Non-Obstetric USD Guided Interventions - HD

Introduction

Hi.
I am Dr. Nathan Sobel from Mumbai, India,
and today I'll be talking on ultrasound interventions
in non-op practice.
This lecture is basically meant for people
who are just about to start doing interventions
or for postgraduate students
and I hope it's going to be useful to you.
Thank you.

Choosing an Imaging Modality for Intervention

Now, when we choose an imaging modality
for intervention, it all depends upon the lesion itself.
Its location, size, relative visibility,
availability of imaging modality,
and the personal experience.
But by far
and large, any lesion that is well visualized on a sonogram
is optimal to ultrasound guided intervention.

Strengths of Ultrasound

Ultrasound has several strengths.
It's the only real time technology and therefore it is safe.
It's got speed because you're seeing things real time.
As soon as the needle comes out, one can compress the site
of puncture and if there are any complications they can be
picked up very easily.
Here, for example, we are aspirating a breast cyst and
before the patient knows about it, the fluid is out.
Real time is the biggest advantage
of ultrasound in interventions
and here you can see
that we are doing an FNA from a lymph node,
which is very close to the carotid and the jugular vein.
But since we are able to see the tip of the needle through
and through during the procedure, we can be sure
that it does not touch the carotid artery or the jugular vein.

Real-Time Technology in Practice

This is another example
where real time technology comes into play.
This child has an adenoma very close to the pericardium
and as you can see,
the needle is entering into the pleural cavity.
But because of the real time technology, we can be sure
that the needle is not touching the pericardium
or any unwanted area.
Besides this ultrasound has several strengths.
One can guide in multiple planes.
One can switch on color Doppler
and have a look at the vessels around it's readily available
and one can do procedures as
with a portable machine in the ICU as well.

Types of Interventions

So there are two types of interventions.
Diagnostic, which includes FNAC and core biopsy
and therapeutic, which are mainly drainage procedures,
ablations, radiotherapy, et cetera.
We will just go through some
of those which are done routinely.

Procedure Room and Pre-Procedure Preparation

Now it's very important
that we do the procedures in a proper procedure room,
which has got basic facilities
with all the needed instruments
and basic patient monitoring devices, as well
as basic resuscitation equipment as well.
Pre procedure it is very important to take consents
as per the requirements of each country.
It is also important to look for altered coagulation,
especially if you're doing a core biopsy
of a vascular organ like a kidney or the liver profiling.
Antibiotics may be given, especially in a prostate biopsy.
Pre medications usually are not required,
but it is better to keep an IV line
and keep atropine full set
or glycopyrrolate ready at hand,
especially when you're doing a pleural tap.
Okay, Looking out
for coagulation disorders also depends upon the
standard of care in your own setup.
So we have various guidelines which have come from
various institutes.
One can adapt a guideline for you.
For example, we have guidelines from the University
of Wisconsin, which are good,
but as I said that each place can have its own guidelines,
but when we are doing a core biopsy of an organ like liver
or kidney, it is better to take for coagulation disorder.
Similarly, stopping anticoagulants like aspirin, clopidogrel,
et cetera, would largely depend upon the institute
where you practice and the guidelines which are
available at your place.

Aseptic Precautions

It's very important to take complete aseptic precautions,
clean the probe properly as per the guidelines
of your manufacturer.
All the accessories like the guides, guns, et cetera,
have also to be properly sterilized
as per the requirements of the manufacturer.
Even when we prepare the patient, it is better
to prepare the patient with proper.
I clean the patient properly with iodine or Betadine
and also drape the part so
that we do not touch any area which is unsterile.

Types of Ultrasound Guided Procedures

There are two types of ultrasound guided procedures.
One is a free hand approach
where the needle is free in our hand.
This allows greater flexibility
and also allows subtle adjustment.
When we do the procedure, we also have guides
and typically guides are used for transvaginal
or transrectal probes.
Guides can also be used when you are negotiating
through a very small area.
Here, for example, in the abdomen, the window is very small.
So if I don't want to make any mistake,
I can use a guide on my probe.

