Good day, everyone, and thank you very much for attending this lecture. Today, we are going to cover liver tumours and liver lobectomy in dogs. So, the most common indication by far for doing a liver lobectomy is because of a liver tumour, and there are 4 histologic categories of liver tumours in in dogs.
There is the hepatocellular type of tumour that can either be a carcinoma or an adenoma. And by far, this is the most common tumour and it is by far mostly the malignant type, meaning the carcinoma. You can also have tumours that are from the biliary system, so they can be bile duct in origin.
They can also be neuroendocrine, which will be referred to as carcinoids. And they can also be from a sinomal origin, which these tumours will be called sarcomas. But as I mentioned, by far the most common one is the hepatocellular carcinoma and therefore we will concentrate on this particular tumour today.
There are 3 types of morphology. It can either be massive, nodular, or diffuse. The most common type that we see is the massive and therefore this tumour is gonna be referred to as massive hepatocellular carcinoma.
They account for about 53 to 84% of the tumours in dogs. They have a relatively low metastatic rate from 0 to 37%. And they most often will affect the liver lobes on the left side.
And we're gonna talk more about the different divisions of the liver and also the prognostic significance. But just very briefly, this is good news because tumours on the left side are easier to remove and they have a better prognosis. So, in terms of survival.
So therefore, this is good that the majority of tumours are on the left side. The diffuse or nodular are less common and they are more aggressive. They have a high metastatic rate of 93 to 100% and they metastasize to the regional lymph node, peritoneum, lung, heart, kidney, among other organs.
The diagnosis, when we are presented with a dog with a hepatocellular carcinoma, the clinical signs tend to be very non-specific, hyperexia to anorexia. They can have weight loss, but it can also have weight gain and that the tumour can grow to be very large and that in itself can account for the weight gain. And I'm sorry.
In some cases, they can also accumulate some ascites, which is not very common, but if they do, then, then, then that can also be another source of weight gain. They can be lethargic. And there can be vomiting.
So as you can see, very non-specific. On physical examination, there might be some abdominal distention, but not always. You might be able to feel a cranial abdominal mass, but it has to be relatively large and there might be res, but that turns out to be uncommon and ascites as well is quite uncommon.
On blood work, again, On the CBC, nothing that is pathonemonic by any means. You can see a mild to non-regenerative anaemia. You can also see some thrombocytosis in some cases.
And on the chemistry panel, you can see in some elevation in the liver enzymes, but I think it's very important to note that it is not always present and therefore, an absence of elevation of liver enzymes does not rule out liver tumour. And I think this is a very important point. We will see routinely dogs with very large masses and their liver enzymes on the chemistry panel are completely normal.
So, although the blood work might be indicating that there's something going on in the liver, again, an absence of changes does not rule out liver disease, namely liver tumour in this case. So once we are suspicious or we know that there's a liver tumour or liver mass, we are justified to stage the patient. And we, in this instance, we should always do chest imaging, and that can either be with radiographs or it can be with CT, so on CT, it is more sensitive.
It can detect nodules that are smaller than what radiographs can detect. But radiographs still remain an excellent way of imaging the chest and certainly easier and cheaper than doing it by CT. We also want to image the liver to have a better idea of where the mass is and what is involved, and that can be done with either ultrasound, CT with an angiogram, or MRI.
Ultrasound is made arguably the test, the imaging test that is done most commonly. By comparison to CT and MRI, easier, and, we still learn a great deal of information with ultrasound. So it is a great imaging test.
However, CT, particularly with angiogram and MRI, I think that we certainly learn more and have a better imaging of the liver. So, not that every case will necessarily need a CT or MRI, but I think that CT angiogram is very helpful for cases that have tumours on the right side. If you don't know which side the tumour is on, or if it is a case of recurrence, then I think the CT is a superior imaging modality than the ultrasound.
Sometimes, the tumour is gonna be so large on on imaging that it can actually be difficult to tell where it's originating from on ultrasound. And CT may be better at telling us where the tumour is originating from and what is involved. Although CT is not an IBL test, as a matter of fact, there are no anal be all tests for imaging.
