43

that this has become less of an issue,

24:45

but it's something that's important to note in your report.

24:49

Last but not least, the degree

24:50

of calcification in this vascular access areas is important,

24:53

where if you have a more than 270 degrees calcification

24:57

around the vessel, that increases the risk

24:59

of having vascular complications.

25:01

Last but not least, the tortuosity

25:03

and immoral tortuosity in a lot of these patients tends

25:06

to be a more than 90 degrees turn in any vascular bed.

25:10

So as much as we'd like to align

25:12

the multiplanar reconstruction into a straight line to kind

25:15

of make measurements, I'd kind of encourage you

25:17

to always provide a three dimensional models,

25:20

whether looking at the axial images yourself to ensure

25:22

that even tortuosity

25:24

or more than 90 degrees turn in the,

25:26

the vasculature is not something that's present.

25:30

Okay, next we're gonna move on to cardiac CT and

25:33

after TAVR assessment where patients

25:36

who have had the valve tend to have issues.

25:38

And one of the most common indications for evaluating, uh,

25:42

valves with CT

25:43

after they've had TAVRs has to do with this concept

25:46

of hypo leaflet thickening.

25:49

We have a lot of these findings in some of the cases that we

25:53

provided for you with this particular topic to kind

25:56

of get you to practice and evaluate how it's

25:58

so hypo attenuated.

25:59

Leaflet thickening has to do with the degree

26:02

of involvement from the base of the leaflet and,

26:05

and a multiplayer eye, uh, evaluation

26:08

of the leaflets once they're aligned to the center

26:10

of the leaflet itself.

26:12

As you can see, the degree of stenosis tends to be created

26:15

by mild, moderate, severe in the in, depending on the amount

26:20

of thickening as the valve leaflet itself progresses,

26:23

meaning that if it's more than 75% of the leaflet length,

26:26

that tends to be pretty severe.

26:27

As you can see on this illustration,

26:29

when you have hypot annuating leaflet thickening,

26:31

if there is restricted mobility, uh, that's limited

26:35

beyond the base, meaning more than the base

26:39

for less than 50% of the base all the way extending

26:42

to the entire leaflet itself,

26:43

you can actually grade the degree of leaflet motion

26:46

and we call that attenuation affecting motion or ham.

26:51

I know we have halt in ham,

26:52

but it's one of those things that you gotta remember

26:55

to make sure that if you see a degree

26:56

of hyper continuation leaflet thickening, not just

27:00

evaluate this on the systolic phases,

27:02

but you're also one, one to kind of see its motion

27:04

through both s Sicily

27:06

and diastole to assess if it's, you know, grade three,

27:09

grade four, or if it's something as minimal as grade one

27:12

or literally grade zero with no involvement.

27:15

As we have more and more experience with this valves,

27:17

we've come to understand

27:19

that the actual three dimensional morphology

27:21

and geometry of these valves, meaning we'd like

27:24

to expand them as best as we can,

27:26

but sometimes the calcified leaflets

27:28

and the patient's anatomy limit, the leaflet expansion to be

27:31

where it is, tend to account for a lot of this halt.

27:34

A lot of it has to do with the, you know, what we describe

27:37

as, um, volume index,

27:40

meaning the volume at which the leaflets are supposed

27:43

to be non deformed, having adequate leaflet expansion

27:47

and how that relates to the development of halt.

27:50

Meaning if those leaflets are not fully expanded as

27:53

how they should be, meaning they have leaflet expansion,

27:56

that tends to be asymmetric

27:58

as you can see in these illustrations.

28:00

Um, then, uh, we're gonna try to, you know, potentially

28:05

as assume that this is where one of the factors

28:07

that are contributing to,

28:09

to the development of this condition.

28:11

Now, once you have had developed halter,

28:13

you have bioprosthetic valve degeneration.

28:16

We're talking at a couple of valves

28:19

where you could potentially be looking at,

28:21

but putting a valve to replace it, the targets

28:24

for which this question is gonna be brought upon are going

28:26

to include valves that were surgically put in,

28:28

whether they stented or stent less

28:30

or transcatheter valves when they failed.

28:33

Now, unlike native valve replacement where the risk

28:37

of coronary occlusion is relatively low, less than 1% here,

28:42

the rate of coronary occlusion, as you can imagine,

28:44

is significantly higher because you have native leaflets

28:47

that are, that not native leaflets with the surgical valves,

28:51

but you have leaflets with the bowel prosthetic valves

28:53

that are going to be a little bit more unpredictable as well

28:56

as the position of the valve

28:58

and how that was actually surgically implanted

29:02

and the ken position of that valve in the relationship

29:05

to the aortic group dimension.

