I'm sure many of you in the audience
are afraid that I'm going to try to convert you
into being echocardiographers at this late hour tonight.
Well, I'm not going to do that.
I'm going to try to convert you into being
3-D echocardiographers.
So, I don't know if it's possible to please
have the lights down more in order
to display the images better.
So I've decided to answer the specific question, what
does 3-D echo imaging offer tricuspid valve surgery.
I'm going to use a very singular case example.
A case that many of you-- or all of you in the audience may have
had a similar case--
to illustrate very specific key concepts.
These specific key concepts relate
to 3-D echocardiography's ability
to evaluate the leaflets, the chordae, the papillary muscles,
the entire tricuspid valve apparatus
and it's synchronous motion in three dimensions.
I'll discussed briefly the ability
to measure the vena contracta to estimate regurgitation,
the ability to measure effective orifice area for stenosis,
and then the application of 3-D echo
to measure right ventricular volumes and ejection fraction.
So this was a eight-year-old male
with hypoplastic left heart syndrome, who
had had a fenestrated Fontan.
And he was in an ICU on milrinone and diuretic therapy.
And he was noted to have significant RV
dilation and significant dysfunction,
and was noted to have severe tricuspid valve regurgitation.
His outside diagnosis had been that he
had anterior leaflet prolapse secondary to annular dilation.
I'm sure a very similar case to many of our cases
we all take care of.
So here's a typical two-dimensional echocardiogram.
And you can all appreciate what really looks like prolapse
of the anterior leaflet.
And that's what this patient was thought to have.
Clearly, we all can see the very severe tricuspid regurgitation.
The RV was significantly dilated and dysfunctional qualitatively
by this two-dimensional imaging.
But in this patient who was in the ICU, we went up to image
him with 3-D echo and this is just a live 3-D image,
just put the transducer down.
And what was most notable here-- because we can see
in the three-dimensional perspective--
was that this leaflet, it's not just
prolapsing it's actually scalloping,
perhaps billowing, or perhaps even flail.
So we did a 3-D volume data set here,
and what was most important was that by just changing
the imaging plane you could see the very significant scallop
of that leaflet.
Now here, because it's a three-dimensional data set,
if we rotate the plane and look at the RV from the apex up
towards the under leaflet of the valve,
you can see a portion of it clearly
protruding up into the right atrium,
or almost billowing up there.
And then you can see a significant zone
of non-coaptation between this anterior
and the septal leaflet.
We started to get the impression that the septal leaflet was
severely tethered.
So here, we can see the cross-sectional image
of the valve from below.
And you can see a very significant zone
of non-coaptation between the anterior
and the septal leaflet.
When we went to the 3-D color format,
we could see there was severe tricuspid valve
regurgitation and the format to the right, well-rotated around.
And in three dimensions, you can see
it was a very large jet of regurgitation.
Now the importance of this slide is that in three dimensions,
you can truly measure the tricuspid valve annular size.
So there are two, or a longitudinal simultaneous cut
planes- a four chamber and a two chamber view.
And then you can see the blue cross-sectional plane
that we can put precisely in the region of the annulus.
And we get an en fos cross-sectional view
of the annulus, which we can then trace and evaluate
the annulus as it truly exists in three dimensions.
Now we can also do that for the vena contracta.
The vena contracta a direct measurement
of the area of regurgitation.
And this was based on work done and presented in the American
Society of Echocardiography.
And here's just an R patient from their transthoracic
echocardiographic view.
You can get a three-dimensional format of the regurgitation,
and again, in longitudinal segmented two-dimensional views
you can precisely place your cut plane
in the area of the vena contracta,
and you can angulate-- so you're directly in alignment--
with the regurgitation.
And again, you can planimeterize that area specifically
as it truly exists.
Now, Brian Soriano in our laboratory several years ago,
published a position paper in which
we measured RV volumes by 3-D echo and compared those to MRI.
And on the base of this paper, we've
been able to use and measure RV volumes,
which we did in our patient.
And this is used in the semi-automated detection
algorithm.
We measured the RV volume at 160 ml per meter squared,
with an ejection fraction of 47%.
Well based on these two-dimensional images,
we had the clear-cut and three-dimensional images.
We had the impression-- and I showed these to Dr. del Nido--
that the leaflet was not just prolapsing
because of RV dilation.
But it was flail.
It seemed to be moving freely back and forth.
So the decision was to go to the operating room.
And you can see in this two-dimensional image,
the motion of the anterior leaflet of the mitral valve.
