I think it's sort of. The topic is machine perfusion, the new dawn or optimistic hyperbole?
The idea of a fusing isolated organs is not new.
There was lots of lots of interest in this long before the era of clinical transplantation.
This This image on the left comes from the Journal of Experimental Medicine in 1935,
describing a series of experiments carried out by Lindbergh and Carol, very famous in their own right.
Both his aviator and and researcher found themselves on the front cover of Time magazine four years later,
which doesn't happen to many surgeons or, for that matter, scientists.
And in fact, it was not for another 30 years that another transplant surgeon found their face on the front cover of Time magazine.
But what's this all about? Why are we replacing good old fashioned technology, i.e. an ice box with something which is so complicated, so expensive?
What is it that these two young surgeons are staring at with such interest in this box?
The answer is it's a liver which is functioning. It's fully fused.
It's fully functioning. It's running at 37 degrees centigrade. It's having oxygen.
Is having nutrition. It's been given all sorts of additives to make it function completely normally.
The objective, of course, is to allow it to be preserved without injury and indeed to recover,
to repair itself and potentially to be available for therapeutic interventions.
Well, if we look at liver transplantation on the face of it, it is simply a success story.
Look at what's happened in the UK over the last 10 years, the number of organ donors has increased, which is good.
The number of transplants has increased. We topped over a thousand liver transplants last year on the waiting list has come down.
It's 359 at the beginning of the financial year, but actually it's not as successful, not as straightforward as that.
The demand is going up actually significantly faster than the supply,
and that's because liver failure is increasing and cancer involving the liver is increasing.
Meanwhile, the suitability of the organ donors, rather than the number is decreasing.
Organ donors are on average now older and have more medical problems diabetes, cardiovascular disease, et cetera.
There are more donors who are being declared dead by cardiovascular criteria,
i.e. cardiac arrest rather than brain death, and that brings with it an inevitable injury, a hypoxic injury.
And as a result, these organ donors are actually not as well used as well utilised as we would like.
And in fact, in the UK, slightly less than two thirds of deceased organ donors result in a liver transplant.
And this is associated with a substantial waiting list mortality.
There are about 60 patients died on the transplant waiting list last year,
and even and even then, we are very restrictive as to which patients get onto the waiting list.
So last year, there were almost 6500 organ donors.
Eleven hundred and forty nine livers retrieved. 85 percent of those were transplanted.
And if we look at the split between the brain dead, that's what it called DVD and the circulatory arrest.
That's the CD. That's where the figure of 62 percent comes from, and it's the high risk livers which are very, very poorly used.
So that's really what we're going after. It's these poorly utilised donor organs.
So what's that got to do with organ preservation? We're ready for things.
The icebox has got problems insofar as, first of all,
cooling down biological tissue is not very good for it, and the damage is not entirely reversible.
The second, there is no oxygen delivery in the icebox, and we now know that even at ice temperature,
delivering oxygen is important in terms of the the switch to aerobic metabolism.
As a result,
anaerobic metabolism leads to the accumulation of metabolites and these metabolites from the substrates for what we call ischaemia reperfusion.
And finally, because the organ is not functioning normally in the icebox,
we can't measure its function and work out whether it's a viable liver or not.
That's absolutely fine if the liver is a perfect liver from an ideal donor,
a 25 year old head injury, for example, it's not fine with a high risk donor organ.
These limitations become more severe, so there's lots of interest in machine perfusion trying to do something better than the ice box.
And these four devices shown here are all different devices designed and in clinical trials or on sale for the perfusion of human livers and.
Really, three issues, one of which is whether fusion makes a difference, the second is whether it's important to deliver oxygen.
And third is which temperature to do is that there has been quite good evidence for a long time now that cold fusion
simply simply pumping a solution through through an organ during preservation is better than static cold storage.
And this device shown here is a kidney fusion device.
It's been around for quite a long time, and variants along these this line have been around for several decades,
and there is evidence that it's beneficial in higher risk donor organs.