29:07

So when you look at the valves in this particular case,

29:10

the implantation of this is gonna use

29:14

the bioprosthetic valve as a scaffold.

29:17

And essentially what you're gonna be creating is a covered

29:20

cylinder or a covered stent from the overlying

29:23

bioprosthetic valve leaflets.

29:24

That's what's gonna make your quote unquote

29:25

stent coverage, right?

29:27

Depending on where your leaflets,

29:30

how long does native leaflets of

29:31

that bioprosthetic valve are, where the type of valve

29:34

that you're implanting, meaning where the actual

29:37

leaflets from the new bioprosthetic valve are going

29:40

to be located, located

29:41

and the relationship of the coronary sinus is,

29:43

is gonna be the determinant for that.

29:46

The reason why we kind

29:49

of look at this importantly is we want to ensure that

29:52

where this newly placed valve bioprosthetic valve

29:57

is in position to the coronary ostia is going

30:00

to determine the risk of obstruction.

30:02

Meaning you're going to simulate

30:04

and the folks at terra recon have kind of allowed us

30:06

to use this software for your cases to kind

30:09

of simulate the implementation of this valves

30:11

and bioprosthetic valves that are dysfunctional to kind

30:14

of simulate where this valve would sit in relation to the

30:19

OTE of the coronary coronary artery that exists there.

30:24

That distance or that potential space or gap that exists.

30:28

The virtual valve to coronary distance is the one

30:32

of the most important concepts when it comes

30:35

to valve in valve placement.

30:37

This is the idea that the virtual valve

30:41

to the coronary distance is gonna account

30:43

for the anatomical distortion

30:44

and it's used to predict the distance from

30:46

where this frame is going to be in relation

30:48

to the coronary off office.

30:49

And this is the only independent predictor that we have

30:52

so far for the presence of coronary obstruction.

30:55

Meaning we know when that virtual to coronary, uh,

30:59

this is less than four millimeters

31:02

or equal to four millimeters, the risk

31:04

of coronary obstruction is significantly high

31:06

and it can be restricted.

31:09

Now we do this for both the right coronary artery

31:12

and the left main artery.

31:14

If and only if the posts of the bioprosthetic valve

31:19

extend to or are above the level of the coronary orifice,

31:23

if the coronary or arteries originate well

31:26

above this coronary post, your risk of

31:28

that is almost non-existent.

31:29

So what do I mean by that?

31:31

When you look at any type of surgically placed valve,

31:35

you need to ask yourself, is the valve stented or not?

31:38

If it's a stented valve, you simply need

31:40

to ask your question, is the coronary OTE above those posts?

31:45

As you can see in the illustration to your left

31:47

in this particular valve, the answers no.

31:50

You can see that the coronary OS is well below the top

31:53

of the post, meaning here, the risk

31:55

of coronary obstruction is gonna be significant.

31:57

Whereas in this valve where the coronary,

31:59

the valve posts are well below the osteum of the left main,

32:03

there's virtually no possible way for this valves leaflets

32:09

of obstructing the coronary artery

32:12

because no matter how tall they are, they are always going

32:15

to hypothetically reach only to the top of the stent post

32:18

'cause that's how they were engineered.

32:19

If you have stent valve,

32:21

you just do the regular coronary height

32:23

and science of salva assessment.

32:25

Now, when it comes to valve in valve tab

32:28

or particular when you're putting balloon expanding

32:31

or self expanding valves in a TAVR valve, a lot

32:34

of this concept becomes the new skirt

32:36

or the needle skirt concept where based on

32:38

where this new valve is going to be in relation

32:41

to the actual height of the previously placed valve is going

32:44

to be determined by both the stent frame

32:46

and the leaflet position.

32:47

This can get a little bit more complicated,

32:49

but it all has to do with what's called the risk plane.

32:51

Meaning depending on the type of valve that it's

32:57

have a risk plane that's going to be effective.

32:59

For example, smaller sapien valves can have a risk plane

33:04

anywhere between 50 millimeters in height up

33:06

to 22 millimeters depending on the valves,

33:08

meaning the larger 29 millimeter valves are going

33:11

to have the highest, uh, risk plane for the evolut valves.

33:15

Even though the valves themselves tend

33:17

to be different sizes here

33:19

and different sizes here, their height

33:21

of this risk plane tends to be consistent.

