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An introduction to ablation modalities | Ablations: Cryo, Microwave, & RFA
An introduction to ablation modalities | Ablations: Cryo, Microwave, & RFA
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Radiofrequency Ablation (RFA) - Where it's used | Ablations: Cryo, Microwave, & RFA
Radiofrequency Ablation (RFA) - Where it's used | Ablations: Cryo, Microwave, & RFA
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Radiofrequency Ablation (RFA) - How it works | Ablations: Cryo, Microwave, & RFA
Radiofrequency Ablation (RFA) - How it works | Ablations: Cryo, Microwave, & RFA
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Heat Sink Effect in RFA | Ablations: Cryo, Microwave, & RFA
Heat Sink Effect in RFA | Ablations: Cryo, Microwave, & RFA
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RFA Probe types | Ablations: Cryo, Microwave, & RFA
RFA Probe types | Ablations: Cryo, Microwave, & RFA
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RFA Advantages and Disadvantages | Ablations: Cryo, Microwave, & RFA
RFA Advantages and Disadvantages | Ablations: Cryo, Microwave, & RFA
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Cryoablation - What it is and how it works | Ablations: Cryo, Microwave, & RFA
Cryoablation - What it is and how it works | Ablations: Cryo, Microwave, & RFA
ablationablationsargonballchaptercoolcryoablationheliuminfusednitrogenprobeprobessurroundingtissuetissues
Cryoablation probes and ice ball shapes | Ablations: Cryo, Microwave, & RFA
Cryoablation probes and ice ball shapes | Ablations: Cryo, Microwave, & RFA
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Imaging Cryoablation | Ablations: Cryo, Microwave, & RFA
Imaging Cryoablation | Ablations: Cryo, Microwave, & RFA
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Cryoablation Advantages and Disadvantages | Ablations: Cryo, Microwave, & RFA
Cryoablation Advantages and Disadvantages | Ablations: Cryo, Microwave, & RFA
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Cryoblation risks and complications | Ablations: Cryo, Microwave, & RFA
Cryoblation risks and complications | Ablations: Cryo, Microwave, & RFA
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Nodule in right lung | Cryoablation Case | Ablations: Cryo, Microwave, & RFA
Nodule in right lung | Cryoablation Case | Ablations: Cryo, Microwave, & RFA
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Kidney lesion | Cryoablation Case | Ablations: Cryo, Microwave, & RFA
Kidney lesion | Cryoablation Case | Ablations: Cryo, Microwave, & RFA
ablationballchaptercollectingcryoablationkidneylesionLesion in left kidneymedialstricturessystemtumorureter
Malignant melanoma, liver metastases | Cryoablation Case | Ablations: Cryo, Microwave, & RFA
Malignant melanoma, liver metastases | Cryoablation Case | Ablations: Cryo, Microwave, & RFA
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Adrenal gland mass next to aorta | Heat sink / Cold sink | Cryoablation Case | Ablations: Cryo, Microwave, & RFA
Adrenal gland mass next to aorta | Heat sink / Cold sink | Cryoablation Case | Ablations: Cryo, Microwave, & RFA
ablationAdrenal mass next to aortaanterioraortabowelchaptercryoablationfreezemassmicrowavepancreaspancreatitisprobeprobessink
Microwave Ablation - What it is and how it works | Ablations: Cryo, Microwave, & RFA
Microwave Ablation - What it is and how it works | Ablations: Cryo, Microwave, & RFA
ablationactivatedantennasburncentimeterchaptercoagulationconductioncryoablationelectromagneticheatimpedancemicrowaveminutesmoleculesperfusionproberadiuszone
Microwave Ablation Advantages and Disadvantages | Ablations: Cryo, Microwave, & RFA
Microwave Ablation Advantages and Disadvantages | Ablations: Cryo, Microwave, & RFA
ablationburnchapterdamagediaphragmexactmicrowaveprobestructure
Malignant melanoma, liver lesion | Microwave Ablation Case | Ablations: Cryo, Microwave, & RFA
Malignant melanoma, liver lesion | Microwave Ablation Case | Ablations: Cryo, Microwave, & RFA
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Summary of Ablation Modalities - Cost, Time, Risks and Rewards | Ablations: Cryo, Microwave, & RFA
Summary of Ablation Modalities - Cost, Time, Risks and Rewards | Ablations: Cryo, Microwave, & RFA
ablationablationsanesthesiachaptercryoheatissuemicrowavemodalitiesmoderatemultiplepainprobesproceduralsinkvendorzone
Transcript