But developing this in the context of the liver is a much more recent phenomenon.
This was the first paper to describe just that,
which is a very simple machine perfusion system of a human liver, and it was shown to be feasible and safe.
And we are really awaiting more substantial evidence as to whether it adds value rather than just being possible.
But we do know, and this is this is a much more recent phenomenon that delivering oxygen even when organs are in the refrigerator,
even ice temperature is important. And it's all about mitochondrial metabolism.
Accumulation of succinate in the mitochondria is a universal feature of ischaemia, and it accumulates and at the time of fusion.
In other words, the time that oxygen is provided,
there is a reversal of an enzyme at mitochondrial complex to which results in the generation of reactive oxygen species.
A complex one and reactive oxygen species are the essence of what happens when
organs are transplanted and experiences so-called ischaemia reperfusion.
And the reason why the oxygen thing is important is that given giving oxygen
prevents such an accumulation and that works independently of temperature.
And that's the that's the recent finding, which probably matters a lot.
And this concept has been translated into a hypothermic, oxygenated perfusion here in the context of the liver,
whereby livers which have been retrieved with oxygen depletion so so circulatory death,
livers stored on ice for a few hours and then given a brief period of machine perfusion with oxygen.
And the preliminary results of these studies looked very encouraging randomised clinical trial to certain not yet available.
But what we're discussing today is non-Islamic machine perfusion that's recreating the physiological
environment that's pumping the organ with blood at 37 degrees centigrade with option with nutrients.
And this allows normal metabolic activity. It allows prolonged preservation.
It allows viability assessment as you can measure the function of the organ, and it should allow organ repair.
So that's the hypothesis that we are discussing this morning.
I'm not going to hand over to my colleague David Nasrullah, who spent three of the best years of his life working on this.
They were three great years. Thank you very much, Prof.
So as Professor Friend said, I'm going to talk about the clinical application to date of normal thermic liver perfusion.
So the first clinical studies in man were done again here by our group in Oxford.
They were published a couple of years ago in the American Journal of Transplantation,
and their 20 human livers there were preserved using normal thermic liver perfusion
were transplanted at King's College Hospital London and the Queen Elizabeth Hospital,
Birmingham. And that study essentially showed that normal terminal liver perfusion was feasible and it was safe.
And on the basis of those findings, we then moved on to perform a much larger, randomised controlled trial.
So this was one of several clinical trials being run by the COPE consortium.
So the Consortium for Organ Preservation in Europe, it was funded by the European Commission and sponsored by the University of Oxford.
It took place in seven European liver transplant centres so far in England, one in Belgium, one in Germany and one in Barcelona, in Spain.
And we needed to randomise 220 livers into the trial.
And they were randomised in a one to one ratio to either conventional static cold storage or normal perfusion on the machine.
Now, in an ideal world, the primary outcome for such a study would be one year graft survival.
But the problem is graft survival in the UK is very high end.
To power such a trial, you need very large numbers. So we chose a surrogate, and that surrogate we chose was the peak trans Amina's levels.
And we know from a large number of studies that the peak trans manet's levels in the
first week after transplantation correlate well with the likely the patient will die,
the likelihood the graft will be lost, but the patient will survive, or the likelihood that the graft in the patient will survive.
And so we this study had a 90 percent power to detect what we felt would be a clinically relevant 33 percent drop in the peak AST.
We also looked at a large number of secondary outcomes, including organ utilisation,
which is perhaps the most important question facing the transplant community due to the shortage of organs and also preservation time.
The incidence of post reperfusion syndrome. So that's a measure of the degree of hemodynamic instability that a recipient suffers
after the transplant and that limits the organs that many recipients can be eligible for.
Early allograft dysfunction, which is another measure of early graft function that correlates with the later graft survival biliary injury,
which in DCD organs is really what limits their usage because many of those organs suffer biliary injury and biliary strictures.
And then the other aspects listed here,
the way the trial worked was that once an eligible liver was matched to a recipient who was consented for the trial, then the liver was randomised.
