Fetal Thoracic Abnormalities - SD

Introduction

My name is David Berg.

I'm from Sunny Scottsdale, Arizona.

I'm at the Fetal and Women's Center of Arizona,

and today I'll be talking about the thorax.

Welcome. I'm speaking about

fetal thoracic abnormalities today.

The topics I'd like to cover are briefly, normal thorax

and lung, and then,

conditions including pulmonary hypoplasia,

briefly, hydrothorax.

I'm gonna spend a lot of time about,

with diaphragmatic hernia,

and then talk about echogenic lung lesions in general,

including cystic adenoid malformation

of the lung and sequestration.

And I'll also be discussing management.

Normal Fetal Thorax and Lungs

We get the opportunity to see the, thorax

and the lung in our normal fetal survey.

Although we're not asked to take specific views

of the lungs, certainly we get many views of the lungs

during our, during our, examination,

particularly when we look at the heart

and we look at the, four chamber view of the heart

or other views of the heart.

We see the lungs as symmetric echogenic structures,

encasing the heart and filling the lungs.

So the lungs are easy to see.

During the course of a normal fetal survey,

we can easily see the echo texture as well as the,

volume of the lungs and ascertain that they appear normal.

We can also look at the vascularity,

although, that is, not as helpful

as simply looking at the, image alone,

but can be helpful in, complications.

We can see the, airway in different ways.

We can see the, trachea, if we look carefully,

and certainly we can also see breathing through the,

mouth and the lips.

This can be helpful, for example, in excluding,

unusual conditions like, choanal atresia.

In that case, we wouldn't get this normal, respiratory

movement, through the lungs

and through the, nasal pharynx as we see here.

We can also look at the lungs if there's any questions

with magnetic resonance imaging,

and certainly that as, become much more,

prominent in the last, decade.

And I'm going to be referring to MRI, in these,

conditions that we're talking about,

because it can be a very helpful compliment to ultrasound.

Imaging the Lungs with MRI

Again, MRI can easily see the lungs.

They show up as,

brighter structures on most imaging,

and, again, encasing the lungs.

And again, we can see the normal, trachea

and airways, as well as the lungs themselves.

And we can also see the, vascularity.

So a lot of information about the lungs and thorax with MRI.

The, major advantage is the superior

contrast resolution of MRI.

And, so it can be quite helpful,

with lung abnormalities.

Normal Development of the Lungs

Looking at, normal development of the lungs, there's,

really three phases of lung development.

The, glandular, the canicular,

and the alveolar phases.

Just want to point out that critical lung development is,

early up to about 26 weeks.

If there is significant hypoplasia, up to

that point, then is likely that the,

hypoplasia will be irreversible.

But, if there is, development of the lungs up to

that point, even if there is hypoplasia

after that, then usually it's not irreversible.

The alveoli actually continue

to develop throughout the pregnancy.

And even, in postnatal life,

Assessing the Thorax and Lungs

We can assess the, lungs

and the thorax in a variety of ways.

The easiest,

besides simply, the subjective evaluation of the lungs

is to, measure the thoracic circumference.

There's very good standards for, normal values

of the thoracic circumference,

and at least in cases, of,

of overall lung volume.

This is a good measure, of the, of the lungs.

It doesn't work, so well and certain conditions.

For example, if there's, marked cardiomegaly

or, other, internal, masses, for example,

hydrothorax,

that wouldn't tell us necessarily about the lungs per se.

But, in the absence of a intrathoracic mass,

the thoracic circumference does give us a, good,

impression and a good values to, to, to be able

to measure lung volumes again.

We can also look at it in, different ways.

And there's, using, 3D volumes, either

with ultrasound or MRI.

We've got, we have good standards

and looking at overall lung volumes with gestational age.

And, not surprisingly these,

and as expected, the lung volumes continue

to grow throughout pregnancy.

Pulmonary Hypoplasia

In terms of complications, I'd first like

to briefly talk about, pulmonary hypoplasia.

Pulmonary hypoplasia, is the,

end result of a variety of conditions.

And when we talk about some of the later conditions, the,

the complications are, usually, as a result

of pulmonary hypoplasia.

Causes of Pulmonary Hypoplasia

Pulmonary hypoplasia may occur from intrathoracic,

mass lesions, such as, diaphragmatic hernia

or, cams, so-called cams,

which are cystic adeno, adenoid malformations of the lung,

or other intrathoracic masses.

Also hydrothorax.

All of these conditions can produce, mass effects,

which compress the lungs

and produce, pulmonary hypoplasia.

Another category, a major category is,

external compression.

This would be from, oligohydramnios.

If there is, longstanding oligohydramnios,

especially early in the pregnancy,

this will result in pulmonary hypoplasia,

which can be irreversible.

Not only is it external compression,

but also it doesn't allow the lungs to fill up with,

with fluid and the normal respiratory movements that we,

that do occur during the pregnancy

and allow the lungs to develop.

Skeletal dysplasia is another category

that can produce pulmonary hypoplasia.

And virtually all of the, lethal skeletal dysplasias,

do result in, lethal pulmonary hypoplasia.

And that is the, reason that,

these conditions will result in, in fetal death.

In those cases, it is, a different setting,

and that is the, skeleton simply doesn't develop.

The thoracic cage doesn't develop normally, and,

therefore it's constrictive,

and does not allow the, lungs

to develop resulting in lethal skeletal dysplasia.