There There are still questions that will not be answered when we do imaging for large tumours, particularly on the right side, but it certainly is we learn a lot and very much helpful in planning the surgery and helping the owners decide if they want to go to surgery or not. In order to make a diagnosis, so the imaging is great in telling us there's a mass, what is involved, how big it is, but it doesn't necessarily tell us what it is, particularly when they're smaller, I think very large mass, as you can tell, the, the name says massive hepatocellular carcinoma. So when we see very large masses.
I don't know that I've ever seen anything that different than the hepatocellular carcinoma. But for smaller masses, I think there's a, a, a, a number of differentials and that does not necessarily mean that hepatic mass is always gonna be neoplastic for that matter. So, we can try to get a diagnosis before going to surgery and removing it, and that can be accomplished either with ultrasound, aspiration, or ultrasound-guided, I should say, aspiration, so final aspirate, or a true-cut biopsy.
Unfortunately, these tests are not incredibly reliable. But before we do, I think it's good to do a basic blood work and a coagulation panel prior so that we know what is the risk of haemorrhage and bleeding. The risk is about 5% for these tests.
With an aspirate that will lead to cytology, the accuracy of knowing what the diagnosis is is only 30%. However, our question is, is this neoplasia, and, depending on the studies that you look at, the sensitivity was 14 to 52% to tell us if it's neoplasia. So not great.
However, if you do have a diagnosis of neoplasia, then you can be pretty certain that it is because the positive predictive value for neoplasia is 87%. So at least we know that if we get an answer of this is neoplastic, we can believe it with a pretty good deal of confidence. However, if it is not neoplastic on the aspirrate, then we certainly have not ruled it out.
Most clinical pathologists feel that it's difficult to determine if it's malignant versus benign, but again, in dogs, the majority of tumours are going to be malignant and therefore, I think that we, once we get a diagnosis of neoplasia, we should just assume that it's malignant. A core biopsy is accurate in about 70% for neoplasia, so, probably better, but not great by any means, but I, I think that it's a good test. The downside is that with the core biopsy, this leads to histopathology.
Which takes a little bit longer to get our results back. The treatment of choice for these tumours is surgical excision. And there will be, as you will see, different ways of being able to excise these liver masses.
In preparation for the surgery, we want to do blood type or crossmatch, and we want to be prepared for a blood transfusion. It is one of the most common convocation of, liver lobectomy is, blood loss, and we should be prepared to replace the blood loss, with a transfusion. We also want to do coagulation tests if they haven't not been done recently before with the PT and PTT, the liver is responsible for producing the coagulation factors, so we wanna make sure that the, the liver is still able to produce enough coagulation factors.
And then also in preparation for the surgery, we want to clip very wide, wider than what you think you're gonna need. We wanna be prepared to extend the incision, should we need to, and particularly on the right side. We definitely want to be better prepared for right-sided tumours.
So be prepared that you might wanna do a median sternotomy, so clip more cranial than what you would think. And then you can also do a periccostal approach again, particularly for right-sided tumours. And so that means that you want to clip on the lateral aspect, where you go very dorsal so that you are prepared to do another incision should it be needed for your approach.
Per operative antibiotics and then, dorsal recumbency and we're gonna do a ventral midline laparotomy. Surgical excision, as I've mentioned a bit earlier, is the treatment of choice. There is a 40% intraoperative mortality for tumours of the right division, and we're going to very shortly talk about and show what the different divisions of the liver are.
And in that particular particular study, the left division was 0%, so none of the dogs died intraoperatively when the tumour was in the left division, but again 40% on the right side. I think that it's and it's typically due to haemorrhage. So again, we're going to show you why the right side is more challenging and more susceptible to haemorrhage.
I think that it's probably fair to say that. As you can see, this paper was published in 2004, and so when the data was collected, it was early 2000s and cases when you read the materials and methods cases that were collected went back into the 1990s. So we are now in 2021.
I think it's fair to say that our profession as a whole made some great improvements. Our anaesthesia is better, our critical care is better, and even we surgeons are better. There's been a number of publications that have come out about the anatomy of the blood vessels and the liver and so on.