It was randomised to cold storage.
Then the organ retrieval, preservation and transplant process all happened according to conventional standard practise.
It was randomised to machine perfusion. Then, a researcher and the device travelled out to the donor hospital, and once the liver was out,
it was placed on the machine where it remained until it was transplanted, and all of post-operative care was continued as per normal practise.
So the the way normal stomach perfusion works, the mechanics of it are shown here.
You, you have a liver in a bowl and that liver is calculated. So there's a cannula in the portal vein hepatic artery and vena cava.
There's a blood based profuse eight which flows out of the vena cava to this pump, which pumps it up to a heat exchanger,
an oxygen oxygenated, and this warms up a fuse eight to 37 degrees and oxygenates it.
And then from there, it's either pumped directly into their Patek vein, and that's a high pressure, low flow system.
So, yeah, high pressure, low flow, or it's pumped up to the reservoir from where it drains under gravity into the portal vein.
And so that's a low pressure, high flow system sort of mimicking your normal physiology.
But it's taken a few years to develop that circuit or to develop the final looking circuit.
This was about 20 years ago, although it looks like it's from the 1920s. But but it's actually essentially the same circuit.
We've got the liver in a bowl, you've got an oxygen tank and various other tubes and so on.
And that appearance has been gradually refined, refined until we've ended up with the device we used in the trial.
But it has exactly the same circuit I described.
The perfused that comes out of the vena cava to this pump travels up to the heat exchanger, an oxygen heater,
and then either goes straight into the hepatic artery or up to a reservoir from where it drains antigravity.
We've got continuous infusions of heparin, insulin, foster cycling and bath salts.
And this display gives continuous, real time information about the metabolic, synthetic and flow dynamic characteristics of the liver.
Once we had travelled out to the donor hospital with the machine. And once the liver was out of the donor.
And so once we got to the hospital, we had to set up the device that come.
There's a naked chassis and a and a disposable set, which is then mounted on the chassis and find with blood to end up with this appearance.
And then once the mother was out of the donor, we have to prepare it. So this is where there's a change in normal practise.
So once the levers that we have our own kit we take with us, we first have to close off.
This is the vena cava with the caudate lobe of the liver there.
So we close off the top end of the vena cava with a stapler and then calculates the bottom and as shown here.
We then calculates the portal vein, the hepatic artery, the bile duct and then transfer that liver into the bowl on the machine and connected up.
And this shows that process, so in the poll here, we got a piece which we remove initially.
And we've then got these and pieces onto which we can connect the countries that are already in the liver,
so this yellow one connects to the portal vein red ones of the plastic artery blue and here will connect to the to the IVC.
And we should have a liver that we prepared earlier coming into screen now.
So this is a healthy looking liver rather than the some of the larger toxic ones we sometimes end up with.
Again, here you can see behind my hand the vena cava travelling through the caudate lobe, which has been kind of lighted.
And we first take some time to arrange the candidates and then get rid of any air that's left just at the end of the tubing.
And connect those Kenya is up.
With the portal vein, there have been cases where there's there have been twists in the portal vein that have been missed.
So we take some time to make sure that is correctly positioned.
And then finally, we connect the hepatic artery. So we're just twisting the port to win here.
So finally, connecting up the hepatic artery and again, removing any gas that's left in the end of the tubing.
And then once that's all done, we open these clamps. And that final tube were just manipulating, is the silicone tube sitting in the bile duct?
And then once that's done, we start the perfusion.
And the first thing you see is flow going into the affected artery and then coming out of the vena cava.
And then finally going in through the portal vein.
And if it's if it's a nice liver, it will profuse, fairly homogenous Lee and it will pink up relatively quickly,
as this one is doing if it's not as nice a liver.
It may be far more patchy the perfusion than it may take a good while for it to have a nice appearance.
But the other good thing about this setup is if there is any, any vessels you've missed, such as here,
there'll be some bleeding in a moment from an adrenal vein that's been missed that can then be addressed and and tied off.