I'm not gonna talk about that particularly in this,

discussion, but that is, typically quite obvious.

Not only is the skeletal dysplasia quite obvious,

but the subjective impression

of pulmonary hypoplasia is usually quite

obvious in those conditions.

And then, there's unusual causes

that may result in primary pulmonary hypoplasia.

Evaluation of Pulmonary Hypoplasia

How do we, evaluate pulmonary hypoplasia?

Well, the easiest is simply a subjective impression by,

looking at the lungs.

Certainly if there's a, mass, we want

to appreciate the mass,

if there's any intrathoracic mass

or, external, compression.

But then there's a variety of,

measurements we can make.

Again, if there's no, intrathoracic mass,

the thoracic circumference is an easy measurement

with good reference standards,

and that would be the one I would recommend for,

for looking at, general, pulmonary hypoplasia.

But there's been a variety of other measurements

that have been used, including lung length, lung diameter,

and more recently lung volumes using 3D ultrasound and MRI.

A variety of ratios have also been used,

and some authorities have also looked at the pulmonary

circulation with, Doppler studies as a measure

of pulmonary hypoplasia.

This is, simply one measure

of pulmonary hypoplasia using a, right lung diameter.

And I just wanted to point out that at, at least in this,

study, the internal measure

of the lung itself was superior

to the thoracic circumference,

and being, being able to, diagnose these,

the conditions of, pulmonary hypoplasia.

So, thoracic circumference works very well when there's

generalized, pulmonary hypoplasia, but,

but with not, not with all conditions.

And we're going to get the most accurate measurements,

and determination of pulmonary hypoplasia

by actually measuring the lung itself.

And again, you can do that in a variety of ways.

This is, one of my attempts

to measure lung volume in a patient with oligohydramnios

and external, pulmonary hypoplasia.

And we can get a, a reasonable estimation

of lung volumes using 3D ultrasound,

and, calculating the volumes.

In general, this will simply,

reinforce our own subjective impression of, of the,

lung, volumes,

but it is a objective measurement that we can compare.

I'd like to, move on to, hydrothorax, but

before I do, I just want to again mention

that pulmonary hypoplasia is the end result of a variety

of conditions we're gonna be talking about today.

And if there's adverse outcome, it's usually

as the result of pulmonary hypoplasia.

So a very important, end product of, of all these,

thoracic conditions we're gonna be talking about.

Hydrothorax

Briefly wanna mention hydrothorax.

There's a variety of etiologies.

It's not, terribly common

as an isolated finding.

Usually it's associated with hydrops.

Usually hydrops is, evident in other areas,

and so it's a fairly easy diagnosis,

but in some cases, it is isolated.

And, the etiology is uncertain.

Certainly some of the,

etiologies we could think about would be infectious.

And we'd want to,

look at things like parvovirus would also want to,

look at, conditions

that may result in hydrops later,

or sort of a pre hydrops condition.

And, look for example, at fetal anemia.

And, and in that case, you'd want to look at the,

middle cerebral arteries, doppler

to make sure there is not fetal anemia.

Would want to, look at chromosomes

because it can be associated with down syndrome

and other, aneuploidies,

and occasionally down syndrome will present

with isolated hydrothorax.

So the typical, workup would include,

amniocentesis, to, evaluate the chromosomes,

middle cerebral artery doppler to exclude fetal anemia.

Obviously, a good look at the fetus

and every other way

to make sure there aren't other abnormalities

with particular emphasis on the heart to exclude,

heart abnormalities.

And in the end result, we'll, we will be left with,

a certain percent of cases, which are, unexplained.

And, and some of these may be the result of,

lymphatic disorders, so-called chylothorax.

But in utero, we don't have chyle, we actually have,

hydrothorax

because the, the, fetus has not eaten yet.

So there isn't really any chyle in that, in that fluid.

Certain conditions then are, are, idiopathic

or associated with this, so-called, chylothorax.

And, I've seen several cases just in this last year,

which did, fairly quickly develop

to hydrops.

So the other thing that we do is we're, we'll certainly,

do a follow up ultrasound fairly quickly within a couple

of weeks to, ensure that this does not develop into,

full blown hydrops.

But, certainly, my experiences last year,

that is not an uncommon, situation.

The, primary,

factor in evaluating the,

the outcome is the presence of hydrops.

If there's no hydrops, there's a,

and no other abnormalities,

and the chromosomes are normal, then the outcome is,

favorable.

If there is hydrops, the outcome is very unfavorable

with, with almost no survivors,

certainly no survivors in this particular, study.

So, that is another, end result of a,

variety of lung lesions.

If it results in hydrops, the outcome is, quite poor.

If there's no hydrops, the outcome is usually favorable.

And that applies also to, to isolated, hydro,

hydrothorax treatment

options for hydrothorax, again,

after the, a very extensive diagnosis are options

to are to observe only.

And I would recommend that certainly initially, again,

I would do a short term follow up,

recommend a short term follow up in,

two

or three weeks, or maybe even in one week,

but a, a short term follow up,

thoracentesis can be performed,

but there isn't any, great reason to do that early.

I, it's, it's common

to perform a thoracentesis shortly

before delivery to, help the lungs expand

and help the neonatologist right at the point of delivery.

