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RFA Probe types | Ablations: Cryo, Microwave, & RFA
RFA Probe types | Ablations: Cryo, Microwave, & RFA
chapterMedtronicOsteoCool RF Ablation System

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

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

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

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

so the treatment protocol there are multiple plan phases in this trial phase one is a dose defining study for phase two and phase one the problem primary objective is to define the appropriate dose for the Phase two this space is

completed and it had 23 patients enrolled phase two is trans arterial terrapass amine embolization versus trans arterial chemoembolization so far there are an additional 11 patients enrolled there is a phase 2a

which is trans arterial terrapass mean EMBO with antibody which includes patients receiving anti pd-1 monoclonal antibody immunotherapy at an outside facility prior to their first tpz procedure in iron alright so terrapass

mean is a very I'm gonna read this one off for you as well syrup as mean is a very unique cytotoxic agent that is activated under conditions of hypoxia it is a bio reductive agent that is activated by cellular reductase such as

cytochrome p450 reductase to generate nitrox ID radicals through a one-electron reaction in the absence of oxygen nitrox ID radicals include single and double strand break and DNA to cause

cell death because of this property terrapass mean exhibits 15 to 200 times greater toxicity and hypoxic cells compared with oxygenated cells this agent has been shown to be a radiation sensitizer and synergistic with platinum

compounds so tpz is stored at room temperature and must be protected from light during storage and administration so in phase one tpz was originally given our intravenously I've got a photo there of the med fusion pump that we had to

use as the pediatric in future and then the lapel dal and gel foam so patients received intravenous TPC five minutes prior to the injection of the embolizing agent slip iodine gel foam the IV infusion lasted two to four minutes and

was to be completed the five minutes prior so we are currently in Phase two which again is taste versus tape and the primary endpoint is to compare the efficacy of tape versus taste based on progressive free survival progressive

free survival is a duration from randomization to the date of the first evidence of progression

bit in comparison to the US or try to at

least if I get this thing to work there you go so you know and compared to the US China the population is 1.3 8 billion so you're talking about a population that's for apps four times the United

States you know we always think about things and we think about everything we do in Western medicine and you know the vastness of that country and the amount of patients that are there I mean really it's its own income comparable you know

us you have thirty three twenty three point 1 million much less people you're in a much less diseased State 31 000 hospitals in China compared to us we got 6 200 hospitals really that are doing any type of case in procedure loads and

you talk about the size of the hospitals now they have very small hospitals you talking about 50 bed 40 bit hospitals and the world's largest hospitals actually in China as well it's 8 000 beds and they're predicted by 2020 to be

up to 10 000 beds in the u.s. the largest Hospital based on beds and I'm not talking about like systems or ID and so based on beds is New York Presbyterian Cornell will in their 2000 36 so you can kind of see that disparity

right there and when we talk about the Chinese population unlike what we see in Europe right now in the US or receive reduction in cancer rates across the board for multiple reasons new medications new interventions China

cancers rising and it's the highest rates of lung liver gastrointestinal cancers in the world make keep rising it's amazing when you go over there and we'll talk about this a little bit you know I went over there as you know a

Western colleague training Western ideology and medicine and you think you didn't go there and you're gonna be able to share all these new techniques I mean interventional oncology it'll blow your mind the number of procedures

you'll go in there on the board and they'll be 25 cases in one day for one practitioner to do so it's kind of the the amount in volume you can really learn a lot we're going to talk about that a little bit more in depth as well

so you know interventional radiology in

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

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

so take a minute to imagine well as ever you guys do anybody doing clinical trials in your facility one two okay and