So this it's possible to do further backbench work and preparation of the liver during machine perfusion,
as well as potentially do other therapeutic interventions.
So the way in which the trial panned out in the end was we needed to randomise many more livers than expected,
so we ended up randomising of over 300 livers, of which 62 were withdrawn.
This was mainly because the deceased donors, those who die after circulatory death,
they didn't actually die in the required time period, so couldn't be included.
And that's not uncommon. So we ended up with 270 livers that were included in the trial, approximately 50 50 split between the two arms.
But then there was a notable disparity between the number of organs that went on to be discarded after inclusion in the trial.
So after they'd been retrieved, let's say 32 were discarded in the cold storage, 16 were discarded in the machine perfused arm.
So we ended up with a difference in the number of livers that ultimately went on to be transplanted.
In terms of the results, our donors and our recipients were well matched in all characteristics.
The primary outcome from the trial, as I said, was the peak transfer mannies levels.
So this was sort of the headline outcome, and we powered the trial for a 33 per cent reduction.
And in the end, we saw more than 50 percent reduction in the peak transfer monies, and that was statistically significant.
When this was broken down by donor type thought for brain dead donors.
So they said better quality organs.
The the reduction in PTSD was about 40 percent for DCD organs, which by their nature, are extended criteria or much more marginal types of livers.
That reduction was was over 70 percent, so we saw a much greater improvement in that in that group of donor organs.
Moving on to organ utilisations, and this was the number of livers that were retrieved that ultimately went on to be transplanted, as I said,
there was a notable difference in the number of livers that were discarded in both arms,
with 24 percent discarded and cold and 11 percent in the in the normal thermic arms.
There was better organ utilisation in the normal thermic group.
And this was probably a reflection of the number of toxic livers that were utilised in each group.
So fatty livers have a much higher rate of of non-functional after transplantation, so surgeons tend to be much more hesitant to use them.
But we noticed that in the normal thing, they come, about a quarter of the livers that went on to be transplanted were moderately or severely toxic,
compared to just over 10 percent in the coastal group. And when you look at the characteristics of the discarded livers,
it was notable that many more of those that were discarded in the cold were still toxic.
One of the other problems in transplantation is that the longer an organ is preserved for the poor, the outcomes after transplantation.
So here and here, we've got all the livers in the trial ranked according to their preservation time.
Every red bar represents enormous liver.
Every blue blue bar represents a coastal liver, and they're ranked according to their duration of preservation.
And you can see that in the normal swimming group, the duration of preservation was much longer,
and that was shown in the in the findings from the trial.
And we know that many centres started to organise their theatre logistics, according to whether the liver was on the machine.
So even if we had two livers arriving at the same time,
they simply cued them up rather than trying to open additional theatres and sort of in other cases.
Some of the centres also rescheduled transplants, so rather than doing them in the middle of the night,
they moved the operating time to daylight hours, which again, we know has logistical benefits for the way the theatre departments are run.
As you may remember, temporary perfusion syndrome measured the degree of hemodynamic instability in recipients after their transplantation.
And again, here we saw a 33 percent rate in the coastal group, compared to 12 percent in the normal thermic group.
So there was a measurable improvement in the hemodynamic characteristics of recipients after transplantation,
which correlates with graft injury and also is likely to increase the number of organs that can be considered for some of the sickest recipients.
Another measure of early graft function is early allograft dysfunction, which correlates with later survival.
Here we saw rates of 30 percent in the coastal group, which is similar to those quoted elsewhere with much lower rates than our normal thermic livers.
In D.C. organs, as I mentioned, the big factor that is limited,
more widespread utilisation of such organs is the risk of bile duct complications with as many as one in three patients getting biliary strictures.
As part of this study, all patients underwent an MRI scan at six months after transplantation, regardless of whether they had symptoms.
And this is actually something that had never been done before in any previous study.