So that I think that as a profession, we are better at dealing with these tumours, and I, I think that the intraoperative mortality on the right side is lower than 40%. But in all fairness, I do not have a data or some data to support this and therefore this is speculation on my part. So, here is the liver.
And as I mentioned, there are 3 divisions to the liver. There is what we call the left division, the right division, and then the central division. So, the left division is going to be the left lateral lobe.
And the left medial lobe. The central division is going to be the quadrate lobe and the right medial lobe, and the right division is going to be the right lateral and the caudate lobe with the caudate process. There is the papillary process of the caudate liver lobe.
From a, anatomical perspective, the parenchyma is attached to the caudate, process of the caudate liver lobe and so therefore, the anatomically it is considered as part of the caudate lobe. However, as you will see, the blood vessels that go and come out of the papillary process, typically glow on the left side. And therefore, from a vascular perspective, it can be thought of more as a left-sided lobe, but you still have to deal with the attachment of the pareya.
So the reason why the right side has a greater risk of complications is because of its relationship to the major vessels and particularly the vena cava. So I think that this drawing illustrates well that the liver parenchyma is in very close association with the vena cava and in some cases, Even wraps around the vena cava. And then there's also the portal vein, which typically is not as much of a.
Of the issue in terms of anatomically and the relationship there typically is room between the liver parenchyma and the portal vein and therefore there's more the vena kiva that's going to be a challenge. And then there's also the arterial system and then the common bile duct coming from the gallbladder also, will go towards the right side. Again, typically there's room, but, you know, certainly for tumours that are very large and, and that are growing and have an extension medially.
The common bile duct and the portal vein, become more of an issue, whereas because of the distance between the left side and the structures, that is rarely an issue with tumours on the left side. So for all of these reasons, the liver lobectomy. For right divisional tumours is more challenging and and can lead to haemorrhage, blood loss, and as I've mentioned a little bit earlier, death in some cases.
So, on the left side is a cast of all of the blood vessels in the liver, and it certainly is, as you can tell, a highly vascularized, organ. However, we don't need to, be preoccupied by all of these vessels. The ones that we really need to pay attention to for liver lobectomy are the vena cava, the hepatic branches, hepatic.
Veins that is, the portal vein and then the branches of the portal vein. So on the right side, the grey vessels are, well, it's the portal vein with the different branches. And then we have the vena cava on slightly to the left, and then with all of the hepatic branches or hepatic veins, I should say, going into the vena cava.
So we're gonna look at this anatomy a little bit more closely so that we can appreciate the the the vessels and the vascular anatomy. So on the portal vein . There are two different studies that have looked at the vascular anatomy.
There's a paper by Hall in 2015 and by Marie in 2015 as well. And although the, the anatomy is, you know, slightly different, I think the the main points, the main branches are for all practical purposes the same as we would expect. So we have the portal veins, so I'm going to take the hall description first.
And then, very soon after we get into the close to the liver, you're gonna see the branch to the right. And so that's the right divisional branch. And also the Marie paper, you can see there is the right portal branch as well, which then will go to the caudate right lateral dorsal and right lateral ventral as well.
So that's the right branch. And then as we continue, there's going to be in this instance a central portal vein, portal branch that's described. Whereas in the Murray paper, it, they, they describe it as being the left portal branch, then which then sends a branch to the right medial.
And then as you can see, the papillary branches are coming off of the left side. And it's very similar in the hall description where the papillary process receives the portal blood from the left. And then you have a branch going to the quadrate or multiple branches going to the quadrate lobe, and then branches going to the left side, meaning left medial and then left lateral.
And this is very similar here, branch to the left medial and then left lateral ventral and left lateral dorsal. So very similar with, you know, a little bit of differences and how it's been described, but for all practical purposes, we, this is what the portal vein, looks like. If we go on the vena cava side, so the The diagram on the left is a typical view of the surgeon where the dog is in dorsal recumbency, the top is cranial, and the bottom is caudal.
And on the right side of the screen, it is the left side of the dog because the dog is in dorsal recumbency. And so we can see that we have the caudal vena cava going and remember that the liver prankima will typically be superimposed and maybe surrounding the vena cava. And then you're gonna have some branches coming from the caudate and the right lateral, and then there's gonna be the right medial, there's the dorsal right medial.