you can pretty much put plastic at the end of any word you want so if you read or plasti whatever but not ablation truthfully it doesn't sound right ablation oblast ISA so as was mentioned my talk today and beyond ablation I have just one disclosure but consultant for

btg ablation so I guess just a quick raise of hands how many people are due oblations where they work I would hope nearly everyone okay perfect so I'm trying to sort of direct us towards the the way the oblation med modalities work

rather than procedural but we'll show some case examples of of where we can use these the three dominant modalities as many of you know are gonna be the radiofrequency ablation which is the oldest most common one used previously

cryoablation and then microwave ablation I'm not going to talk so much about Ayari it's considered one of the ablation modalities but it's really not done as commonly with ir around the country so we'll start with

radiofrequency ablation I suspect that many of you who are newer to I or maybe haven't used much RFA and people who have been in IR for a long time have used it quite extensively what we know

about RF a is that it was the first

ablation that we came up with all those that used it was first used in 1981 and it was really for the first liver ablation that we did RFA if any of you know about a Bovie knife the idea is the same the modality works the same as a

Bovie knife and still the main modality used in many parts of the world in the United States a lot of people will use it in certain areas but it's it's being slowly replaced by microwave ablation with time so as I mentioned some areas

are still using a fair amount of RF aimost or not I can honestly say that I haven't used much RF a at all I was sort of born into the generation of cryo and microwave places where we do use it or very commonly our Nerada meas for pain

control as well as spine ablations if any of you do the osteo cool system with Medtronic will do kyphoplasty in conjunction with an ablation that would be RFA and then Bowden oblations in conjunction with cement organizations

elsewhere right so in the pelvis if there's metastatic disease to the pelvis and you're going to ablate the lesion and then to cement augmentation the I

deal with radiofrequency ablation is that you have a probe which acts as the

calf the current you then have the pads which act as the anode and when you place the probe in turn it on essentially there's a very small cross-sectional area and there's high flux of energy so lots of

current and then it spreads out over the patient's body and it grounds itself to the grounding pad in so the way is since she works is you generate this very very large alternating current right so the water molecules want to stay in

conjunction with that that current their dipoles arrangement they have positive and minuses and so they're gonna flip around to stay in alignment with that current and that rapid oscillation of those water molecules causes the the

tissue to heat up the way a cinch it works is by coagulation necrosis what does that mean well it's basically cooking a steak it just dies and and that's your your your death related to coagulation necrosis so with our FA

what's important to know is that the molecules immediately next to the probe are what heat up and then everything from there on out heats sort of by passive conduction and I'll describe how microwave works and that's different to

that but the probe tip never gets hot but the molecules immediately adjacent to the probe get hot and and everything propagates from there on out why is that important well it's important because if you rapidly heat the tissue with RFA

you're gonna get charring but some of you might have experienced this when you do the cases the tissue basically gets charred then it increases the the impedance or the ability to conduct it in which case you you limit your ability

to create an ablation all right so charring is a problem and it increases your impedance which is essentially the resistance to making an ablation cavity and then that decreases the ablation size and so that's really

one of the main reasons why people started moving away from RFA is that you really need tissue that's going to conduct this electrical current well and it's difficult to predict what tissue that's gonna be and so the goal with RFA

as with any other thermal ablation is to get the tissue temperature to between 50 and 100 degrees Celsius and then slow temperature rises are best right so however you want to achieve that slow temperature rise you want to do it