But because of fluid will reaccumulate very quickly.

Thoracentesis is a, a short term, option,

and is, is not a cure.

Certainly, you can put in indwelling, shunts.

And, and here's an example of one where a shunt was placed,

and at the time of, delivery, a,

another shunt was placed.

But you can see actually where the,

where the shunt was placed in the side of the,

the fetus.

And this, this can be performed in utero with drainage

of chronic, isolated hydrothorax.

It's not performed, very frequently,

but certainly, it can be performed.

Sometimes these fluid collections will continue to,

accumulate and continue to come back.

And then we have to look for other treatments,

following delivery.

And lemme go back to that one.

Just to mention one item,

and that is the, possibility of using sclerosis agents.

This has also been, attempted

or performed in select cases, prenatally,

but, more commonly as, postnatal.

Congenital Diaphragmatic Hernia

I like to go on and talk about the, and,

and focus on, diaphragmatic hernia.

Diaphragmatic hernia is, is,

not an uncommon condition that we will see.

Any major center will see, a number of cases

during the course of a year.

The, the condition itself is,

is quite easy to explain.

It simply represents a failure of fusion of the diaphragm,

usually the left sided diaphragm,

which produces a hole

that separates the thorax from the abdomen.

And now we no longer, have,

an enclosed thoracic cavity.

This allows, the abdominal contents

to come up from the abdomen into the thorax,

and, compress the, the lung

and thoracic structures producing a pulmonary hypoplasia.

So the, the defect itself is, relatively easy.

It's, can be fixed surgically after birth,

and that's not a problem.

But the, real problem is the development

of pulmonary hypoplasia during, pregnancy, which,

which, can be fatal.

Diagnosis of Diaphragmatic Hernia

The diagnosis of diaphragmatic hernia is,

usually not difficult, but sometimes it can be.

And what we look for on the,

we've got several clues when we look at, views

of the abdominal circumference.

First of all, we, what we fail to see is a normal,

fluid-filled stomach,

and that is usually the first clue.

Now, there are occasional cases

where you will see a fluid-filled stomach,

and there still is a diaphragmatic hernia,

but most cases do include the, the stomach as well.

So that is a, a primary clue.

The, abdominal circumference may be, small,

as you see here, is so-called a scaphoid abdomen,

because the abdominal contents have herniated

into the thoracic cavity.

Other, direct clues are looking at thorax itself,

and of course, usually it's a left sided diaphragmatic

hernia, so it's gonna result in a, mass effect.

On the left side, typically the stomach's involved.

So we can see a fluid-filled stomach with compression

of the heart and the mediastinum to the contralateral side.

And again, usually that is towards the right side.

And with large diaphragmatic hernias,

the heart is compressed, right the way to the,

right thoracic, wall after delivery.

What we'll see is abdominal, contents in the,

left chest, the stomach, and,

and other abdominal contents,

as we see in this radiograph here.

So, diaphragmatic hernia is,

relatively straightforward in terms of the actual condition,

and in most cases of diagnosis,

but some cases can be, difficult to diagnose.

Fortunately, the cases that we are, that we might miss,

we're likely to miss, tend to be associated with a,

a much better outcome.

So the ones that we're going

to see are the ones associated with a, worse outcome.

The ones that we might miss

or potentially could miss,

are associated typically with a good outcome.

This is a view of a, abdominal,

circumference in the third trimester.

And, unless you are observant, it would be easy

to miss the fact there that there isn't a,

fluid-filled stomach in this case.

And certainly I've seen, a number of,

diaphragmatic hernias that were, missed,

by, outside scans.

For example, in,

conditions like unexplained polyhydramnios,

certainly you want to think about diaphragmatic hernia.

Certainly if there's a, any kind of,

heart displacement

or, abnormal heart, position you want

to consider diaphragmatic hernia.

So you have to have a high index of suspicion.

One way I like to look at it is in coronal

or longitudinal views.

In addition, of course, to axial views,

not only are we looking at the, thorax,

but also I like to look at the diaphragm itself.

And if you look here,

you'll see the normal diaphragm over here.

But as we come to the other side, in fact, we'll see,

you can see the, And now we've,

now we're on thoracic, now we're on a, axial view,

and you'll see that fluid-filled stomach.

And we can see this in a, in a, in a variety of ways.

Lemme go back to this, axial view.

See the normal diaphragm here,

but here we we're gonna lose it.

Here's a fluid filled stomach,

and we'll notice that it goes right

through a defect right here through the,

diaphragmatic defect.

And, and I think that we can, we can ascertain the size

of the diaphragmatic, hernia, actually very well in a,

in a direct way, rather than simply estimating it by,

looking at the, degree of intrathoracic content.

So think about looking at the diaphragm itself.

I think there's a lot of information be gained there.

Diaphragmatic hernia can be missed or misdiagnosed.

And this case actually, was,

thought to represent there.

You could see a, a heart displacement that was obvious,

but there was interpreted as an echogenic lung mass.

So, initially, misdiagnosed as a CAM,

and not a diaphragmatic hernia.

And it's very important to make this distinction.

Diaphragmatic hernia, especially large ones like this,

are not associated with a good prognosis,

where cams have a, a very good prognosis.

So we wanna look very carefully, again,

look at the diaphragm itself on a coronal

or longitudinal views, but there's other clues here.

And that includes a, a little bit of fluid.