33:23

So for da, it's release, it's always 26 millimeters,

33:25

meaning when you do a valve in valve implantation,

33:28

you're going to simulate this risk plane or the neo skirt.

33:32

Different types of gen valves

33:33

or the, uh, lotus valves obviously have different

33:35

measurements, but are provided those.

33:38

And the idea of this is to try to see

33:40

how the index transcatheter valve is going to be,

33:43

where you're going to implant

33:45

that trans new transcatheter valve in relation

33:47

to both a high implant or low implant.

33:49

How you're gonna get that aligned to ensure that the,

33:52

the coronaries can be accessed later, how you're going

33:54

to expand it, and more importantly, how that valve is going

33:58

to look like if you put a self ex a balloon expanding valve

34:02

or a, or a self expanded valve within a

34:04

self expanding valve, right?

34:07

So a lot of this has to do with, with what those are going

34:10

to look like and what those nodes, meaning where

34:14

along these little notes in the valves,

34:16

you're going to be persistent.

34:17

Now we're not gonna torture you with that

34:20

because this is quite the advanced concepts

34:22

and a lot of the times it's not something

34:23

that you're gonna come across

34:25

or just something that you're gonna have to do by yourself.

34:27

But this is more like an understanding of

34:29

how different positions that Neos

34:34

height are gonna

34:40

have, you know, the risk of to potentially oc the valve

34:44

as they hang in different

34:45

positions as it's implanted, right?

34:46

So other things that you're going to need

34:49

to know is sometimes when there's no way to avoid

34:52

that valve obstruction, meaning those leaflets aren't going

34:55

to potentially occlude the coronary arteries, you're going

34:58

to need to kind of potentially plan

34:59

and help your interventionalist plan for either, you know,

35:03

what is balloon before laceration type of approaches

35:06

where they're going to create lacerations

35:10

in the valve leaflets from the

35:15

previously existing

35:17

or pre void the obstruction of the coronary arteries.

35:19

And again, a lot of it has to do with

35:21

what the leaflets lengths were

35:23

and more importantly, how that neos concept applies to

35:27

and how they're going

35:28

to determine both the implant location, the alignment

35:32

of the valve, the type of transcatheter plant development,

35:35

and more importantly, the distance

35:37

to not just the coronary sinus,

35:38

but the synott tubular junction in relation to to the valve.

35:43

So that's all the concepts that we're gonna cover today.

35:46

Obviously you're gonna have this recording

35:49

and I encourage you to kind of go through it.

35:51

Uh, we provided you with a template, a fillable PDF

35:56

uh, template that I would strongly encourage you to do

36:00

and follow along and annotate your measurements

36:03

as you're building your report.

36:04

Obviously you're gonna have a report

36:06

and you can try to dictate your measurements as you go,

36:09

but I would strongly encourage you

36:10

to use those PDF templates that would make

36:13

that are fillable, tell you where the measurements need

36:15

to be to kind of collect all the possible measurements

36:18

that you'll need in order to make your template dictated

36:21

for when you do your own valve assessment.

36:23

These valve cases are often the most challenging cases in

36:26

the course, and that's why we encourage you

36:28

and give you the slides your weeks in advance

36:29

before, so you have plenty of time to review the concept,

36:33

ask questions, read the references

36:35

provided for you in this lecture, as well

36:38

as any questions you may have with the cases.

36:41

If you come across challenges with those haver cases

36:43

where you want us to discuss office hours, make sure

36:47

to reach out to Courtney so that she can let us know

36:50

and we can address those as best as we can.

36:53

But feel free to reach out

36:54

with these particular challenging cases

36:56

because then they're definitely

36:57

the hardest part of the course.

36:59

Questions.

37:01

Yeah, if we don't have any questions,

37:03

we can conclude for today.

37:05

Uh, just a reminder where

37:06

to find those report templates when you log into the course.

37:10

The main training, uh, course with, uh, the course

37:13

that has the weekly cases in the start here folder.

37:17

The second topic is called report template examples.

37:20

You will find that TAVR template located there.

37:23

I'm also happy to email it out to everybody

37:25

so you have it handy for the next round of cases.

37:28

Um, thank you again everybody for attending.

37:31

Um, just a reminder, the next live session is

37:33

for office Hours week seven, which is this coming Tuesday,

37:37

June 4th at 1:00 PM Central Time.

37:40

Um, and as always, listen if you have any questions

37:42

and thank you again for attending.

37:43

Thank you again, Dr. Pun. Goodbye everybody.

37:48

Take care.