slowly rather than a rapid increase which is the opposite really of microwave ablation radiofrequency

ablation also has a little disadvantage than that I don't know if you folks have heard of heat sink but the idea is that

if you put the probe immediately adjacent to a blood vessel that blood vessel is gonna suck the temperature away and so that you cannot oblate around blood vessels particularly well because the blood flow rate since

you just washes it out it's called heat sink effect and this is essentially showing infrared image of of an ablation how if you put a vessel nearby it stops the ablation now that can actually be used as an advantage depending on where

you're doing an ablation but truthfully if you're doing it in the liver and you're next to the portal vein or something like that it becomes a bit of a problem and any blood vessel greater than three millimeters is our concern so

we're going probes I think many of you have used our FA there's all sorts of different probes right so the most common well one of the most common ones is a probe like a Levine probe and what it does essentially is it increases the

number of tines so you put the probe in and you deploy these tines and it increases your ablation size a lot of companies went towards just a single probe and they infuse saline through the probe which will then decrease the rate

at which the temperature increases so that you get a consistent slow increase in temperature to prevent impedance other probes will actually infuse saline into the tissues so that it propagates the ablation better and then finally

there's by polar probes where you put two probes in next to one another and the the ablation occurs just between the two probes and so that's a very controlled ablation that's the most commonly what you see when you do the

spine augmentation procedures with the osteo cool system or whatever system you're using that's the bipolar probe approach so as I mentioned the

advantages of radiofrequency ablation or that there's the most research on this

right so if you look up ablation research there's a whole lot of data and research on this as it's been the longest studied so that's always beneficial when you're trying to convince people that they should get an

ablation it's cheap right although some of the problem with that is a lot of manufacturers aren't making some of the devices anymore so to get replacement probes and that sort thing is difficult but it is certainly much cheaper than

the other modalities its gentler than microwave right so it's a slower increase in temperature and you can control it the disadvantages as we mention right so the ablation zone this is probably the worst part about

radiofrequency ablation is that the ablation zone is unpredictable right now we're trying to go towards this idea where we can predict the exact size of the ablation and really with RFA it was more experience related right so if

someone I've been doing them for 20 they can have a good idea how it's gonna it's gonna blade but that ablation zone is very unpredictable it's very tissue dependent right so if you have cirrhosis and the liver is

really scarred down you're gonna get a different ablation as to someone who has a normal appearing liver you have the heatsink effect which as I mentioned can be used as an advantage but usually as a disadvantage and then large large burns

are difficult right so anything greater than 4 centimeters even that is difficult to achieve with RFA it is possible to get skin burns at the grounding pad so if you're gonna do RFA make sure that the patient doesn't have

a hip prosthesis for instance and make sure you know it sometimes patients get sweat underneath the the pads and that can increase skin burns and those pads so that's one of another downside of a radiofrequency ablation so we'll move on

to talk about cryoablation which is very commonly used in a number of organs it can essentially be used anywhere in my opinion with cryoablation as many of you know the different idea is that you have a probe and it creates this ice ball and

that's what's killing the tissues rather than heating the tissue when they first came out with cryoablation they had these really large probes and that really limited what we could do well with technology obviously those probe

size decreased and we were able to do better ablations and safer oblations in patients so it really took off at that point and the general goal once again is to decrease the temperature to about minus 20 degrees Celsius and in doing so

you kill the tissue and we'll talk about the mechanism of how that works the cold spreads Bible directly molecular transfer right so you're starting to cool around the probe and that will propagate to the surrounding tissue

unlike our FA or microwave as the ice ball grows it doesn't impede further ice ball growth right you can continue to build on that ice ball as you increase the amount of argon infused in the increase the number of probes so that's

beneficial and that you can get a massive ablation depending on how many probes you want to place well talk a little bit of how it works so it works by what's called the joule-thompson effect idea here is if any of you've

done cry before you know you have to drag those huge tanks into the room and it just runs through all gone like nothing so when we first started doing cryoablation you had to have an all gone tank and a helium tank they've gone away