So the radiological rate of Billy restrictions in otherwise asymptomatic individuals has not previously been described.
And what we found was that in about 10 percent of the normal thermic DCD livers,
there was evidence of biliary structuring, compared to about 26 percent in the coastal group.
However, this did not translate into any into clinical findings with with only one patient in each arm of the
trial actually suffering significant clinical consequences as a result of these biliary strictures.
So actually, the clinical relevance of these MCP findings is not clear.
And then finally, graft and patient survival we've gone out to two years now.
There's there's no measurable difference in graft survival at two years.
Perhaps the greatest benefit from machine perfusion will be the ability to assess organ viability and to help guide organ utilisation.
And as I said, during machine perfusion, you can measure metabolic, synthetic or hepatocellular characteristics, as well as perfusion flow dynamics.
With regards to restructuring, there's many groups that have tried to look into this during machine perfusion to determine if there's anything
that can be measured while the liver is on the machine that may predict the likelihood of strictures.
It doesn't look like bile production shows any relationship,
but the group from Cambridge have shown that bile P.H. does appear to potentially predict the likelihood of developing
later strictures with patients that had more acid acidic bile later going on to develop ischaemic angioplasty.
Other groups fear that lactate clearance may be a better marker of viability.
We saw that in pretty much all the livers that went on to be successfully transplanted.
Lactate was cleared very quickly from the circuit, although again the group in Cambridge feel that it may not be as good a predictor with some,
but they've had one liver that didn't function after transplantation that did manage to clear lactate.
But I'm going to give a few exact case examples now that will show how the assessment
of organ viability has been used to guide organ utilisation in real clinical practise.
So here we had a severely fatty liver from a 72 year old DCD donor, so poor quality donor, which at the time of the retrieval,
the retrieval surgeon said this liver is awful as perfused, very poorly in situ is not usable.
He phoned the transplant surgeon, who said, I don't want it,
but we were there at the donor hospital already with the machine set up and so on the phone,
we just said, why don't we put it on the machine and see what happens?
And he said, OK, so we put it on the machine, and to our surprise, it started functioning.
So we phoned the transplant surgeon and said the liver is functioning well.
And he said, OK, we'll come to the Royal Free Hospital and we'll see what happens when we arrive there.
About 2:00 a.m. And the surgeon was in his suit and he said, Look, I'm going home now.
You can do what you want.
But if if when I come back in eight o'clock in the morning, you've still got a functioning liver, then come back and talk to me.
So then at 8:00. But he didn't quite say like that, but it's 8:00.
When he came back, the liver being on the machine for 11 hours and 10 minutes,
it had 500 miles a minute going through the artery, a little a minute going through the portal vein that was normal for a liver.
It was making bile at 10 miles an hour. It was using glucose nicely and it appeared healthier than we'd expected.
And the surgeon was surprised, but he said, OK, let's give it a shot.
So we had a patient who was consented for the trial, had a discussion with him.
He was happy to proceed. So we performed the transplant.
When the liver came off the machine, it looked awful again and I got shouted out to bits.
And then once he got transplanted, it also didn't look very pretty inside you,
but it functioned perfectly from as soon as it was Ripa fused and that recipient who went on to make a good recovery.
With that liver still functioning two years later,
that was maybe the clearest example of a liver that would not have been used that went on to be used,
who had other cases, such as a 55 year old's brain dead donor who was quite overweight, who again had quite a fatty liver.
But in this case, what happened was at the time of retrieval, it wasn't noted that if you look over here,
you can see a little vessel that's a left hepatic artery that had been inadvertently divided, not noticed at the time of retrieval.
And the significance of that artery is often unknown. Sometimes these can be tied off.
Sometimes they are important for perfusion of the left side of the liver.
So this liver on the machine?
And it was notable quite early on that the left lobe was very patchy in the way it perfused, although the liver appeared to be functioning nicely.
But we got to the transplanting centre in Addenbrooke's,
and the surgeons there looked at the liver and decided to try and reconstruct that artery during machine perfusion.