Now, you certainly can get cams with cystic lesions,

but if you just stop and watch, you'll usually be able

to see peristalsis.

And sometimes we're so busy scanning, we forget

to just stop and watch.

If you just stop and observe,

you'll usually see a little bit

of peristalsis in this bowel,

which is herniated up into the thorax.

So, very important not to miss or misdiagnose.

If there's any question, certainly we can get an MRI.

And here is a, longitudinal view of an MRI showing the,

intestines herniated up into the,

thorax.

This is that same case, I just, showed a bit later,

and, confirming that in fact,

it represents a diaphragmatic hernia, not a, C cam.

Associated Anomalies in Diaphragmatic Hernia

Let's, the, the three things really, what, what we can,

what can we do with ultrasound when we, are suspecting

to diaphragmatic hernia?

First of all, we wanna detect it.

Second of all, we want to look for associated anomalies.

And the third thing we want to do is, characterize it.

And by, characterizing it, we want

to look at those factors that are associated

with a worse prognosis.

But, the, but the, so first is detection.

Second is looking at associated anomalies,

making sure it's isolated,

and that's very important with diaphragmatic hernia.

Here's one case where, we were able to, easily tell

that there was a large, omphalocele that wasn't a problem,

but we actually missed the fact

that there was an associated, diaphragmatic hernia.

And both of those conditions can produce,

pulmonary hypoplasia.

And in this case, it was, a lethal pulmonary hypoplasia.

This is part of the pentalogy of Cantrell.

Some of these omphaloceles can be a smaller

and could potentially be missed, so certainly look for that.

But what we wanna do is take a good look at the,

entire fetus

and make sure there aren't any other

associated abnormalities.

Certainly the presence of associated abnormalities is a,

a key factor in evaluating the prognosis, just as it is with

any kind of a birth defect that we may see.

Before birth.

In this study,

there was a hundred percent mortality when there were

associated abnormalities,

and the associated abnormalities were

present in a third of cases.

And those, diaphragmatic hernias, which were isolated,

the prognosis was much better.

And we'll, we'll get to the factors that can be associated

with a, with a better prognosis.

Looking at associated abnormalities,

chromosome abnormalities are reported in

between five and 15%.

So, it is important to confirm that,

chromosomes are normal.

As we go forward

and looking at the, conditions

that can be associated with anomalies,

you can see a variety of, syndromes here.

And, usually these will be associated with,

other conditions we can see by ultrasound.

So, again, the, one of the key points is

to take a good look at the fetus

and make sure there aren't any other, abnormalities.

Prognostic Factors in Diaphragmatic Hernia

Our third role, and,

and especially at referral centers, is to characterize the,

the defect itself and,

and be able to, separate those,

diaphragmatic hernias associated

with a good prognosis from those associated

with a poor prognosis.

And a variety of factors have been looked at,

and we'll get to that.

But one of the, one of the factors that, has,

prevailed as an important factor is the presence

of liver in the thorax.

Whether the liver is up in the thorax

or the liver remains down

where it belongs in the abdominal cavity.

And, this is a, a summary of some older literature,

but certainly you can see,

big differences in survival rates

or the need for, ecmo,

which is a very vigorous, respiratory support

and would like to avoid ECMO if, if at all possible.

But, much higher chance of ECMO when the liver is up.

Also, a much higher chance

of requiring a surgical patch,

when the, liver is up.

And that's simply because the, defect tends to be bigger

than when the,

when the liver remains down in the, in the thorax.

So, big differences,

whether the liver is up in the thorax,

where the liver is down in the abdominal cavity,

and that's one of the things that we want to, determine.

And one of the ways we can do that, of course, we can,

look at the, with, simply with, 2D,

but we can also look with, color flow and,

and duplex doppler,

and looking at the, and,

and portal vessels can be very helpful, particularly

as you follow the portal vessels,

up from the umbilical vein,

and they extend up into the thorax.

Well, that's the, clue that we have a portion

of the liver up in the, up in the thoracic cavity.

So, looking at the, vascularity can be very helpful

for determining that.

If there's any doubt,

and certainly I think nowadays,

most people would also get a MRI,

and I would encourage that to also determine whether it's,

there's liver, up in the thorax or not.

But I think, the MRI has made us much better in terms

of, using ultrasound alone.

And so there's very good agreement now, I think,

at least in, referral centers, between ultrasound

and MRI, and,

determining whether the liver is up in the thorax

or not, in this case, using the MRI, there's a portion

of the liver, up, as you can see in this coronal image,

next to the, next to the fluid filled stomach.

One of the clues of looking at, liver involvement,

in the thorax, actually, you can,

you can also use on, transverse views, as in this case,

in a, in a key feature,

or a good clue that actually was, suggested to me

and probably to some of you, in prior lectures

by Ruth Goldstein, was the, position of the stomach.

If there's no liver involved,

then oftentimes the stomach is anterior, right up next

to the anterior chest wall.

But when there is liver involvement, the liver tends

to be anterior and pushes the stomach posteriorly

as it is in this case.

So here, there's liver involvement pushing the stomach

posteriorly, and that's a very helpful clue

to looking at liver involvement with diaphragmatic hernia.

And corresponding, MRI, again,

confirming liver involvement.

One of the things that's very important, to,

to do when we characterize thoracic,

problems when we characterize diaphragmatic hernia is

evaluation of lung size.