But we had in the concept of our mind
that this wasn't just typical prolapse,
but this was perhaps a flail leaflet.
We confirmed the severe tricuspid valve regurgitation.
And then we went to 3-D imaging by transesophageal epicardial
echo in the operating room itself.
And these are segmented images that we
were able to make in the operating room.
And I could say, hey Pedro, take a look at this image.
And he's used to me doing that very often.
But in this image, what you're doing is
you're looking down onto the tricuspid valve
from the right atrium.
And you can see the significantly proximal
tethered septal leaflet right here.
And you can see the very extensive zone
of non-coaptation.
This image actually surprised me when
we created it, because I've never quite seen it.
But this is like a longitudinal view of the tricuspid valve.
And here is the severe flail portion
of the anterior leaflet.
But most importantly, we could see the zone of non-coaptation
and the very tethered septal leaflet.
But the other thing we could see,
is the longitudinal extent of the papillary muscles
to the chordae tendineae to the under-surface of the valve.
And we could see chordae posterior laterally,
but non-anteriorly on to the under-surface of the valve
there.
In two-dimensional imaging, because you'll always
have at any point in time a singular cut plane,
it's virtually impossible to see the papillary muscles,
the chordae, and the under-surface of the valve
leaflets at the same time.
And you can't really see the synchronous motion of that.
But in a three-dimensional format,
where you actually have depth, you
have the ability to see all those parameters
simultaneously.
I think the importance in our patient
here, was that there was the possibility, knowing that there
were a lack of chordal attachments to the leaflet,
and knowing that you had a severe flail component
of the leaflet, that you could repair this valve
rather than replace it.
And so we could demonstrate in the operating room to Dr. del
Nido that there were absence of both primary and secondary
cords to that anterior leaflet.
There was a lack of chordae to the edge of the leaflet
and even to the body of the leaflet.
So the beauty is we could take a cut plane right
below the leaflet, right up to it,
and clearly show no chordal attachments up to this anterior
portion of the leaflet.
Now after repair, in which Dr. del Nido was
able to close the commissure between the anterior septal
leaflet, put in a ring, and then attach an artificial cord
to the anterior leaflet.
As you can see, there was much improved leaflet coaptation
with a good coaptation height.
There was the absence of significant tricuspid
regurgitation, with good tricuspid inflow.
And then in the operating room, in this longitudinal view,
we could see the chordal attachment--
this artificial cord going from the papillary muscle
up to the chordae tendineae.
Importantly, we could turn it on its side and segment closer in,
and we saw the absence of the severe flail anterior leaflet,
with a very good length of coaptation.
Here is the annular ring.
And again, because of this being 3-D echo,
we could now look down onto the annulus from the right atrium.
We could see the U-shaped configuration of this annular
ring and the absence of any perivalvular leak.
Now importantly, that was in the operating room.
So what did it look like before discharge?
Did it still hold true?
Now of course all of know your transthoracic imaging isn't
that good in the post-operative patient,
but we clearly could see the absence
of the flail, anterior leaflet, there
was no longer any significant tricuspid valve regurgitation.
And importantly, when we looked at these images
from the RV apex, we could see the chordal attachment.
It was directly attached up to the under-surface
of the tricuspid valve.
By three-dimensional color flow imaging,
there was absence of tricuspid regurgitation and a very good
inflow jet.
But again, similar to the other measurements we had made,
we could now truly measure the effect of orifice area.
As you all know, especially for the right side,
the gradient may not give a true indication of the severity
of the stenosis.
So what you really would like to do,
and what we should be doing as a pediatric community,
is talking about effective orifice area.
So again, because you've got the entire data set,
and the volumetric data set here,
you can segment out simultaneous two-dimensional views.
So this is the long axis four chamber view,
long axis two chamber view, and you
can put your cut plane in blue directly
across the effective orifice area,
look at it directly on phos, trace it,
and measure the effective orifice
area as it truly exists.
And importantly, without having to go to another procedure like
an MRI-- you can imagine it would be difficult to sometimes
get an MRI in an immediate post-operative patient--
we could measure his ventricular volumes by 3-D echo.
And note, there was a marked reduction
in the RV volume-- nearly 35%.
The ejection fraction had gone down,
which we clearly attributed to the sudden release
or take away of the low resistance tricuspid
regurgitation, making the ejection fraction go down.
Subsequent imaging will hopefully
show that it goes back up again.
So the most important thing I wanted
to share with you using the key example,
is that you can use 3-D echo to truly evaluate
the tricuspid valve anatomy, the function, and the RV volumes
and ejection fraction.
Thank you very much.
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