So they used the donor only Akashi, which you can see here, the external and internal to reconstruct it.
You can't really see it well, but onto the left hepatic artery.
And and as the perfusion continued, after that reconstruction had been performed, actually,
the liver went from functioning well to functioning very well, with the flows improving further,
the lactate dropped further and that liver again ultimately went on to be transplanted and and
functioned well without any problems that could have been related to impaired perfusion of one lobe.
And then the final case I'm going to present this was a 51 year old. This was a liver from a 51 year old DCD donor,
so poor quality donor who had a very large fatty liver that had been declined for transplant by all centres in the UK.
So this was then offered up nationally for research,
and the group in Birmingham had a research study going on where they could put these livers on the on the machine.
So we travelled up there with the machine and put this liver on,
and this was a fatty liver that had been on ice for eight hours by the time we got to it.
And this is why we went on the machine and it perfused, nice and homogeneously after one minute.
As you'd expect, it was very acidic, with only 200 meals a minute through the through the artery.
And, you know, looked not very good. By one hour, the arterial flows had improved a bit.
That should come come up of its own accord, but it still wasn't a great liver by two hours.
The flows were still a right that was improving further. The liver had started to produce bile at six miles an hour and was starting to look better.
And then by four and a half hours, the flows were better still. That was better still bile.
And. Should it continue to improve and it was now using glucose, so the glucose a drop from 20 to 11 MetaMaus.
So the team went on to transplant that liver and again,
that liver function well after after transplantation and is still functioning well two years later.
So in summary, from the clinical studies we've done,
we've shown that normal perfusion is associated with less early graft injury after transplantation,
and this is despite higher organ utilisation in the normal thermic groups and substantially longer preservation times.
And we've also shown that it appears to be the case that we can use normal perfusion to assess organ quality to help guide clinical decision making.
And these findings have gone on to be published recently in Nature.
I'm now going to hand over to my colleague Colin. Thank you very much, David.
And so, as you've already heard, machine provisions been implemented successfully in the clinical context.
But one key thing that I was looking to investigate was whether you could recondition
organs and improve organs or organs that may be and weren't functioning.
Could you actually further enhance them? And fatty livers, as we've heard, do particularly poorly when transplanted.
These are a very good type of organ to try and reconditioned and enhance.
So why did fatty livers do so badly and fatty liver basically when it was transplanted?
And if there's more than 30 percent of large fat droplets, as you can see,
the white circles here within the liver that's been shown to decrease post-transplant survival by up to 70 percent.
And this is largely attributable to ischaemia reperfusion injury.
So these livers have a much more exuberant inflammatory response increased neutrophil infiltration,
reduced ATP production, mitochondrial dysfunction and impaired blood blood flow, which lead to these poor outcomes.
And as a result, a large number of these livers are discarded and a thousand fatty liver is in the states are discarded each year.
That's in the context of 6000 transplants a year in the UK.
Half of all discarded livers are due to stay at horses. So it's a big problem.
The problems made worse by fat donors, which are increasing.
So obesity is a risk factor for fatty liver disease, and no quarter of donors in the UK are clinically obese.
So in the context of not enough organs available for transplantation, we try and optimise the ones that are available to us.
So as David's already presented us and the clinical trial,
we looked at a subset subset of fatty livers that were transplanted and matched them to lean livers that were all normal, famiglie, perfused.
And what you can see here is fatty livers, unsurprisingly,
mobilise more fat into the circuit during preservation and also have more fatty acid oxidation and as measured by three hydroxybutyrate.
But if we looked at the degree of state forces over the preservation, unlike what had been shown in animal models,
actually the total amount of fat before preservation, after preservation and after reperfusion remained largely unchanged.
But if you compare the post-transplant outcomes in these livers from a state Typekit compared to lean liver,
actually the still toxic liver has had more preservation injury in terms of Peaks University than their lean counterparts.
