Successful Repair of Degenerative Mitral Valve Disease Depends on Recognition of Etiology - SD

Introduction

My name is Dr. Gregory Fisher.
I'm the co-director of Cardiac Anesthesia at the Mount Sinai
Medical Center in New York City.
And today I'd like to talk about degenerative mitral valve
disease and why exact precise echocardiographic diagnosis
of these lesions is imperative for the surgeon in order
to perform a successful mitral valve repair.
Today I'd like to talk about successful repair
of degenerative mitral valve disease
and how this depends upon the recognition of the etiology
of the lesion by the echocardiographer.

Initial Quiz

First, I'd like to quiz everybody in the audience
and show you two clips.
This first clip that you're looking at right now,
what do you think this represents?
Fibroelastic deficiency with an A two prolapse
fibroelastic deficiency with a P three prolapse,
barlows disease with a P two prolapse, or you're not sure.
The second image that I'd like to show you,
please answer the question here.
What are you looking at? FED Fibroelastic deficiency
with a P two prolapse barlows disease
with a P two prolapse, FED with B leaflet prolapse,
or you're not sure?
Everybody take a minute to think about that.

Importance of Repair Over Replacement

Many patients have a shortened life expectancy
because of the current practice
that is in place today in the United States.
Sur published a paper in the Annals
of Thoracic surgery in 2006, clearly showing
that replacement of the mitral valve is associated
with decreased survival when compared to repair.
And this is true not only for posterior leaflet
but also for bi leaflet prolapse.
Questions that patients frequently have is, well,
is my repair gonna be as durable as a mechanical valve?
And I think that a paper
or the data that David etal showed us clearly
can answer this question.
Posterior leaflet prolapse has an 80% durability
after 12 years by leaflet
and anterior leaflet prolapse are in the mid sixties.
So why is it that we still have a 50 50% chance
for most patients with mitral valve disease
of getting a mitral valve repair?

Mitral Valve Anatomy

Let's look at the mitral valve anatomy first
so we understand something about the complex interactions
of these multiple parts
before we actually look into mitral valve repair.
The mitral valve doesn't only consist of its anterior
and posterior leaflet,
but also of a subvalvular apparatus consisting
of the cortic kina the papillary muscles
and the left ventricular wall, the posterior leaflet is
subdivided into three scallops by two indentations.
There is the P one scallop, the P two scallop
and the P three scallop.
By definition, the adjacent structure
of the anterior leaflet is called the A three segment,
the A two segment, and the A one segment which la
vis-a-vis from the P one.
There is an ant lateral commissure
and a posterior medial commissure as well.
These are important anatomical landmarks
that the echocardiographer must be able to find
and use in order to properly discuss
with the surgeon the pathological
findings of the mitral valve.

Mitral Valve Function and Pathophysiology

The mitral valve function is actually quite simple.
During diastole, the valve has to open allowing for blood
to enter the left ventricle from the left atrium.
And during systole, the mitral valve is supposed to close,
be competent, allowing the blood
to only be injected out into the aorta.
Alan car, Ponte, one of the fathers
of modern day mitral valve repair, came up
with a pathophysiological triad
to help us understand mitral valve disease.
And we can use this as echocardiographers to depict lesions
and dysfunction and use this then to talk to surgeons.
The first thing that we want
to know is what is the etiology?
What's the cause of the valve disease?
What are the result in lesions from this etiology?
And last but not least, what are the dysfunctions
that are arising from these lesions?
Ponte also prescribed a classification for different types
of regurgitation mechanisms.
The type one mechanism is
where we have normal leaflet motion,
which means both the anterior
and the posterior leaflet rise above to the annular plane,
but stay within the annular plane.
The primary problem here is dilation of the annulus,
which means that the zone of coaptation isn't large enough
to guarantee competency.
Type two dysfunction is classically seen
with leaflet prolapse In this type of lesion,
the mitral valve leaflet arises above the plane
of coaptation and a leak occurs.
There are also type three lesions,
which mean there are restricted leaflet motion.
The type three A is where you see a
systolic anod diastolic restriction of the mitral valve.
Leaflets three B is seen in dilated large ventricles
with displacement of the papillary muscles apically,
which impede normal leaflet motion during systole.

Principles of Mitral Valve Repair

So let's take this information.
Let's see if we can understand right now
how mitral valve repair is actually performed.
There are principles to mitral valve repair.
The first principle that the surgeon tries
to do is correct leaflet dysfunction.
So it's very important that the echocardiographer can
properly identify what is actually wrong
with these leaflets.
The second thing is we wanna restore a large
surface of coaptation.
What that means, I'm gonna get into later
on during this talk.
And the third thing is this annulus has
to be stabilized in the systolic position with the aid
of Annuloplasty ring.