As I mentioned before, with diaphragmatic hernia,

it can be, more difficult

because we've got this, large amount of, of mass,

sometimes quite big,

and it can be quite hard to distinguish the,

intestines from the, from the, lung itself.

So, some of the ways of trying to, to,

to look at it, it can be quite difficult.

And a variety of ways have been, attempted.

Not surprisingly,

the thoracic circumference itself doesn't work very well.

The, the one method that is, has been suggested is,

seems to be standing the test of time,

while there's really two methods.

One is, looking at lung volumes,

and, that's a little harder with the ultrasound,

as we, as we're looking at, in this case, it can be done,

with ultrasound, but, it's easier with MRI

because of the superior contrast

resolution as we see in this case.

Certainly you can do 3D lung volumes using MRI.

And there's very good correlation between 3D

estimation of volume using 3D ultrasound with estimation

of volume by MRI.

So that is certainly one way to, look at lung volumes,

and probably the most accurate.

But the method that has been adopted, I think

by virtually everybody now, has,

been using this right lung to head circumference ratio,

or so-called LHR, right lung

to head circumference ratio.

This turns out to be a, a very helpful,

and it correlates very well with lung volume.

So it, simplifies the method.

It's something that we can, easily do,

as we're performing ultrasound.

And this is how you do it, in a, thoracic, in a,

in a transverse view of the,

that includes the heart.

What we're looking for is the, size

of the contralateral lung.

And we're looking, what we do is we measure it,

and the, two diameters, in millimeters,

and multiply that

and divide by the,

head circumference ratio also in millimeters,

that turns out it's very helpful

and a very good, correlate of lung volume.

And now we're looking at, the, contralateral,

lung volume,

because the, the side of the defect,

typically the left side,

we really don't see the, lung at all.

It gets completely obliterated.

And what we, simply try

to do is look at the contralateral lung volume,

which is typically, again, the right side.

And this is a,

even though it seems like it's fairly simplistic

and it's, it's only on a single plane,

it actually correlates very well, not only

with lung volumes, but also most importantly with outcomes.

I'm gonna refer to a couple studies,

but they're all, have similar conclusions,

and that is the lower the lung

to head circumference ratio, the poor survival rate.

And some people have shown a cutoff using, one,

and others have used, a, a lower cutoff of 0.6.

But in this particular study, using, certainly,

certainly these lower values, like 0.6

or below, the survival rate is very poor.

And, and I think in most studies,

survival rate is either zero

or close to zero when the lung volumes are that small.

In comparison, when we have a lung

to head circumference ratio of 1.4

or greater survival rate is, is very good.

Something maybe approaching 90% in this particular

study, was, was a hundred percent.

But, it's really very important to, to distinguish,

because what we want to do is be able

to counsel these patients appropriately,

and it makes sense to, give as specific information

as possible to try to compare apples to apples

and not apples to oranges.

So, we want to get as much information as we can.

And fortunately now, we do have a lot of information

about, about outcomes.

I'm gonna get to that in just a moment.

This is important,

and that is, there's a good correlation again between,

lung to head circumference ratio

and lung volumes using MRI.

So we certainly can use MRI,

but the lung to circumference ratio with ultrasound alone,

in fact, is very, predictive.

Just, this, this is a valuable tool, again,

to help separate those out with good prognosis from those

with poor prognosis.

And again, here's a,

a study from the San Francisco group, which is the one

that came up, which is a group that came up

with the lung to head circumference ratio.

And here they were able to identify, excellent survival

for those with, without a liver,

without liver involvement,

and with a lung to head circum ratio of greater than,

well, essentially 1.4.

And in that particular series,

there was a hundred percent survival rate.

So, very important, at least in terms of,

counseling and be able to, to select those patients

that have a good prognosis.

I think, this is a, an even better study

that just came out last year.

And I want to go to over this a little bit in detail,

because it certainly provides us

with the most detailed information we've had

to date about neonatal outcomes using, lung

to head circumference ratio.

And, so very important.

And, and here's the long to head circumference ratios up

above here, less than one, intermediate,

ranges between 1.0 1.0.4 and greater than 1.4.

Now, actually, this study looked at observed

to expected lung to head circumference ratios,

not absolute numbers,

but, it corresponds, roughly,

with these, with these values.

It turns out the lung to head circumference ratio does

increase slightly with gestational age,

but in the age range that we're looking at,

these numbers actually work, quite well.

So you can use, these absolute numbers as well.

Just going through the, various outcomes,

the most important one, of course, is survival rate.

And again, a major difference.

Less than one, survival rate is only 18% compared

to almost 90% when the lung has scrum ratio is greater than

1.4, assisted days of ventilation.

Again, major differences 38 days versus nine days.

And again, and,

and using, looking at, other outcomes like,

the need for a surgical patch repair of the hernia,

because the hernia defect itself is so large,

75% versus 9%.

Again, huge differences simply by using this,

simple method of looking at lung to head circum ratio,

other long term outcomes that are important.

Gastroesophageal reflux is a,

is a major problem among survivors.

And, and again, this correlates very well

with the size of the defect,

and, the need for ventilatory support,

during that period of time.