Paul so take a minute to imagine how you would feel would you be excited worried where do you start and how do you keep everyone involved informed how do you prepare the department so the key to a smooth transition requires a project

manager to develop a project plan adhering to the protocol and task requires knowledge and accountability smooth communication between all involved increases the sense of unity amongst the staff successful clinical

trials should cover the entire scope of the protocol some things we considered for our project or the length of time the trial would take and the number of patients being enrolled what resources were already available and what did we

need in addition who would be responsible for which task and how it would go from one part of the process to the other communication between tasks and ensuring that the ones prior got done and the ones after would continue

problems who would problem solve so I'm not expecting you to see the details but I wanted to show you the schedule of events which was included in the research protocol it's easy to follow and it helps understand the entire

process providing a quick glance of which days the patients would require an appointment or testing to be done the patient's are screened during clinic visits with the MD a nurse practitioner patients can expect a detailed HMP

medication review CT MRI imaging EKG lab work hearing tests consent for research and anesthesia screening the nurse practitioner has helped with scheduling all the screening exams prior term Worman

the NPS had additional work trying to get these patients scheduled themselves they had to override the facility's scheduling process already in place all the patient appointments had to be on specific days and in addition a

convenient time and trying to keep these patients compliant so I was going to show you a video but I wasn't able to to download it if some are you're familiar familiar with the chicken little scene the sky is falling

he basically creates panic from his own fears so this is an example of what could happen when information is not available and the staff are not prepared panic mode so at the start of the trials there was no department manager our

newly hired supervisor was wearing three hats as a manager supervisor and more importantly she was just learning about ir the department was preparing for construction to begin which entailed moving cases to the o.r suite and having

to convince the hospital that our patients would have to recover and another unit by other staff nurses our supervisor offered education and support to ensure the accepting units had what was needed to succeed and feel competent

in recovering the AI our patients but it wasn't easy we were understaffed working on hiring both nursing technologists and nurse practitioners we were also just converting moving over to epic so we had

problems getting our orders in place our nurse navigators took the initiative keeping the information as organized as possible and dr. B today offered an introduction meeting prior to the enrollment of the first patient but

there were ly details left unaddressed and regardless tpz trials began because there are multiple pharmacies at large facilities such as UC Irvine one of our nurses created a diagram to help better on

the process of getting tpz on procedure day so when there's an issue you have to know where the process begins and ends the ten steps involved the research coordinator child cancer center pharmacy which they're in charge of research and

the inpatient pharmacy which is where IR is used to picking up their medications from you can call either of the three involved and not get what you want unless you know what the process stopped the diagram shows the complete process

going from orders confirmations second verifications preparation initiation release and dispensing tpz having the tpz available on the day of the procedure was its own involve tasks so nursing had a lot to be concerned with

the physical exams like I said we were started off and we were having construction done so the big question was who was going to bring these patients back and where were they going to be these were 15-minute exams but we

really didn't know what to do with them it was something as simple as height and weight but to train all the 15 nurses that we had was a little bit stressful patient lay is on these patients were being scheduled on specific days and

they needed specific phone calls no one was really familiar with the protocol except for the NPS and the nurse so our question the nurses was who's going to take care of their calls and their questions and what about insurance and

authorization we had no idea when things came through and said it wasn't approved or wasn't paid for we didn't know what to do about it the tpz orders the pump the IV pump that we needed we had no training on it we

didn't have special tubing we didn't know if there was any risk involved for the nurses and the techs the nursing again the labs the frequency of the labs where the order is going to be an epic epic were they going to be specific or

were they just the standard orders overnight observations hell these patients would be monitored for and what could we expect anything different from the chemo ambos the radiology techs they were concerned with

the positioning bacome being software the radio translucent leads and again special handling of tpz and then recovery any non-standard orders for tpz compared to chemo Ambo there were a few so we were concerned with that it all

appears to be standard and easy however our circumstances were not optimal at the start after several months the department hired a nursing manager and nurse practitioner ir received support from the non clinical research

coordinator and the learning curve plateaued the department now has a defined point person a defined III IR RN to focus on we've initiated a collaborative working team with IR RN + P and research coordinators while

looping in our investigating md guidelines and protocols have been rebus revisited and redone explicitly per trial study the nursing has created a combined a common binder for all the trial studies which include the

protocols and preference and this is continuously being updated increased colleague interactions and communications between the research coordinator the NPS and the RNs for a better patient experience have decreased

delays and service improved communication with PPC U which is where our long-term recovery patients go are now guided and have assistance from the RNs research coordinator communicate via email and they come to our physical

meetings for updates and changes we now see increased participation in the IR staff and the trial studies and cross-training I would expect any clinical challenge any clinical trial to have its

challenges but the better prepared you are at the start the better experience you will have so this is our pre procedure orders this is what was different from the standard clinical trial patients require blood draws and