Correcting Leaflet Dysfunction

So the first thing is
how do we correct the leaflet dysfunction?
This is a case of a typical P two prolapse where the
viewer can observe here some torn cords.
This P two segment arises clearly
above the plaintiff coaptation.
What the surgeon does here is he identifies the disease part
of the posterior leaflet makes incisions basically a
quadrangular and resection,
cutting it away a sliding plasty.
These sutures that you see along the annulus here
compress the annulus, bringing it together.
And afterwards the surgeon sews up these defects leading
to a competent posterior leaflet.

Restoring Surface of Coaptation

Coaptation surface is extremely important.
The zone of coaptation is seen here
underneath the annular plane.
The surgeon right now is doing an ink test
that means along the, line where the anterior,
the posterior leaflet coapt
after a repair, he's applying some ink.
The left ventricle has been filled with saline.
He's now sucking the saline out of the left ventricle
and will now expect the leaflets.
What you're seeing right now is the tissue that is
beneath the line of coaptation.
The amount of tissue
that you should see here must be at least five
to eight millimeters
that will guarantee a very nice surface of coaptation.
As you can see over here in the left image.

Stabilizing the Annulus

Finally, the annulus must be stabilized
and this is done with a Annuloplasty ring.
The surgeon uses these sizes as seen here in the middle
image here to correctly size the annulus.
And this is done by looking at the size
of the anterior leaflet.
And in this image here, a 28 size
or has been determined to be the correct size.
And this is so then in place.
What you can see right now, the pathological dilation
of the mitral annulus in the AP direction is now corrected
over on the right side by this Annuloplasty ring,
giving the annulus its correct AP lateral dimensions.
And finally, a saline test will be done when everything is
in place to guarantee that there is no residual leak.

Importance of Echocardiographic Differentiation

So why is it important that we
as echocardiographers are able
to differentiate this function
and why does this impact mitral valve reconstruction?
Well, a paper that Dr. Adams
and Dr an Y published recently shows the difference from a surgical standpoint
between barlow's disease and fibroelastic deficiency.
These are the two most common diseases that we see
that make up the classification
of degenerative mitral valve disease.
And you can see here from a surgical standpoint, they
differentiate between barlow's disease
and fibroelastic deficiency.
The Barlow type of valve is classically a very large valve
with multis, segmental, diseased disease
with multis segments prolapsing coming
above the plane of coaptation.
This is an extremely complex valve to repair
and this should only be undertaken by a true mitral master
of mitral valve surgery.
In other words, this type of valve should be referred
to a reference center for mitral valve reconstruction.
Fibroelastic deficiency, on the other hand, is
a uni segmental form of disease.
If you look at this mitral valve on the left,
the anterior leaflet and the P one
and P three aspects
of this valve look completely normal.
The valve is not nearly as large as a barlow's disease diseased valve either.
What one does see is one sees a P two segment here
with multiple torn corde.
This disease, this type of disease is
much more common than a barlow's disease.
And this can be repaired
by an experienced mitral valve surgeon.
This type of lesion does not have to be referred
to a mitral valve reference center.

Differentiation Between Barlow's Disease and Fibroelastic Deficiency

This is a quick breakdown of
what the differentiation looks like between barlow's disease
and fibroelastic deficiency.
Looking at it right now, you can see here the image,
the echocardiographic image on the left, the depicts a valve
with relatively normal looking leaflet segments,
with the exception of this P three flail
where you can see a torn corde, a very eccentric
directed jet.
And looking at the image that we see now on the right,
this was the image that was seen intraoperatively
where we see a P three flail.
The surgeon here is gonna perform a cordal transfer.
He's cutting through one of the cords on the anterior
leaflet, one of the secondary cords,
and he's going to attach this cord now to the disease
to P three
guaranteeing that the excursion of this segment is correct,
he now does a saline test
and you can see that there is no residual prolapse
and no excessive restriction.
Barlow's valve disease, on the other hand, is very complex.
The viewer can see how this whole valve,
the anterior leaflet and the posterior leaflet
just bulge up.
And looking at the echo picture on the right side,
this is multis segmental disease.
There's also some tort and corde here,
but it's a much, much larger valve.
So when the surgeon decides to repair a barlow's valve, one
of the most important things is that he has
to respect the height of the anterior leaflet in order
to avoid Sam.
So you can see right now on the right side,
a 40 sized ring was placed.
And in addition, what the surgeon needs to do is the post,
the height of the posterior leaflet is reduced in order
to guarantee that the line
of coaptation will be displaced more posteriorly.
All these efforts are done in order to avoid SAM
or keep the risk of SAM at a minimum.
So this is the result that we see after a barlow's valve.
You can see that the anterior leaflet is very tall,
the posterior leaflet has been shortened
and there is no sign of sam.