with the helium and now you really just need the argon tank which is really nice and that you don't have to drag those tanks around and they're working on actually doing with nitrogen but that hasn't come to fruition yet so the idea

is that you take a high-pressure gas right so it's in the tank it's pressurized it gets run through the center of the probe and then as it comes out the tip will not out the tip of the probe and within

the tip of the probe it goes to low pressure and that change in pressure allows the temperature of the probe tip to cool right and so if you're using argon or oxygen or nitrogen that'll cool if you're using helium it'll actually

heat the tissues and so that's why we used to have argon and helium to be able to to freeze and then actively Thor so as I mentioned the argon comes from a pressurized tank you have this dual chamber probe that allows the gas to

expand and as it expanded pools heat from the surrounding tissues so as many

of you have worked with cryoablation you know they have 12 different types of probes and each probe is a different Ice Bowl that they they mark it as all this

ice force probe creates a very oblong freeze and this ice rod will create a slightly different freezin you can use an ice pearl which is a more rounded freeze and that is that in order to get the length of the ice ball depends

really on the probe insulation so they've insulated the probe prior to even putting it into the packaging and in doing so you can predict the length of the ablation the diameter on the other hand depends on the rate of

transfer of energy right so if you're putting a lot of energy into that you can create a more rounded ice ball to a certain extent what I will point out in any ablation whether it's microwave or cryoablation propagation from the tip of

the needle from their tip of the antenna is what's most controlled right so if you don't want to damage something in general you want to point the needle directly at it it seems like it's counterintuitive but if for instance you

wanted to ablate near the aorta you want to point the needle right at the aorta because it doesn't come very far off the tip of the probe almost everything propagates backwards and to the side and you can't control that as much and so

kryos the same way that one's here so in

terms of imaging my favorite aspect of cryoablation is the fact that you can see the ice ball very well on CT and most procedures are done with CT guidance right so as you can see this is

a renal ablation the probe has been placed you can see the ice bowl forming around the probe right so that's very predictable you can see exactly where it is the only problem with cryoablation is that that ice bowl is not

necessarily the lethal ice ball right so that maximal ice ball is really your zero Degree and in actual fact the lethal zone is about five millimeters in from that so anytime you do a cryoablation you want to weigh over

freeze essentially to get those margins that you want so that's one important thing to remember the ice ball is not the lethal it's really five millimeters short of that okay so a little more information by cryoablation you don't

have to spend too much time on this but the idea is that the more energy you put in the larger ice ball you can get and so essentially more probes you place can just supplement that energy to increase the size of the ice ball so advantages

of cryoablation it's gentler than both microwave and RF a you can use it in a lot of locations because of that you can visualize the ice ball with CT multiple probes means potentially huge ablation zones and I'll show you an example of

that it's not painful and for me I know that I don't know about everyone else in the room but our anesthesia assistance is is very spotty or sporadic so it's nice to do stuff with conscious sedation in which case cryoablation you can

absolutely do most places with conscious sedation it's not painful at all whereas if you've done microwave you know the moment you turn the probe on the patient wants to punch you so so it's not particularly painful you can do it with

sedation and it has this immuno genic response that we're starting to learn more about right so when you cook tissue your since you just cha reverie and you just cook all the proteins and all the membrane of the cell with cryoablation

you actually keep some of the proteins in tact so what happens is as the cell dies your immune response comes in and it recognizes those tumor antigens right those tumor proteins and there's been lots of reports of where you oblate for

instance a renal mass and the patient's lung nodules will regress because of that so that's a very nice feature of it is that's got this immuno genic response and I'll use that often times if I'm doing a lung ablation for instance and

there's other nodules you can see a regression of those nodules the disadvantage as well you need you know there's these repeated freezes right so you do these freeze thaw cycles you go ten fighting you know ten freeze five

for ten freeze five for that ends up being a pretty long freeze time right and even if you do the triple freeze protocol which I can talk a little bit in a bit here you can see it ends up adding up a lot of time so the time you