EKG monitoring so we had a second IV and a second pulse oximetry because because of the comb being imaging we needed to have full socks on both the upper and the lower extremities antiemetics are not

included in the orders as they would be with chemo ambos and because there are eight plus EKG sets required during the procedure the patients will wear two sets of EKG leads one set for the monitoring and the second set used for

EKG recordings for the research the additional work involved with clinical trials was too demanding on one single RN these procedures are now scheduled with to procedural nurses post procedure orders vary some as well the protocol

requires again lab draws and triplicate EKGs these labs and EKGs are time from the time of T Finzi injection the EKG triplicates are at 1 2 4 6 10 and 24 hours post injection various PK labs measuring the pharmo kinetic levels of

tpz are also required post injection at 1 2 4 6 10 and 24 hours post in addition if these patients become free bile with a temperature of greater than 101.5 protocol requires blood cultures be sent and again you must notify doctor Abhijit

a patient requires anti-nausea medication pain a subjective however the clinical trial patients also have a PCA ordered

I think we've talked a lot about this all through the this conference and with

our SAR partners about the vulnerabilities into the procedure areas we have a heightened risk of adverse events in procedures that are happening in nan-oh our areas ironically you know again the patients are twos deemed too

sick to go to the OU are and they come down to a remote area an interventional radiology hence the need for standards and streamlining and communicate and collaboration again we have you know increased acuity of our patient

population again increased volume of low-risk procedures on high-risk patients remote settings within the hospital our interventional radiology suite was buried behind our radiology department behind Diagnostics it was you

know signage wasn't very good and you know it was behind two double doors that needed to have badge access so that was oftentimes you know something it's minor but it was major when there was an emergency there was a lack of

significant team-building training and I can talk we'll talk a little bit about what kind of things you can do in your organization's that are really low cost for team-building training and then the procedure lists we know that they're

experts in their procedures but they're not trained in crisis management so and they you know luckily I have a team and I had a team of physicians that were aware of that and so we worked on methods of changing that supporting them

and supporting our team so again safety

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

interventional perspective I talk to some of my colleagues you look at this handsome devil right here you guys know

dr. Kumar fantastic guy from Rush University with dr. arseling back there you know Kumar when I asked his opinion he was over in Guangzhou with si our initiative as a visiting professor you know one of the things in his main

for us was that you know even though the government limit some of these things that they want for excess it was amazing to him what they do with what they have you talking about very skilled physicians that we're doing intervention

very complex cases with but out the tools they probably need to do them and certainly when we talked about PA D which is very under-diagnosed and undertreated they're given the tools and the abilities they definitely want to do

more PA d work they just don't have exposure to it and then I talked also to David Trost from Cornell who's also a good friend of mine in ecology that's been overseas and you know his perspective is that you know when you

talk to the Chinese physician the majority of them are very aware of the clinical research going on here in the u.s. they're very well plugged into international societies and know what's going on so when you talk about them

they will speak very eloquently on on the current trials and clinical you know things going on that's you know like I said it was very surprising to me you definitely are dealing with colleagues of equal or even more so international

knowledge than you would imagine so

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

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

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

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

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

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

no way around this I'm gonna read to you the inclusion criteria right off the protocol it's kind of long so confirmed diagnosis I wrote some single line there that can help you follow along confirm diagnosis of HCC number two patients

above age 23 patients with single or multiple nodules HCC who are unsuitable or unwilling for surgical resection or RFA the largest tumor nodule should be less than 10 centimeters in the large largest diameter total volume of tumor