Probability of Successful Repair

So what's the probability of successfully repairing one
of these degenerative valves?
And like I went into
before, it really depends upon the experience
of the cardiac surgeon.
If you have the classic posterior leaflet P two prolapse,
an experienced cardiac surgeon should be able
to successfully repair this valve.
If you look at a barlow's diseased valve, on the other hand,
there's a very, very high likelihood that if you do not go
to a reference mitral valve surgeon
that you will not get a repair,
but you will get a mechanical valve.
A reference mitral valve surgeon,
however, should still be able
to repair this valve in the high percentage of the time.
I would say 80% or higher. So what does this mean?
If you have straightforward fibroelastic deficiency
with a posterior leaflet prolapse,
an experienced surgeon should be more than capable
of repairing that valve.
A barlow's diseased, a young patient,
an asymptomatic patient by leaflet prolapse.
Probably the best thing for the cardiologist in this
situation to do is refer this patient
to a reference surgeon.

Advantages of Large Annuloplasty Rings in Barlow's Disease

Another paper that Dr.
AB Adams brought out from our institution was depicting the
advantage of using large annuloplasty rings in patients
with barlow's disease.
All patients in this cohort, which were 67 patients,
received successful repair
with these large Annuloplasty rings.
And you can see here the discharge data from the
echocardiographic exam that from the 67 patients,
only five patients had mild signs of mr
and most of them, 93% there were no mr
or only one plus of the 67 patients,
there were no mortalities.

Quiz Answers

So let's go back to our question again that we were asking
what are these echo findings consistent with?
Well, you can see here
that this valve looks relatively normal with exception
of this P three flail.
So this would be number two FED with P three prolapse.
The second question that I asked, you can see here,
this is a giant valve with a cul-de-sac with a prolapsing
of multiple segments
and also a very thickened posterior leaflet
and a very tall posterior leaflet.
This would be a barlow's disease with a P two prolapse.

Advancing the Field with 3D TEE

So one of the questions that we have to ask ourselves
as echocardiographer is how can we advance our field
and how can we make imaging even easier
for the non echocardiographer?
One of the great hopes is real-time imaging
with three-dimensional TEE.
You can see here on the left is a real-time
three-dimensional image taken of the patient
that I've been showing you throughout the talk depicting
very clearly a P three flail.
You can see the P three segment coming
above the coaptation plane
and you can even see the torn cord coming nicely into view.
Over on the right side, you can see what we saw
after we put the patient on cardiopulmonary bypass
and opened up the left aum.
This is what the surgeon saw.
It's remarkable how closely the two
images resemble each other.
I'd like to show you now a barlow's valve here from a two
dimensional imaging plane where you can see, it's hard
to see if this is really a barlow just
because of the two dimensional image.
Is it large? Yeah, it's a fairly large valve.
But to really be sure once you see the three dimensional
image, I think everything becomes very clear.
The advantage of this real time three dimensional image is
you actually see how all six segments of this valve clearly
prolapse into the left atrium really making
this quite remarkable.
This is a valve here, a P two prolapse,
which we see on two dimensional echocardiography.
I'd like to show you the three dimensional image
Which you can see very nicely.
The resolution is absolutely incredible.
Once again, looking at this valve,
you can see the anterior leaflet as well as P three
and P one are very normal looking.
The only pathological finding is this P two prolapse, to show it to you from a different angle.
This is a view looking in from the lateral commissure.
You can see the aorta is here in front.
And you can see how the P two segment here cleanly comes
above the line of coaptation.
One of the remarkable things that can also be done with software that is included in these real time three
dimensional packages is the valve can be reconstructed.
And this is the image that we were looking at before.
And you can see how the valve, the anterior leaflet
as well as the posterior leaflet, P three
and P one all lie within the plane of coaptation.
This reddish zone here is the P two prolapse,
red meaning coming above the coaptation plane.

Conclusion

So finally, in closing, what I would like to convey
to everyone out there is that the ability
of the echocardiographer
to differentiate mitral valve disease will result in more
mitral valve repairs,
and this will result in better outcomes for our patients.
Thank you very much.