And then there's ventral right medial. That will join with the quadrate and have a branch going in here. And if we contrast this with the other diagram, the other diagram is a different perspective.
It's, it's looked at from the diaphragmatic side. And so therefore, the top of the vena cava is caudal and then the, the light grey opening that is what will be continuing towards the heart. So, as you can see from the left diagram, the quadrate and the ventral right medial come together and they form a branch hepatic vein that goes into the vena cava, or, some people will refer to the branch here as the left.
In this instance, they called it the main hepatic vein. And the main hepatic vein will receive the middle hepatic vein, which is really a combination of the right medial and the quadrate. And then, whereas they called this the dorsal and the other study here, they call it the accessory right medial.
So there's accessory right medial, then there is the middle hepatic which goes into the main hepatic vein. The main hepatic vein also receives blood from the left hepatic vein and then you're also gonna have the papillary process here that goes more towards the left side as shown over here, and then obviously the left lobes that will come together to form the left hepatic vein. So this is the hepatic veins.
Coming together and then how they go into the vena cava. But what you don't really appreciate is the, the fact that on the left side, the liver lobes have a nice hylu, which is not the case on the right side, and this makes a big difference. And it, it also relates to the fact that the pa on the left side is not intimate with the vena cava, which is what it is on the right side.
So this is where I just flip things around so that for the diagram on the left so that it would have the similar perspective as the one on the right, meaning that at the top of the screen. Caddle and then the more bottom of the screen is going cranial and so you can see how the two are quite similar maybe with different names, but very similar in terms of how the branches come together. So here again, we show how the left side has a comes more on the high list, whereas the right side, not so much and very intimate with the vena cava again, which is why it makes it more challenging because the parenchyma is very intimate with the vena cava, then you don't see the branches, the hepatic veins.
On the right side, which makes it very challenging to know, where that you need to ligate, for example, and, and therefore more, more chances of having significant blood loss. So, here, good example again, vena cava, my mouth is showing the vena cava. There is, this is the caudate liver lobe, and we have the ligament, hepatos renal ligament.
And so you can see that the liver on the right side covers the vena cava and in some dogs even surrounds the vena cava. And we have the portal vein over here, which is a certain distance. But again, if you had a very large mass, that relationship could be very different as well.
So, here, we have the diaphragm at the top of the picture. And on my, in my right hand, I have the right right medial liver lobe. And I'm taking the right medial liver lobe and I'm pushing it towards the left of the dog.
So the dog is in dorsal recumbency and we see this little branch here that is the accessory right medial, or at least the one of the branch that goes directly into the vena cava, more on the right side. And then over here in my left hand, we have the right lateral liver lobe. And then what we're gonna do is that we're gonna open up the vena cava and we're gonna see the branches from the inside and have a better appreciation again of the hepatic veins on the right side.
So here we have the diaphragm at the left of the screen and the vena cava has been opened. And the liver lobes have all been pushed towards what is the left side of the dog. Again, the dog is in dorsal recumbency.
So in here, I have an instrument that is going into the the main hepatic vein. When I was a resident, we would call this the left hepatic vein, but as I've shown you, the studies, at least one of them refers to this as being the main hepatic vein, which is a combination of the middle and the left hepatic veins coming together. Forms the main and then the main goes directly into the vena cava.
So very large vein that is present. And then now the instrument. I, is, in an opening that may be either the middle, maybe this dog is a middle that goes directly into the Vinicava it probably is also could be the The accessory, right medial that goes into the vena cava.
So there again, a, a, significant vessel going into the vena cava. But what I also want to point out is all the yellow arrows point to these small openings into the vena cava that are small little, small paddock branches that take the blood from the right side of the liver into the vena cava. So, as you can see, there are many of them, throughout the length of the vena cava that is intimate with the liver parenchyma.
And therefore, you can probably tell that it would be very easy when we dissect the parenchyma away to have these vessels bleed out. So I think this is a very good example of the fact that there can be a lot of smaller branches or hepatic veins that open directly into the vena cava. So, the technique for doing a liver lobectomy is that first, you want to cut the ligaments of the lobe that you're, you're going to remove.