So, less than one, 90% roughly have,

GE reflux, whereas when it's, ratio is greater than 1.4,

only 10%, again, big differences between, ages

to full feeding, full, oral feeding,

51 days versus 19 days,

or total days in the hospital, 73 days, 30 versus 31 days.

So, huge differences between those with,

smaller lung volumes as reflected by these smaller lung

to h c ratios compared to those that have a,

smaller defect and therefore, larger lungs

and less pulmonary hypoplasia.

Long-term prognosis is also important to look at.

Survivors

with diaphragmatic hernia can result in chronic lung

disease, and that's much more common in those

that required ECMO versus those that did not,

we're also, learning about, or,

or know about, other long-term outcomes including,

developmental delays

and, neurologic injury, cerebral palsy,

and neurologic, developmental delays in 22% versus 6%,

and those requiring ecmo

and those that did not require ecmo.

And looking at those that required a surgical patch,

GE reflux, which it can be, quite debilitating,

in,

79% versus 11% for those that did not require a patch.

And finally, looking at,

just looking at the need for ecmo, in another study,

a hundred percent of those with a lung, h c ratio

of less than one versus 33% for those greater than 1.4.

That's a, a different study than the one I just referred to.

But again, coming up with the same conclusions,

the prognosis is much worse for those

with large diaphragmatic hernias, which are associated

with small lung to head occurrence ratios.

And the prognosis is much, much better for those

with smaller defects associated with, larger lung

to head circumference ratios.

Also, having the, liver in the thorax,

intrathoracic liver produces smaller lungs in general.

And so that is also an independent risk factor for,

for, looking at, lung volumes and outcomes.

Particularly in, in this study, I just referred to the,

need for a patch.

A surgical patch was also associated

with intrathoracic liver involvement.

Management of Diaphragmatic Hernia

In terms of, therapeutic options management,

a variety of things have been, tried

and we've had actually very,

good success in postnatal outcome,

improvements in respiratory therapy

and particularly, certainly,

there there's a variety of options there.

We can use ECMO if needed, which takes the, total,

support away from the fetus

and makes an external support for the lungs and the heart.

But that should be a temporary measure only,

and we try to avoid that whenever possible.

As I've already pointed out, there are long-term outcomes

as, poor outcomes associated with the use of ecmo,

which can include neurologic,

developmental delays as, as well.

So we certainly try to avoid ECMO whenever possible.

High frequency oscillation, is, is, is needed.

And, there's, also a,

in, in recent, more recent years, using low pressure,

atraumatic ventilation, high frequency,

low pressure ventilation can be, very helpful.

What we try to do is, minimize the trauma to the lungs

because there will be sequelae to that if there is,

if there is trauma to lungs.

In terms of prenatal treatment,

really our options are quite limited.

We've had a, a, a, a large body of literature,

which is looked at various options, in terms

of prenatal surgical management,

but, all of those have really have fallen

by the wayside, in large part

because of the, improvement we've made in the,

postnatal management.

So there's been less need for more aggressive,

prenatal, surgical options

and prenatal surgery really has gone by the wayside.

The only thing that has continued is, using a,

catheter, which I'll get

to a balloon occlusion catheter,

which can be used in the worst cases, to,

try to improve the outcome.

But other kinds of,

prenatal surgery really have gone by the wayside.

And the best thing we can do, prenatally, is to,

characterize those, those, fetuses

with diaphragmatic hernia to be able to,

ascertain which have the good prognosis,

which have the worst prognosis,

and get that information to the parents

and to the, the people who will be looking

after the baby after birth.

And that can be very helpful.

In terms of, the prenatal, management that is still

possible, is a,

a tracheal occlusion via detachable balloon.

Again, there's been a variety of methods that have,

been proposed and have gone by the wayside,

but there's still an ongoing trial using this method,

and there has been, some data that has suggested that

that can be useful, particularly for those,

fetuses associated with a worse prognosis.

That is with a, a small lung to head circumference ratio,

and with liver involvement as well,

in this, procedure, what happened?

The idea is simply to occlude the trachea,

and that allows the lungs to, expand with fluid

as it naturally would.

For example, in cases of laryngeal

or tracheal, atresia, the lungs will fill up with fluid

and to try to counterbalance the development

of pulmonary hypoplasia.

So as it is performed today, this,

if it is performed, it'll be done typically around 26

to 29 weeks, and it will,

and it will be done, simply, it won't require a,

hysterectomy, but we can do it percutaneously

with ultrasound guidance.

The, balloon is typically removed prior to delivery.

So it's, it's a temporary measure

to simply expand the lungs.

And again, there's some, some data

to suggest this can be helpful in the

worst prognostic groups.

Here's, some of the original data from,

now over, 10 years ago,

and looking at the worst prognosis, groups that is

with a low lung to head circumference ratio

and liver involvement.

And, they found, improved,

survival rates using the, the tracheal occlusion method,

particularly using this, this,

the method I just described.

So, again, there's ongoing trials at,

several centers in the United States.

And if you have a patient with a very poor prognosis,

certainly I would encourage you to, to call them,

chop Hospital, children's Hospital

of Pennsylvania is one, uc, San Francisco is another.

And you can call and see if your particular patient

might, fulfill that criteria.

And again, that's only for the worst prognostic group.

Echogenic Lung Lesions

I'd like to go on and, finish, most of the rest

of the talk, talking about echogenic lung lesions,

and I'm really grouping of,

several different conditions when I talk about echogenic

lung lesions, acknowledging the fact

that it can be quite difficult

to distinguish some of these conditions.