save on not putting the patient to sleep and getting general anesthesia actually lose on the backend when you're standing and staring at the probes freezing whereas my crew of ablation as me as you know 10 minutes and you're

done there is this idea of a cold sink so like RFA if you put the probe right up against the blood vessel it's unlikely that that ice bowl is going to propagate into that blood vessel and you can use

that to your advantage once again I'll show you an example of that but cold sink is technically also a disadvantage and one of the main things people worry about with cryoablation is the bleeding aspect right so unlike our fa or

microwave you're essentially cooking the tissue it's a Bovie right you're very unlikely to have bleeding whereas cryo you freeze the tissue and when you thought all those blood vessels are now very porous and they can bleed and so

one of the concerns with cryo is that you have bleeding and you you'll often see this especially in renal and long and then do some early studies where where physicians were doing large liver oblations and they were getting into

something called cryo shock which we'll talk about in a little bit that's probably overhyped from the earlier studies but for that reason many people do not use cryoablation in the liver they would prefer to use microwave

so the idea with cryoablation as I mentioned you create ice crystals in this the tissues outside the cells and then the water rushes out of the cell the ice forms then within the cell and when you thaw the water rushes back in

and this is essentially this whole shift of fluid from one to the other it causes the cell to die but the cell doesn't die like it does with microwave it going to go something called apoptosis which essentially means the

cell decides it wants to die right so it dissolves all of its membranes and whatever else the proteins are then left available for your immune system to help clean things up and that's for the immuno genic response that we talked

about earlier other things you worry

about with cryoablation if you put the probes in and you create an ice ball and then you try and pull those probes out you can cause something called organ fracture basically and

essentially the idea is that you've trying to pull an ice ball out of a kidney or the reason you can tear that organ and it can have some pretty substantial complications related to that so once I've placed probes and

started freezing I don't touch them again even if you don't like where they are you don't want to pull them and move them around addition to that at the end of the case I'm always in a rush to get the probes out and you do this act of

thought thing and it's two minutes can I pull the probe I can I pull the probes out in the Reptoids I calm down calm down the idea that if you pull those out too early you can fracture the organ and

then as I mentioned with liver oblation specifically cryo shock was a concern these large liver oblations could cause the patient to become hypotensive going to di C raspberry compromise it was a big deal in the early studies and so a

lot of people stop doing cryo for liver now you're seeing a little bit of a resurgence of that but most still will do microwave for liver ablations

something some case examples of where I use cryoablation right so this is a

patient who has a nodule in the in the back of their lungs in the right lower lobe and basically I'll place two probes into that notch on either side of Brackett the lesion and then three months later fall up you can see a nice

resolution of that nodule so when it comes to lung a couple things I'll mention is if the nodule is greater than eight millimeters I'll immediately go to two probes I want to make sure that I cover the lesion whereas microwave it's

pretty rare depending on what device you're using for you to put more than one probe in so some people's concern with cryo in the lung is more probes means more risk of pneumothorax but you can also see surrounding and proximal to

where we did the place you can see the hemorrhage that you see so if those of you out there that are doing the lung ablations you probably have physicians that are using something called the triple freeze protocol right so the

double freeze protocol is the idea that you go ten minutes freeze five minutes 30 minutes freeze five minutes thought well what we saw was lung early on in the studies was a very large ablation a freeze to start with caused massive

hemorrhage patients were having very large amounts of hemorrhage so what we do now in lung is something called a triple freeze protocol we'll do a very short freeze about three minutes and that'll cause an ice ball to form and

then we'll thaw that in other three minutes three minutes of thawr and as soon as that starts to thaw we'll freeze it again and we've shown us a substantial decrease in the amount of hemorrhage so if you're doing long and

you and you you're told to do a double freeze protocol perhaps suggest the triple freeze is a better idea so that's three months later so another example

here we have a MRI that shows a lesion in the left kidney sorry I don't have a

pointer here really but you can see the lesion in the medial part of the left kidney there couple probes are placed under CT guidance you can already see the beginning of the formation of an ice ball there this is the second probe you