cannot exceed 50% of the liver patients are candidates for trans arterial embolisation no tumor invasion to portal vein or thrombosis and main and first branch of the portal vein 5 patients have no lymph node involvement or

distant metastasis 6 ECoG score at 0 to 1 with no known cardiac pulmonary or renal dysfunction 7 child pew score group a and B 7 eight patient should have measurable disease by contrast MRI nine prior local

therapies such as surgical resection radiofrequency ablation and alcohol injection are allowed as long as tumor progresses from the prior treatment and the patients are still candidates for tae 10 patients have normal organ

function based on some labs eleven patients are able to understand and willing to sign the informed consent and twelve men and women of childbearing age need to commit to using two methods of contraception and the exclusion criteria

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

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

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

you know the most common procedures in China this is kind of interesting I was blown away by this when I did the research on this I knew when I would go

into the hospitals and I was all over for I've been to Beijing shanghai nanjing to even the smallest little place is up in northern china and the one thing that blew me away I'm looking at the board and I'm seeing neuro case

after neuro case after neuro case I'm like it got 10 Narrows and and a pic line I'm like it's an interesting interesting Dysport of cases and the reason being is in China they consider diagnostic neuro

so neuro angio to be the primary evaluating factor for any type of neurological issue so you're not getting a CT if you come in with a headache you think you're gonna go get that cat scan now it's generally what not what they do

so you're talking about a case and I'll give you the case matrix of the break-up it's just proportionately high for a neuro very well trained in neuro and most of the guys that are trying to neuro very similar to what dr. well Saad

said a lot of the guys in Africa are trained in France so other neuro interventions have trained in France or lipstick in China and have received European training on that so you know the level of what they're doing some of

the stroke interventions some of the ways they're going after these complex APM's they'll Rob well anything you'll see here in the US so it is quite interesting to see and the second

largest is taste hepatocellular carcinoma is on the rise it's the highest level in the world is found in China and Korea for that matter and there's many reasons why we can go into it some of it is genetic factors and a

lot of societal factors alcohol is a very liberally lie baited in China and there is problems with you know cirrhotic disease and other things that we know could be particular factors for HCC so always found that very

interesting like I said I would go into a hospital and I'll see a PICC line a hemodialysis catheter and then 20 tase's on the board in one day so it is quite interesting how they do it and then biliary intervention stents tips and

then lung ablation you know the highest rates of HCC biliary cancer and lung cancer found in China and once again when we talk about lung cancer what are those contributing factors you're talking about certainly a genetic

component but mostly it's lifestyle factors smoking is prevalent in the US and in you know in Europe and in some areas in Asia we've seen obviously a big reduction in smoking which is fantastic China not so much you don't see that

it's a societal thing for them and unfortunately that has led to the the largest rates of cancer in the world in lung cancer so lung ablation is a big procedure for them over there as well so procedure breakdown this is kind of some

of that breakdown I was telling you about that cerebral procedure is some of the most commonly performed and you're talking about at very large numbers they're doing neuro intervention because they do it for die

Gnostic purposes and I would that kind of blew me away when I found out they do have cast scanners and certainly for trauma and things like that they'll do it but the majority of the stuff if you come in you have headaches you might end

up in the neuro suite so it's quite interesting how they can do that tumor intervention very high like I said you have the highest rates of HCC in the world you're getting cases they do have y9t available and in fact China just

made their largest acquisition ever with the by what you guys know a company they bought surtex there's a Chinese company now it got bought by China now the interesting is they don't currently have a whole lot of

y9t over there but they just opened up some of their own generators so they can actually start producing the white room 90 and I think you'll see probably a increase in those numbers of y9t cases but to date the number one procedure for

them is taste and they do a lot of them you know like I said on average a community hospital setting you might find 15 or 20 cases a day with three interventionalists so compared to what you guys do there's probably not many

people here unless you're working at a major institution that there's nothing but cancer doing 20 cases a day and I promise you're probably not doing it with only two interventionalists so it's amazing how fast and effective they've