The most common one we would consider here

or think about would be cystic adeno, adenoid,

malformation of the lung.

I'm gonna refer to it as CCAM, just

because it's a lot easier to say, sequestration,

which is, similar but different.

And there's actually overlap with CCAM, both by,

by imaging and pathologically.

And there's also other conditions

that can produce echogenic lung lesions, including,

airway obstruction, really any, any cause of obstruction.

And, and here's one case's, an older case

from the literature,

but it's interesting, that, that there's a,

a very large echogenic mass, filling the,

the, left side of the thorax here,

producing cardiac displacement.

It could easily be, diagnosed as a C cam,

but in fact, the underlying condition in this case was,

tracheal, obstruction

or, stenosis, really by a bronchogenic cyst.

So it points out the fact that any cause of,

obstruction can produce, what

what happens is the lungs fill up with fluid,

they become expanded.

We see, multiple interfaces

because of the fluid filling the alveoli, and they show up.

These multiple interfaces show up as echogenic lesions,

with mass effect.

Kind of a classic one, condition is, this,

where we've got markedly expanded lungs on both sides.

So the heart's actually compressed in the middle,

and we, and we see the, really, the, the thorax seems to be,

completely filled with, with the lung tissue.

There isn't any other mass effect per

se, and it's very symmetric.

This is a, a very diagnostic condition.

When we see it. It's one of two conditions.

It's either tracheal atresia

or laryngeal atresia or combined.

You can talk about it as high airway obstruction.

And, that's a very typical, condition,

unless it's quite, quite high at the laryngeal level.

They're, associated with the poor prognosis.

If there's, if they're at the level of the larynx,

it's possible to, to, to actually,

catch those at the time of delivery,

do a tracheostomy and, and avoid the, obstruction.

But, that's only been

performed in a handful of cases.

Here's another echogenic lung lesion, filling the,

one side of the thorax here, in this case, the left side

with contralateral, displacement of the heart.

This is a older case, but typical of A CCAM.

Here's one that's, echogenic

with cystic areas within it.

And, the most common in my experience is simply echogenic

or with echogenic, with, one or two,

or, or small cyst,

but sometimes they can be, mostly cystic,

and,

and so-called macrocystic lesions.

So they vary. The, typical echogenic,

ones actually have a very good, prognosis.

We can also see these with MRI.

These, seem to correspond to, to,

low bar involvement.

And we can, we can, characterize where they are,

how much of the lung they involved,

and confirm that in fact, it is a, c cam

and not a diaphragmatic hernia notice.

In this case, looking at the MRI,

we can clearly see the diaphragm

and separation from the, from the stomach

below the diaphragm.

So, MRI, again, can be very helpful.

One thing we do, when we look at,

lung lesions is also look at the vascularity,

in an attempt to distinguish c cams from sequestration.

Sequestration typically have a,

arterial supply from the aorta, a systemic arterial supply,

and we can oftentimes see that by ultrasound.

It can also be seen at the time of, surgery,

another case of sequestration,

with a arterial systemic supply.

But in fact, there's, overlap between c cam

and sequestration, both by imaging and pathologically.

So it's not so important to,

to absolutely make this distinction.

Here's another case of a very, good example

of arterial supply with the sequestration.

And again, we can look with MRI

and we can see, systemic vessels sometimes

with MRI itself,

but usually that's performed better with,

with ultrasound and, and doppler imaging.

Here's a one that had, combined pathologic features

of both the CAM and a sequestration.

Again, a very typical looking lesion

with a echogenic lung mass, in this case,

just a small cystic area with marked, displacement

of the heart, and the, mediastinum.

By the way, in the older literature, if we,

if we looked at these kinds of lesions, we would've said,

gee, this looks really bad.

There's, marked displacement of the heart.

This has gotta be associated with the poor prognosis.

And in fact, the older literature suggested it was,

but the natural history is such

that these actually have a very good prognosis

that these lesions will look like.

They disappear. They look like they resolve, and,

and the heart and the mediastinum will return

to their normal position in the vast majority of cases,

particularly these echogenic, masses.

So, we give a uniformly favorable prognosis when we see these.

Here's another, here's one example

where we've got an echogenic lung mass at 22 weeks at birth.

It looked completely normal.

And I guess the question is, was that a, C cam

or was it a, transient obstruction,

a bronchial obstruction?

Unless that, fetus,

unless that neonate has, surgery, we,

we won't really, we may not know.

No, here's another one with a, a large lesion.

It can look, quite impressive, but this is a CAM.

And in fact, on follow up, it actually looked,

very good.

It was, it was became harder and harder to see here.

You can see on a follow up, the heart returned almost

to normal position.

And, the lesion itself was now becoming very difficult

to distinguish from the adjacent lung.

So, and that's a, a typical scenario.

So the C cams

and these echogenic lung lesions are much easier

to see in the second trimester than they are

in the third trimester.

And, and the typical, natural outcome is in fact

that they will resolve and be,

may become impossible to see.

Here's another one. A large echogenic lesion, mass

and on follow up was, became virtually impossible to see.

So if we had seen this patient only in the third trimester,

we would not have known that there was

a lung lesion present.

Once again, you can, characterize these by,

by measurements and lung volumes.