On the left side, there are these ligaments with the the diaphragm. This shows the caudate lobe that has a Yeah ligament that goes towards the kidney and so we cut these ligaments so that we can free up the parenchyma and try to find an area that is narrower and on the left side, certainly, there is more of a hyless. If you need to improve the exposure, then there's a couple of ways that that can be done.
You can open the diaphragm, ventral to the vena cava, and then you put stay sutures in the diaphragm and you pull caudally. And what that does is it, it brings the liver more caudal away from the sternum and you have more room to work with. So this is a good little trick.
That allows you to bring the liver more caudally. Obviously, then you end up with, an open chest cavity, but that in itself is not, a reason not to do it. We can deal with it.
At the end, when the liver tumour is out, we close the diaphragm and remove the air. If another way of getting more exposure is to do a periccostal incision, this can be very helpful for very large tumours on the right side. We typically don't need to use these tricks for tumours on the left side, and so these are typically used for tumours on the right side.
So you can do a periccostal incision. You go along the 12th rib, starting at the medial or I'm sorry, starting at the cranial aspect of your midline incision, ventral midline incision, then you go along parallel to the 12th rib. And then you can also do a median sternotomy, at the caudal aspect of the sternum, and that will allow you to have a better exposure as well.
So these are different ways, to get better exposure for those very large tumours that are in your way, really, and, and difficult to go underneath the tumour, meaning the dorsal so that you can dissect. You, you can either do a partial or a complete lobectomy. When tumours are at the very arising from the edge, then it's easier to do a partial, but if the tumour grows into the, the bulk of the parenchyma, then oftentimes it's easier and safer to do a complete lobectomy.
There are different techniques to achieve this. You can do the TA stapler, which is, arguably one of the easiest and fastest. You can do the finger fracture with individual ligation, or you can clip or you can use the vessel sealing device after you've fractured the parenchyma with your fingers.
And then, that leaves the vessels. Intact that you again, either ligate, clip, or use a vessel sealing device. Instead of your finger, you can use the inner tube of the pull suction tip, and then you kinda use it to break down the prankima.
And so that's been referred to as to skeletonize the liver. And there again, the idea is that the, the bigger vessels are going to remain intact, and then you can address them with ligation, clip, or sealing device. If the area that you want to resect is not too thick, then, you can use the vessel sealing device, right away without having to, do finger fracture or no skeletonation.
And then you can do hylar dissection if the liver lobe, particularly those on the left side, have a very nice hy list and so that, that can be the easiest. Some things to consider is that the left lateral and the left medial lobes are sometimes easier to be removed on block. Some dogs, they share a, a lot of parenchyma at their highlu.
And so instead of being very well lobuated individually, the highlus is more of a common one for both of these liver lobes, so it's easier to remove both of them together. The same is true about the quadrate and the right medial liver lobes. Again, towards the cystic duct, they can share a lot of parenchyma.
They can be joined by a lot of parenchyma so that it's easier to remove the two of them together as well. And then when we are dealing with the central division, so again, that would be quadrate and right medial, then you want to pay close attention to the gallbladder, the cystic ducts, the cystic duct, that is a paddock ducts, and then the common bile duct. And so the, you would want to leave the cystic duct intact, if you're gonna preserve the gallbladder.
If you remove the gallbladder, then you're gonna ligate the cystic duct. And then if you want to preserve the, the common bile duct. Certainly, if you remove the gallbladder, then you must preserve the common bile duct.
If you were to sacrifice the common bile duct, then you have to, take the gallbladder and do something like a cholecystoduodenostomy or cholecystodigenostomy. A paddock ducts, you can't sacrifice a hepatic duct. Obviously, you cannot sacrifice all of them, but if you do sacrifice one, sometimes it's easy to cut a he paddock duck without knowing that you've done it.
And then, that can be the source of bio leakage. So you want to make sure that, . You are aware that you've cut a hepatic duct and that you ligate it if that's the case.
So, again, paying very close attention to these anatomic structures is very important. So, in this particular example, the ligature is being used. This is a left division tumour, as you can see, easy to take out, It is, the picture on the left, it is arising from the edge and so very easy to put the ligature across the liver rankima and just cut away using the ligature instrument.