gotten at and below therapy and unfortunately it is necessary because of those elevated HCC levels and like I said when we look at some of these things it's I go over there and I'm looking at the board there are very few

cases for you know PICC lines very few the frosted grams very new bread-and-butter abscess training procedures like we do here in the US they are very it's the prevalence is very simple it's neuro it stays and it's

biopsy and those are some kind of the big three for intervention in China and there it's such a large volume you get to learn a lot when you're over there and CLI PA D even though it's more prevalent in China than it is here

because smoking lifestyle factors certainly westernization of the diet in China which occurred since the 1950s and 60s has led to a lot of McDonald's and and fast food and things that weren't currently available prior to 1950s you

see a lot of PA d but it is very undertreated and certainly talking to some of my colleagues like whom are oh you'll get to see a little bit later on with CLI fighters one of the things that's kind of frustrating for them is

that it is so undertreated it's very common to see amputations in China instead of actually doing pipe in percutaneous intervention they normally like to go too far and you see a lot of amputation certainly above

normal so that's something I think as an interventional initiative when we look at these things coming from a Western perspective it's definitely something we need to pursue a little more aggressively but there it's very little

oh well you're talking about two you know two to three percent you know maybe up to six percent or PID cases very very low levels so equipment in equipment in

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

China first of all point out look how handsome that guy is right there right that's kind of that guy's a stud no a joke and it's me but anyway interventional radiology in China you

know largest procedural case volume which is quite interesting that 1.6 million procedures a year roughly do you guys have an idea of how many interventional procedures are done here in the u.s. that we consider peer

interventional a year none that's what I'm here for you if you knew that then I won't have to be up here right so anyway o Medicare Medicaid when we look at CMS

and kind of get a rough estimate and then extrapolate looking at that Blue Cross Blue Shield private payer so you're talking about well over twice the amount of cases done yearly in China compared to the u.s. an intervention it

definitely is the biggest future market for medical device innovation when you have that many procedures being performed on that many patients you're gonna need new products there's gonna be new ideas and new innovations

but there are some issues with that in China we'll talk about that that makes it a little bit complex for companies from the outside that have different products that they want to bring into China it can be quite a complex process

and I'll kind of explain that to you a little bit as well you know iris especially was introduced in the 1980s early 80s X News 1983 when it was brought into China and the gentleman who brought it into China actually trained

at the daughter so he back in 1968-69 met Charles daughter and they started having a pen pal relationship and he was brought over in 19 9 and kind of introduced irn to Chinese the grandfather of Chinese intervention

his name is dr. Peng so who's out of Shanghai he's passed away now but you know it's kind of interesting that little historical tie back to daughter you know and and roughly about 7 000 practitioners identified themselves in

China as I are now I will tell you that that could be probably speculative they could be doing if you're a biopsy guy and you're doing you know lung biopsies are you an interventional radiologist in China you are because their process a

little bit different in how they train and how they identify themselves and like I said the thing that's interesting in China they have a Chinese society of interventional radiology there's more members of that than there are but the

SI R so the and I can tell you when you go to their meetings they have a better turnout you know their turnouts about 6 000 members they kind of have to go they don't have much choice that kind of told you gonna go so it does help in

getting that that turnover but it's so you'd have a very large society and they're very well abreast of what's going on internationally and when we talk about intervention you know for many many years in the US intervention

was a subset tied to diagnostic radiology you would have your diagnostic guys you'd have an interventional group you may if you're lucky have one or two recovery beds that you can use down the same day surgery afterwards to send your

patients China has always been very progressive in how they set up their interventional procedural Suites roughly about 50 percent of all interventional radiology departments in China have their own dedicated recovery unit their

own dedicated recovery staff and 1/3 of those are actually their own department so when you go you're going to vir similar to what we have in some of our major large academic institutions where interventional radiology interventional

neuro is separate from the diagnostic radiology department so that's quite impressive like I said you go over to China and you're expecting you know maybe a little bit different things to be a little small or maybe a little