But, that's not as important here

because regardless of their size, they're associated

with a good prognosis, at least if they don't,

if they don't have, hydrops, now,

when they look like they resolved, do they actually resolve?

We did a study when I was in Seattle looking at,

10 patients, with, what looked like C cams.

Four looked like they resolved completely

after 32 weeks.

Three looked like they almost resolved,

but there was just subtle alterations and echo texture.

In fact, we would've, not,

we would've easily missed them if we had only scanned

them in the third trimester.

And they can look, normal

or near normal on, postnatal X-rays,

but all of them had an abnormal CT scan,

as we see in this case.

So there is a, a, a a, a, a mass

that does persist.

It's just that it, it looks like it resolves both

by ultrasound, and it can look relatively normal

on a chest radiograph.

So our protocol is to get a CT scan after delivery.

Now, the real question is what to do with the, with the,

with those lesions.

I'll get to that in a moment, but one question is,

why do they look like they resolve?

And there could be different reasons.

The fetus certainly grows while the mass size may be,

is quite stable.

Also, maybe there's a relief of the obstruction,

which could occur of the, trachea or bronchi.

And, and,

and, so there may be different reasons why that the,

the, the mass effect actually, it looks,

looks like it resolves.

But I think what happens is probably the,

the mass itself remains stable

and the lungs are able to develop,

and grow around it, so it becomes less prominent and,

and, less echogenic.

Prognosis and Management of Echogenic Lung Lesions

The, prognosis for CCAMs

and sequestration these echogenic lesions is again,

excellent, when there's not hydrops,

and that's really the key.

If there's hydrops,

the prognosis is poor in this series,

and,

but if there's no hydrops, then,

a hundred percent survival rate.

So, again, excellent prognosis without,

without hydrops.

The other thing about c cams

and, sequestration these echogenic lesions is they're

almost always isolated.

They, almost, never have associated abnormalities.

So overall, even though they can look quite worrisome early

on in the second trimester,

they really have an excellent prognosis.

And the key is, of course,

to distinguish them from other conditions

like diaphragmatic hernia.

What a couple conclusions,

these echogenic lesions are,

are certainly more common than generally recognized.

And in fact, if we don't, look in the second trimester,

we may miss them entirely.

And since the, patient may be asymptomatic at birth,

if we weren't, if the patient wasn't scanned at the right

time, they would go completely unrecognized.

Even though when they look like they're resolved

by ultrasound and they're asymptomatic, it does not,

mean that the lesion is gone and it may persist.

Now, typically, what's the natural history of these is they,

is actually hard to know,

but they can develop, recurrent infections later,

in infancy.

And, and there's also a, a small chance of development of,

at least authorities think there's a small chance

of development of a rare kind of tumor

of pleuropulmonary blastoma later in life.

So these are the reasons why, if,

if resection is performed in a asymptomatic patient,

why they would recommend surgery.

But, certainly this is a, area of controversy

and deserves some further study.

What is the optimal management for these lesions,

particularly in patients who are asymptomatic?

In our, own experience in San Francisco,

when we tried observing alone, the surgeons started to see

so many of those, they started observing alone.

But oftentimes they did develop respiratory,

infections later in the first year of life.

And so they, changed their approach to,

to perform prophylactic surgery.

Another option that's been suggested

and has performed has been arterial embolization

of these lesions, which would avoid the need for surgery.

And in this study, 16 patients went arterial,

embolization, and it looked very successful,

in all patients except, one and two other patients.

It was partially successful.

Intraabdominal Pulmonary Sequestration

The very last condition I wanna mention,

before I conclude here, is something that, here,

I'm looking at the abdomen, but it is related to the thorax.

And that is these, echogenic lesions, masses,

which are, in the left upper, quadrant,

behind the stomach.

And they're really a, a very diagnostic, when you see them.

Here's an echogenic mass,

and this represents a extra lobar intraabdominal

pulmonary sequestration.

Very typical. Now, some people can get worried

and think, what about a neuroblastoma?

But I, I've not found it difficult to, distinguish

that between a neuroblastoma,

sequestrations are always on the left side,

these intraabdominal sequestrations.

They're homogeneously, echogenic,

they're seen in the second trimester, and or beyond.

And they're relatively common.

Neuroblastomas may be seen both in the right and left side.

They're usually of mixed echogenicity.

They're not homogeneous, because they're tumors.

They're only seen in the third trimester.

They're not seen in the second trimester,

and they're relatively rare.

So, just to keep an eye out for these conditions.

'cause when you see them, it's a, it's quite diagnostic.

Conclusion

What I'd like to conclude here, thank you

for your patience, and, conclude by saying

that prenatal imaging, which includes both ultrasound

and MRI, has broadened our knowledge

of congenital lung abnormalities

and also their natural history.

I believe that's improved, our, ability to,

to select patients and be able to counsel patients.

And, and that's been very helpful

because there's been tremendous,

improvement in postnatal therapy.

For conditions,

especially things like diaphragmatic hernia.

The prognosis remains, poor for those,

diaphragmatic hernias

with large defects in small lung volumes.

And, we really don't have a lot to offer except

for this experimental, procedure,

which I described in those with a worse prognosis.

Prenatal diagnosis is essential for, first of all,

determining the correct diagnosis

and then help guiding counseling and, and management.

Thank you very much for your attention.