can see the ice ball forming and there's a good example of the ice ball it's got good coverage of the the lesion as well as a good margin around that cryoablation tends to be less detrimental to the collecting system of

the kidney so some of the concerns when you do renal ablation is that you're gonna cause your read or strictures or urine leaks because you're burning the collecting system essentially with cryoablation you tend not to see that

you don't have to use something called pilar profusion is often right the idea with pilo profusion is you put a small catheter into the ureter and you infuse the kidney with cold saline so that the collecting system stays cold while you

while you burn the tumor well you don't often times have to do that with cryoablation so that's one benefit of it and then this is a one month later scan this is the normal appearance you can see the ablation zone that and the

resolution of the tumor will follow these up for a few years to make sure that all that tissue goes away and this

is example as I mentioned about doing very large ablation so this is a lady who hadn't malignant melanoma and she

had metastases to liver we basically placed six probes into this mass as you can see there on that CT the image on the right is the appearance of those six probes it's all excited about how many probes I placed in this patient

like it's a game and then I just watched an ablation talk with a guy put 16 in so that didn't really make me feel much better so so we have six probes here and you can see what we what you do when you have lesions that are in the soft

tissues and you're worried about freezing to the skin you can have injury to the skin right essentially frostburn and so frostbite sorry and so what you can do is you can take either a warm glove fill it up with saline and put it

with the fingers amongst the probes so it keeps the skin warm because you don't want to freeze the skin or what people are doing sometimes as well as they've just put some gauze around all the probes and they spray that goes with

warm saline I just take one of those leader bags of saline put it in the microwave for a couple minutes and then just fill fill the bowl up with it and just spray the gauze on that or you can do the glove technique the main idea

here once again is you don't want to get skin injury when you do these and as you can see a pretty sizable ablation around that entire tumor you can even see the lightening sign which is the low attenuation sort of lightening looking

structures within the ice ball which is cracking of the ice ball as you form but you will see what this is immediately after the procedure the patient will have a very hard ice ball under their chest and it takes about an hour

for that to melt so if you notice bleeding off towards or what is perceived as bleeding before you panic you should realize that that ice pole is going to melt and it's going to come out the holes seep out of the holes that you

created so oftentimes if it's sort of a blood tinge fluid that's really just the ice ball melting in the fluid coming out of the the sites that you've punctured

and then one more example just to sort of illustrate the idea of a heat sink or

a cold sink right so this patient has a mass in their left adrenal gland right next to the aorta it's just anterior to the kidneys so the problem here is if you put a microwave ablation probe right next to the aorta you're likely to burn

the aorta and if you want to point the microwave ablation probe directly at the aorta well there isn't really a good window for that right you would have to go through the kidney you'll go through bowel and on route to getting there so

really I elected to do cryoablation right so that's the mass that's the aorta so you're obviously worried about injuring any order you place two probes into the lesion they obviously are streaking us out right now but that's

the aorta right there so we are four millimeters away from the aorta with these two probes you would think you'd be concerned about damaging it but using that cold sink effect you can see how the ice boss actually carves around the

aorta so you can get a really nice ablation on to that structure with that Waring that you're damaging the aorta or any nearby big vascular structure now that doesn't happen with pancreas if you freeze into pancreas you're going to get

a pancreatitis and if you freeze into bowel your bowel is going to have a perforation so that really just is with blood vessels that you can do that

so that was cryoablation and then the final modality to talk about is

microwave ablation this one should be relatively quick because the idea is pretty simple right this probe is got this electromagnetic energy it's in between the 924 50 megahertz range and basically like RF it causes the water

molecules adjacent to oscillate right so excuse me as you can see it creates this zone or these this this area of electromagnetic activity and all of the water molecules in that area will be activated at once

unlike RF a right so when it's right next to the probe the water molecules oscillate and then the temperature propagates by and by conduction this will essentially create this zone and that