Needle Visualization Challenges and Tips

When we start doing procedures, one
of the most common problems which people encounter
is the non-visualization of the needle tip
and the commonest reason why the needle tip is not
visualized is
because of improper alignment of the needle tip
and the transducer.
So we have to remember
that the needle under the central ultrasound beam must
be in the same plane.
The lesion and the needle should be in the same plane
for visualization of the needle in the lesion.
As we can see in this figure, there are two types
of approaches in plane and out of plane.

In-Plane Approach

When we do an in plane approach, the needle goes
within the beam from a distance away from the probe.
So that's the needle being placed
and as we insert the needle,
it'll go within the beam of the ultrasound.
If you want to see
how the needle goes when you do an in plane,
we can put a needle in attachment of the probe
for biopsy and then just push the needle.
As we can see, the needle is going now within the plane
of the ultrasound, when we do an in plane approach,
the needle is visualized during its entire path.
Of course, we have to travel a larger tissue,
but this is an easier technique for someone who is new.

Out-of-Plane Approach

We have out of plane where we place the needle adjacent
to the probe and then insert the needle.
In this procedure, the needle is not visualized along
its entire length.
Of course, a less tissue is gone through here.
For example, we are doing an FNA out of plane
and here we are doing a pleural tap out of plane.
Sometimes when the area where you're working is very small,
we might have to go out of plane.
So here we have two examples
of an FNA being done on lymph nodes.
This is an in plane example where we can see the needle
through and through, and this is out of plane
where we can see only the tip of the needle.
It's very important to see the needle through
and through right from the point you enter the skin till
you reach your target.
And there are several tips which can be useful
to improve needle visualization.
First of all, that should be a proper position
of needle insertion.
The needle should be parallel to the long axis
of the transducer and should not be out of axis.
One should work with shallow angles of the needle
and rotation of the bevel towards the transducer
and smooth motions can also improve needle visualization.
Here is an example where we take advantage
of the air in the bevel to look at the tip of the needle.
We can also improve the needle visualization
by doing a jiggling movement.
As we go through, we can improve the reflectivity
of the needle by special codes.
We can use chrome on the on your ultrasound machine
or we can also use color Doppler where we can see the tip
of the needle as a colored artifact.
Here's an example of an echogenic needle.
This needle is visualized better,
but these are costly needles
and we don't use them in day-to-day practice.
Here's an example. If everything goes fine
and your technique is fine, you can see the needle through
and through after you have entered the skin,
till you reach your target.

Fine Needle Aspiration (FNA)

Let's talk about FNAs, which are most commonly done.
We have a choice of needle starting from 18 gauge
to 24 gauge.
These needles could be small
or they could be large in length as for example, yeah,
we have spinal needles which are longer in length.
It all depends upon the depth at which you're working
for an FNA.
The finer the needle, the better is the yield
for the cytologist.
So one should use as fine needles as possible.
This is very important.
So there are two types of FNA techniques.
One is a capillary filling
and the second is with the use of a syringe
where we apply a slow suction.
Capillary filling is typically used
when you have a very vascular organ like for example,
thyroid or sometimes when you have a breast
lesion, which is very vascular.
What we do here is just insert a needle without the syringe
and then do a shearing motion, rotate the hub
and then take the needle out of the lesion.
We can also do an FNA with syringe where we apply
where we put a five or 10 cc syringe
and then apply a slow suction
and then also move the needle with rotation.
As we do that, it is very important
to discontinue the suction while we are drawing the needle.
It is very important to biopsy from the right area.
Generally the yield is more from the periphery of the lesion
because very often the center of the lesion is necrotic
and we have, we have a partially cystic and a solid lesion.
It is important to hit the solid area first,
remove the needle and then if required,
take the fluid from the cystic area.
After you get the tissue, it is very important
to take proper care of this tissue.
There are two aspects.
One is making the smear
and second is fixing the slides.
So when we make the smear, we put one slide over the other
and gently pass it over this so that we get a thin
film of the tissue or the fluid which we have aspirated.
The fixing can be done with a fixing solution
or one can just do an air dry,
but it is important to label the slides
as you have fixed them.
So if you have fixed them with a solution, you have
to label it saying that this is fixed with solution.
If you have kept air dry slides, you have
to label them separately.
This is important for the pathologist.