So the question is, can we get these livers to perform as well as these livers by enhancing them during preservation in order to do this,
a brief understanding of liver fat metabolism and was important for me anyway.
And so the liver gets fat from various sources, from diet, from a mobilisation of subcutaneous fat or visceral fat, as known as terrified fatty acids.
And these all contribute to the fatty acid pool within the liver, as well as de novo life of genesis within the liver.
They can either be stored or follow two pathways either oxidation.
So that's via beta and beta.
Tradition into mitochondria are very low density lipoprotein and secretion is a certification which then gets restored again peripherally.
But actually in the ex H2 circuit, there's no diet, there's no subcutaneous fat and there's no visceral fat.
So the only source of fat within the liver is the normal life biogenesis pathway.
So this is where the liver makes fat from non-living precursors, mostly glucose and the end product as palmitic acid or palmitate.
And this process is stimulated by insulin. So basically, I took all livers that were discarded because of steatosis.
All seven UK transplant centre said, No, it's too fatty. We don't want to transplant it.
They came to Oxford, recalculated and perfused on the circuit.
Labelled water was added, and this allows us to quantify newly synthesised fatty acids via gas chromatography.
Mass spectroscopy and livers were perfused for 48 hours, with frequent gas sampling, perfusion analysis and 12 hour leak or biopsies.
So a total of 21 livers were taken during this period. Three were excluded as they didn't demonstrate any any evidence of function.
So this allowed 18 40 hour perfusion.
Six livers were perfused on the machine by itself, six levels with an perfused on the machine with the addition of this LDL apheresis filter.
So these are filters are used in patients with very high cholesterol that's refractory to medical
treatment and essentially mechanically filters out lipoproteins in the final group as well as a filter.
We added some drugs.
So for school and increases, it's tariffication and v LDL secretion L-carnitine and shifts to fatty acids to the mitochondria for beta oxidation.
And then we tried to reduce the normal life of Genesis by reducing the amount of insulin and glucose that were delivered to the liver.
This is my wife and her. I think I was able to confirm.
Her coming in at 3:00 a.m. Saturday morning to the spending quality time together, and it paid just about to save the relationship.
So if you look at the demographics of the lovers, there were six in each group and actually they were quite similar.
And there were four DVDs and two decades within each group. And and yeah, they were otherwise well matched.
The cold ischaemia times were up in the region of around 12 hours of news lovers of a UK tour before they finally made it to Oxford.
And so that that you actually had quite a lot of injury already sustained before they arrived.
If we look at the basic function in terms of page normalisation, lactate clearance and glucose metabolism, the liver performed in a similar way.
And this is important in the context of comparing metabolic function that their baseline function was quite similar.
Unsurprisingly, the glucose of the third intervention group was lower, which is what we targeted.
Looking at, the elite transmitted and the perfused itself actually all increases, but only increased significantly significantly.
In Group one, there are new interventions.
The baseline A.L.S. level is a reflection on the amount of energy it is already being sustained in the liver at any ongoing enzyme releases,
probably reflective of ongoing injury. So that seems to have been attenuated in the second two groups compared to the first
hepatic arterial flow was also significantly higher in our intervention groups,
potentially here. Reversing the impaired sinusoidal blood flow that is no one's occurrence did talk to Glovers and an end and PLO,
and indeed there was a reduction in arterial flow during preservation. Porterville remained unchanged in the groups by adding this filter.
We were successful in mechanically removing triglyceride from the circuit,
and this in theory could reduce the amount of Lypertek scarcity, which has also been shown to impair liver function.
The same was true for cholesterol, and we also show a shift in fatty acid partitioning when L-carnitine was added towards
the oxidation pathway to those fatty acids rather than being stored or being oxidised.
So how does this actually result in the amount of fat within the liver?
And by measuring the biochemically,
then by homogenising the liver tissue and measuring the triglyceride was a slight increase in the livers and employment group,
actually a 45 percent reduction in our treatment group.