immediately we'll we'll activate those tissues so if you've done microwave ablation you know if you do an ablation of a hundred watts for two minutes you'll get a three centimeter burn it's literally instantaneous as you turn it

on you get this huge burn and then after that anywhere between two minutes and ten minutes you're really only getting about another centimeter of burn and the reason you're doing that is because that's the the passive conduction so it

is very rapid it doesn't have the heat sink issues that RFA does as I mentioned there's this radius of molecules that are activated around the probe the size that radius depends on the wave link and the probe properties there are no

impedance issues so unlike RF a where you want to heat slowly microwave is instantaneous and it just cooks the tissue around the the probe many of the antennas have internal saline perfusion and that's just really to generate

uniform heating and prevent the heat from propagating along the shaft because you obviously don't want it to propagate back towards the skin same ideas are FA right so you want to increase the temperature to greater than 50 degrees

Celsius for about four to six minutes you get coagulation necrosis and you need about a point five a five millimeter margin on that advantages a

microwave as I mentioned the reason people are switching to microwave is

that it's a very predictable burn right a lot of the companies are coming out with software that will give you an exact definition of what the size of the ablation is going to be like and that's very reassuring for the physician if

they're gonna put the probe direct it at some sort of structure they don't want to injure having an exact prediction of what that's gonna look like is very very reassuring so that's why a lot of people are going towards microwave it's very

quick there's no grounding pad issue there's no charring there's no heat sink it's ten minutes essentially the disadvantages is it's a hammer right so when you put it in you

turn it on you're getting a powerful burn so if you if you've got it somewhere wrong like it's up against the diaphragm or something like that you are gonna burn that structure so you just have to be careful with that and once

again the main property there is if you point the probe towards the structure you don't want to damage whatever it is you're unlikely to damage that structure because it will not propagate beyond the

tip and I'll show an example of that so

right so this is that same lady actually with the malignant melanoma she has a lesion in her liver it's sort of the circumscribed structure we're in right next to the gallbladder there so we placed the probe actually under

fluoroscopic guidance with combi Ct we have a catheter in the hepatic artery so we're gonna inject some contrast and see what the ablation zone looks like but as you can see with injection of contrast very well

delineated margins on that ablation so I could tell with a lot of reassurance like I said that that we're not burning anything that we're worried about I'd say here's an example we've burnt right up towards the gallbladder but didn't

injure the goal though so that's very very nice to know so that's the benefits of microwave ablation in essentially you can use microwave nearly anywhere people are using a lot in renal and and liver nowadays you can use it in lung although

some issues with microwave is it is painful so if you burn the chest wall with microwave you're gonna know about it afterwards whereas cryo you can do near nerves like in a costal nerves and you do just fine so just a quick summary

of all that all the the probes and the modalities I'm sorry so RFA you can have multiple probes the cost is cheap it's quick but the ablation zone is small and you have this heat sink issue the procedural pain is moderate but the best

attribute is that it is cheap so if you don't have a lot of money for ablation RFA is the way to go cryo on the other hand you can put in multiple probes which means you can get just enormous burn

I'm sorry ablation sizes but the time is slow right so you're gonna stand there for a while while the ice forms and freezes and forms again you get a higher risk of bleeding there's a moderate issue of heat sink effect or it's really

cold sink if you will but the procedural pain as I mentioned is is low so you can do with conscious sedation and my biggest benefit of that I perceive with cryo is the ability to visualize that ice ball and then finally microwave

which is the new kid on the block will you can use single or multiple probes depending on the vendor it's it is expensive depending on the probes you use in the vendor that you use but it's very quick as I mentioned 10 minutes

usually you can get a pretty sizable ablation zone size some will advertise up to four and a half centimeters which is pretty good size you don't really want to be doing a whole lot of ablations in most organs if the lesions

more than four and half centimeters so that's very comforting to have that large ablation that's very predictable there's no issue with heat sink but the procedural pain is high so if you want to do microwave you're gonna more than

likely have to use general anesthesia or somehow find a way to mitigate that pain and that's all I have on ablation so there's any questions of entertain them

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