Core Biopsy

We also have automated spring loaded biopsy
guns for true cut biopsy.
They're available in various sizes as well
as different manufacturers have different
types of techniques.
This has several advantages.
We get a larger core of tissue consistently.
Most often a single pass is enough, one can fire it
with one hand and there is actually no increased
risk of complications.
These are newer guns where you can actually adjust the throw
of your biopsy core, either say 15 millimeters
or 22 millimeters depending upon
where you are taking the sample.
When you do a core biopsy with an automated gun, remember
that the needle is going to go at least two centimeters
from where you fire it.
So you have to make sure
that there is no important structure beyond two centimeters
of the point where you fire the needle.
This is very important to remember we get, if you want
to have multiple cores, then it is better to
use a coaxial system
where we have an outer core needle which is very smooth
and sharp, which goes within the lesion
and then through that we pass a cutting needle.

Thyroid FNA and Biopsy

When we do a thyroid FNA, different societies have come out
with different guidelines,
but generally we have to make about 10 to 22
and fro movements every time.
We have to have three
to six passes depending upon the size of the lesion.
And after withdrawing the needle, it is better
to apply a gentle pressure
and then of course make slides out of it.
And as I said earlier, if you have a cystic nodule
with a solid component, hit the solid component area two
or three times and then aspirate the fluid
in a separate syringe.
Here's an example of a thyroid FNA being done.
That's a solid hypoechoic lesion in the thyroid
and we are doing multiple to
and fro passes, as I said, at least 10 to 22
and fro movement, that's a carotid artery which is adjacent
to that in thyroid.
FNA is good enough,
but if the yield from FNA is not adequate
and most important, as in this case if you're suspecting an
lymphoma, then it is better to do a true cut biopsy
as in this case we are doing a true cut biopsy
of a thyroid lesion, which was a lymphoma.

Lymph Node Sampling

When we do sampling from an FNA from a lymph node,
we have an option of FNA or a true cut.
So there is a small lymph node in the supraclavicular area
where we are doing a fine needle aspiration cytology
and this, these are two different nodes here we are using in
plane technique where we are seeing the entire needle
and here we are going out of plane
where we are seeing only the tip of the needle.
If the node is of an adequate size, it is better
to do a true cut biopsy because the yield is much better.
Here, for example, we are doing a true cut biopsy
of a lymph node with a true cut needle, making sure
that the needle does not hit the adjacent structures
after firing it.
So this is a way we do true cut biopsies
of supraclavicular lymph nodes.
We have a very small area to work upon, so
what we do is pass a small 16 gauge needle within
the lymph node and
through this 16 gauge needle we pass an 18 gauge core
biopsy needle and then cut.
Now it's very important that when we do this cut,
when we do this obtain this core, we have to be parallel
to the lymph nodes and go through the bulk of the lymph node
and make sure that we don't go perpendicular
and hit some solid area adjacent to the lymph node.

Biopsy of Other Sites

Once you have mastered the technique, you can do biopsy
of almost anything in the body which is visible to you
on ultrasound except maybe of course an aneurysm.
So here is an example of a carcinoma of the esophagus
where we are doing a trucut biopsy In breast, again,
we have an option of FNA versus true cut,
but for all practical purposes we try
and do a true cut biopsy because the yield is much better
and we can always subject the tissue for hormonal analysis
as well, or molecular diagnosis.
When we do a breast biopsy, it is very important
to go parallel to the chest wall.
One here is a small lesion which is very close
to the chest wall, and as I can, you can see
that it's a very cumbersome technique sometimes,
but you can see that the needle is going parallel
to the probe and it is going parallel
to the chest wall as I fire.
So that I'm not worried about pneumothorax.
This is a very important thing to be done.
When we do a breast biopsy, as I said,
most often we do a trucut,
but sometimes if the lesion is too small
and absolutely adherent to the chest wall,
we might end up doing an FNA as we can see here,
Again in the biopsy it is be in a breast.
It is better to use a coaxial system
because we can take multiple cores.
So here we are again introducing a 16 gauge needle in a
breast lesion and through the 16 gauge needle,
we are introducing an 18 gauge trucut needle
for a core biopsy.
So that's the 16 gauge needle.
The tip of the needle is in the lesion
and then through that we are passing an 18 gauge needle
and then we will fire it once the needle is in position
to get a core tissue as we can see.
Yeah, so that's the, the tip of the needle there
and that's the 18 gauge needle coming through that tip
and that's the needle being fired inside the lesion.
So that's a very small lesion which is very close
to the chest wall, but I'm going parallel to the chest wall
and I'm using a true cut needle to obtain a core.
This can be done very easily.
Remember that when you're doing a guide wire localization,
the technique differs
because now we cannot go through the bulk of the plane of
we cannot go through a larger chunk of breast tissue.
So we have to go as perpendicular as possible
because when the surgeon is going to resect the lesion along
with the wire, he cannot, he has to go perpendicular
to the area where you have put your guide wire.
So this is very important when you're doing a
guidewire localization.