slower absolutely not and certainly from my experience that wasn't the case so

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

includes patients with prior t-ae treatment and liver transplant major medical problems such as cardiac pulmonary and renal disease pregnant or lactating women unable to identify the feeding artery at time of procedure

would exclude participants known diagnosis of cancer other than HCC patients are excluded patients with active infectious disease such as HIV or non-healing ulcer ation and poorly controlled HPV infection are

excluded patients on medication for HPV or HCV are allowed in the study that are required to hold medication on day one of procedure patients with congenital QTC syndrome are preferably a social or associated risk of torsades de pointes

and said antiplatelet platelet inhibitors will require washout periods any major GI bleed in the prior two months of enrollment are excluded and lastly patients who have any clinical evidence of hypoxia with o2 saturation

less than 92% on room air and patients with evidence of arterial and sufficiency or micro angio angiography and any organ due to any reason which could lead to distal extremity hypoxia are excluded all right

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

finally intraoperative considerations positioning for comb bean tpz photo

sensitivity EKG and lab draws and noting the time of tpz injection so i wanted to say a little bit about comb beam all right who has comb beam at their facility just a few less okay comb beam is medical imaging technique consisting

of x-ray computed tomography where the x-rays are divergent forming a cone the scanning software collects the data and reconstructs it producing what is termed a digital volume composed of three dimensional voxels of anatomical data

that can then be manipulated and visualized with specialized software on the left is a standard floral image and on the right is the comb beam so the red shows the vascular angiography the blue is a tumor and the yellow is a feeding

artery to the term or so dr. Abuja lays a B today is heavily involved with research so the procedure room with Combee was exclusively constructed for her so positioning for comb beam I believe

to be the bigger challenge initially comb being requires the patient to have their arms up high and using comb beam technology increases the procedural time it would be difficult for the patients to maintain that position and keep still

without anesthesia we started clinical trials with nurse assisted moderate sedation and soon learned it was very difficult the majority of our HCC embolization --zz are done with with sedation but we're

now using anesthesia for all of it so the lead in this case was Tom the radiology tech which assisted with the placement of the anesthesia equipment and patient positioning our anesthesia personnel are not only out of their

comfort zone in the I are sweet but unfamiliar with tpz trial and how the comb beam equipment rotates completely around the patient the patient is wearing two sets of leads one for anesthesia and the other for research

the leads are radio translucent to reduce artifact and imaging keeping the lid lid lead in the department took some getting used to one set got thrown away one set was found up in the ICU one set was on the

anesthesia equipment it was hard keeping track of our special equipment there so the pulse oximetry and blood pressure are on the lower extremities for cone beam again to avoid artifact and imaging when we first

started using cone beam the nursing staff administering sedation were disconnecting patients from monitoring so there were short interruptions with viewing vital signs it became risky and time-consuming to do

so during the procedure one set of EKGs triplicates are done just prior to tpz injection so the treat the EKG triplicates are basically they're two minutes apart in sets of three and lastly having to keep the tpz in a brown

bag and protected from light during the transfer nurse to position there's the photo on the left upper corner doctor busy day basically draws a tpz through a three-way stopcock under a sterile towel

while the nurse keeps the syringe in the brown bag poking a hole in the bag just to NIF to just enough to expose the tip of the syringe and attach it to the three-way this way the tpz is protected from light these reminder adjustments

however they were difficult from the standard and it took time for all the nurses and techs to adjust all right so this here is just a group photo Tom I've got Tyler on the right Thanh our technologist and ELISA and myself so I

thought this was a good photo to represent radiology many specialties consult two IR but it just isn't quite known yet by the general population and surprisingly by the medical staff as well there is a quote by dr. Rosa be

published quote the reason the public doesn't quite understand is we deal with so many disease entities and so many body parts it's hard to brand us unquote so I don't know if you guys were aware but interventional radiology is now its

own medical specialty so hepatocellular carcinoma is a primary malignancy of the liver and now the third leading cause of cancer deaths worldwide with over

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

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