And I suppose the change was significant compared to the slight increase. Here you can see, I'm not sure if you can see it very well,
but lots of large lipid droplets at time zero and have more or less either become very, very small or disappeared by 48 hours.
And this was actually associated with a significant reduction 48 hours and the amount of daily fatty acids, namely palmitate.
So this is by reducing glucose and insulin, we actually reduced to normal for Genesis,
and that probably accounts for the reduction of fat within the liver.
So to conclude, there's demonstrate that we can successfully manipulate hepatic metabolism and excite you.
Setting the addition of the Selter improves function of the liver, but don't change them at a site within the liver.
However, by adding L-carnitine, altering insulin and glucose and function,
improved fatty acid oxidation increased and there was a reduction in de novo Lt. Gen. Terrestres actually moving on from using the device.
As it is, there's potential to exploit things even further to try and transplant even more livers with with good outcomes.
I know that Prof. Who's going to wrap this up? Thank you very much.
So really,
just just to finish on this theme of using normal thermic perfusion as a platform to treat a liver rather than simply a means of preserve the liver.
This is clearly an opportunity, and it's an opportunity which has been more or less not exploited so far.
It's very exciting. We could give drugs. We just heard Carlos excellent work looking at approaches to reduce the fat content of livers.
There are other drugs which we can use, which will mitigate the effects of the inflammatory effects of ischaemia reperfusion.
There's some very nice work just beginning to emerge using nanoparticle technology to deliver drugs to endothelium.
There was a lot of interest in the use of cell therapy imaging kind of stem cells,
which have natural and anti-inflammatory properties, regulatory T cells, which which reduce the immediate necessity of an organ.
And gene therapy there is there is evidence experimentally of giving, for example, IL 10 as a gene therapy to reduce the inflammation in a graft.
This experience of giving CTLA four IgG, which is one of the immunomodulators to make the organ less likely to reject these, are just some examples.
Many of these have been done in clinical practise. Yet these are all experimental studies.
They're all waiting to be done, and there are many, many more. That's just a few as it were picked out of the literature.
This is this is this is an illustration of why normal seeming perfusion might enable this.
It doesn't matter which gene was being used as it happens,
it was an oligonucleotide caught in reverse and which is a strategy which might prevent hepatitis C re-infection of livers.
That doesn't matter. What's important is in the graph, which shows just how much more effectively the gene is delivers enormous,
I think, a warm fusion environment compared to cold storage.
So is this going to change the future? Is it going to change how we look at organ preservation?
Is organ preservation going to become a much more active process than it currently is?
One might envisage a time in the future where organ donation of course still happens,
where it happens in hospitals, all over the country, all over the world.
And if the organs are completely straightforward, there's no reason perhaps why they shouldn't be simply transferred to transplant.
Hospitals in transplant is pretty much as they are now.
But what about delivering the high risk organs to specialist reconditioning centres where the organs are placed on perfusion devices?
They're assessed, and depending on that assessment, they may be treated with interventions as yet unspecified and then tested again.
If they pass the criteria, they then get transferred for transplantation.
And if they don't, they're discarded or more likely used for research.
Well, that all sounds like quite an exciting possibility for the future.
Of course, the future is often a lot closer than we think.
This is a small organisation as a small company called Lung Bioengineering, based in Maryland in Silver Spring,
Maryland, this building has been built with the express and sole purpose of reconditioning lungs for transplantation.
So lungs which fail to meet the criteria for lung transplantation are flown into this institution
that put on a machine that treated if they if the gas exchange and other parameters improve,
they're taken off the machine and sent out somewhere to be transplanted.
So this is perhaps the vision of the future. And is this perhaps a new science?
Is this a new and new set? Of course, this is going to evolve in perhaps the same way that tissue typing did in the 1960s and 1970s.
It remains to be seen, but it would seem to me a very likely possibility.
And remember, what we're dealing with at the moment is essentially first generation to.
Mythology, we all know what happens to technology. Thank you very much indeed for your attention.
Very happy to take any questions, as are the others.