Cyst Aspiration

When you're aspirating a complex cyst anywhere in the body,
make sure that you take sufficient tissue from the walls
of the cyst and if there are any mural, solid nodules,
you take some tissue from that area.
Also for cytological
diagnosis from cysts, one can use
needles which have a longer length,
but usually 22 gauge needle with a long needle
with a long or lid is good enough.
So here we are doing a renal cyst aspiration
and as I go in, I'm trying
to go along the septae which are present in the renal cyst
and that's a liver cyst which is being
aspirated Very often.
If cystic area, there is a tendency to put
some agents, which will,
which will basically scleros that area,
but one has to be very careful when choosing these agents.

Liver and Kidney Biopsies

When we do a biopsy of the liver mass,
especially if the mass is close to the capsule
or it's a subcapsular lesion, then it is very important
to go through a normal liver tissue and then enter the mass
and then fire your gun so that the risk
of hemorrhage can be minimized.
As I said earlier then when we do a liver biopsy,
it is very important to look at coagulation profile
because some of these patients may have a compromised liver
functions with altered coagulation profile.
When we do kidney biopsies for a native kidney,
we generally like to go to the lower pole.
Here again, it is very important that we go into the cortex
of the kidney and not into the collecting system.
When we do a liver
or a kidney biopsy, we always infiltrate local anesthesia up
to the capsule of the organ.
As I said, anything which is seen well on
ultrasound can be biopsied.
Here for example, we have a large lung tumor which was
biopsied under ultrasound guidance
and this is testicular tumor which is being biopsied
and we gave a complete block of the spermatic cord.
So almost everything in the abdomen is amenable
to ultrasound guided biopsies, whether it's a bowel mass,
whether it's abdominal lymph nodes, whether it's an omentum
with omental deposits.
As we can see in these examples for prostate,

Prostate Biopsy

we again make sure that the area of
where we are working is cleaned properly with betadine.
We also make it a habit to inject some lignocaine jelly within the rectum and keep it for some time
before we start with the biopsy.
Some people like
to infiltrate lignocaine in the periprostatic area,
but generally we do not do that.
Again, we take proper aseptic precautions.
Generally nowadays we like
to take 16 cores from the prostate,
so we take eight from each side, making sure
that we take representative samples from all the peripheral
zones on either side.
So that's an example of a prostate biopsy being done.
We generally start with the apex
and come gradually towards the base taking multiple cores
at different levels.
After prostate biopsy, patients could have pain look out,
we ask them to report to us if they have hematuria.
Infection is a known complication
after prostate biopsy, so we cover them adequately
with antibiotics both injectable and oral.
But when we give injectable antibiotics, it is important
to look at the renal function of the kidney,
renal function and give antibiotics which are suitable.
Some patients of course land up with retention amongst drainage procedure.

Drainage Procedures

Very often we have to drain perinephric abscesses.
So here we are putting a larger bore needle, 16 gauge
or 18 gauge into a perinephric abscess
and then aspirating the entire pus out.
Contraindications to needle biopsy, well,
if there is an uncorrectable coagulopathy, if there's a lack
of safe biopsy route of the patient is very uncooperative
or if you're not able to see the lesion, say
because the patient is very obese
or the lesion is retroperitoneal, then retroperitoneal,
then it is better to refer the patient for a CT scan.
By far and large percutaneous biopsies are very safe if
performed correctly
and the incidence of serious complications is very rare.
Intraabdominal bleeding is extremely rare,
but we have to look out for it.
And again, damage to surrounding structures is
again not common.
If your technique is proper,
an infection is actually not seen in practice at all.
Then we have drainage procedures.
Typically nowadays we have drainage catheters which are
loaded over a needle, so all we have
to do is insert the entire set into the area of interest,
remove the needle and keep behind the drainage catheter.
If you're working in a small area
and you don't want to leave behind the catheter,
then we can very often use a gel foam as well.
So that's a pleural tapping which is being done
under ultrasound guidance.
We like to do pleural taps under ultrasound guidance throughout in the sense we like
to keep the needle under observation
till we finish the procedure.
One has to have a reasonable distance
between the pleura in inspiration to avoid any pneumothorax.
So these are small pleural effusions,
which would be very difficult
to aspirate without ultrasound guidance.
And once we have mastered the technique,
this becomes very easy.
Very often when we do pleural taps, we land up
with small pneumothorax and most of them get absorbed
and we don't have to worry about them.
This patient had a coagulation problem and therefore
after pleural tap developed a small hemothorax which
was taken care of.
That's an abscess which is being drained in the neck,
and this was a tubercular cold abscess
and very often to drain abscesses, we need
to have larger needles like 16 gauge so
that adequate we can drain them adequately.
That's a liver abscess being drained.
Generally, if the liver abscess is small in size,
we pass one needle, maybe 18 gauge or 16 gauge
and aspirate out the pus.
But if the liver abscess is large, say
above eight centimeters or so,
or if it has refill, then we like to keep behind a pigtail
until the entire abscess is healed.
As we can see here, that's a nephrostomy being done
for a patient who was suspected to have pus in the kidney.
So that's the local anesthesia being given.
And as you can see, we are going right up
to the capsule of the kidney.
The needle is touching the capsule of the kidney.
That is what you should do when we do liver biopsies
or do any procedures in relation to the kidney or the liver.
Next we are passing a catheter
and you can see the tip
of the needle entering the lower calyx within
the collecting system.
So once we assure that the needle tip is well within the
collecting system, we can confirm
by just removing the inner needle.
Then we remove the complete needle and aspirate,
and there we can see the pus coming from the kidney.
This is a procedure which,
which can be done very easily in the OPD
or wherever is your department.
Very often after transplant we get fluid collections
and they can be aspirated under ultrasound guidance
and this procedure is very often very rewarding
because altered renal functions very
often come back to normal.

Ovarian Cyst Aspiration

When it comes to ovarian cysts, it all depends.
The approach depends upon the visibility of the cyst.
If the cyst is very easily seen transabdominally,
we might do it transabdominally,
but if it is seen better transvaginally, then it is better
to do with a transvaginal scan with a guide,
which is attached to the probe.

Advanced Interventions

RFA is a different talk altogether,
but this can be again,
very easily done under ultrasound guidance.
Similarly, musculoskeletal intervention is a different talk altogether,
but we can do a lot of things.
We can aspirate fluids, we can remove calcium,
we can just tease a cord, a tendon,
and we can inject steroids
or we can also inject PRP to heal a tendon
or a tendon insertion.
Again, vascular access nowadays is best done
under ultrasound guidance.
In the intensive care setup,
we have newer technologies which help us in intervention.
For example, we have an xMATRIX probe,
and in with this probe we can see the needle in two planes
so that we are sure that we are within the lesion
and not outside the lesion.
We also have volumetric ultrasound,
and you can now see the needle in multiple planes so
that again, the accuracy can be very, very high.
These are two examples where we are doing an intervention
with a volumetric probe
and you can see the needle much, much better.
Very often if the lesion is not well seen on gray scale,
one can inject contrast
and typically if you're dealing with the liver,
metastatic deposits in the late phase,
the contrast washes out
and these lesions stand out as black holes within the liver.
Sometimes we use elastography to find out
from which area to biopsy.
For example, in the prostate we are using elastography
and wherever there is a hard area,
those areas will biopsy under ultrasound guidance.
Then of course we have fusion technology
where we can see the lesion on CT or MRI.
Then go back to the ultrasound machine
because ultrasound has a big advantage of being real time.
Fuse the CT/MRI pictures in the ultrasound pictures
and then do the procedure accurately.

Summary

So again, to summarize, any lesion
that is well visualized on a sonogram is amenable
to ultrasound guided intervention.
Ultrasound is a real time technique
and it shows the tip of the needle at all times
during procedure, and
therefore it is extremely safe and reliable.
Thank you so much.