Picture on the right shows how the pancreas can be in close association. So again, pay attention to these things, particularly on the left side, the left limb of the pancreas goes along the, the greater curvature and can form some adhesions with some of these larger tumours. So something to pay attention to again.
The TA stapling device, which stands for thoraccoabdominal, an instrument that is very commonly used, certainly makes a liver lobectomy very straightforward by comparison when you don't have one. There are different lengths of the, the cartridge, and so in this instance, it is what we would call a 55. It is 55 millimetres long.
You can have a 30 or a 90, and then there are different heights of staples. And So on the 30 TA stapler, you have what we call the V3 which stands for vascular 3 rows, and that would be the the cartridge of choice because it has 3 rows of staples instead of only 2, and the staple height is also Shorter, so that less likelihood of a vessel pulling out or bleeding through the staple. So the TH30V3 is the one that we will, that we prefer.
However, because it's only 30 millimetres, 3 centimetres long, sometimes that's not long enough. So sometimes we'll use two of them. That overlap.
Or if we go in bigger dogs and we try to do a partial liver lobectomy, then we'll go TA 55, so it's longer. In this instance, we'll use the blue cartridge, because the staple height is the shorter one between the two options. The other one is green, if I remember correctly.
And then, there's a TA90 as well, which we don't use very often, but in a very large dog that you wanted to do a partial liver lobectomy, and then obviously the liver, with is very considerable, then the TA90 can be helpful as well. So, you, again, can either do a liver partial lobectomy. As you can tell, there's a, a thickness that will fit, so if it's too thick, it will not be able to fit in there.
But you can go into a part of the liver that is thinner if that is appropriate, for where the tumour is. So here is a great example of a partial lobectomy liver lobe that is relatively flat. And so, the thickness of the liver is able to fit into the jaws of the cartridge.
And so very rapid way of doing a partial lobectomy. And then once the staples have been fired, then make sure it, it may sound silly, but make sure that you cut on the correct side of the cartridge. So you want the staples to stay with the dog and so you're going to cut.
Away from the cartridge so that this part here, I don't know, you can appreciate there's a little tumour in the hands of the surgeon, so you cut along the cartridge so that then the tip of the liver lobe can be removed. So the staples stay with the dog, they don't stay with the part of the liver lobe that's going to be removed. The Pringle manoeuvre is a manoeuvre done at surgery that can be very helpful if you have severe bleeding from the liver.
And you can't tell where it's coming from, then you can do the Pringle manoeuvre. What this is is that you're gonna put your finger in the area of the epiloic foramen. So we have the portal vein, we have the celiac artery which then will give the hepatic artery, and we have the vena cava.
And so, with your hand, you put your thumb at the dorsal aspects at the very bottom. And then typically your index finger, and then you're gonna squeeze all of these vessels between your two fingers, and that's the Pringle manoeuvre. So you will entrap in your hand, the portal vein, celiac artery, and the vena cava.
And it will not stop the bleeding completely because the bleeding, the blood is also coming from the other side, meaning like the hepatic veins and so it's, it's kind of a bleeding backwards, if I can say it that way. But it can certainly slow down the bleeding, a whole lot to where you're able to see where it's coming from and hopefully be able to address the tear or where it's coming from. So that the, you can stop the bleeding.
So Pringle manoeuvre can be very helpful when there is severe hepatic bleeding. How much of the liver can be removed. So that magic number is that you can remove 70% of the liver acutely, provided that the rest of the liver is normal.
And this is unpublished data that shows what volume each liver is, accounts for, liver lobe, that is. And so, The caudate process of the caudate liver lobe is 8%, the right lateral is 15%, right medial is 12, quadrate is 10%, left medial 15. The left lateral, 32.
So as you can see, the left lateral is a very significant, a third of the liver parenchyma is from the left lateral. And then the papillary process 8% as well. So that gives you an idea of how much of the liver, well, you know that 70%, but if you're trying to figure out at surgery, how much of the liver you're removing, then this gives you a very good idea of what percent each liver lobe accounts for.
Other surgical or treatment options, there has been some publications on microwave ablation, for the liver. And this we would reserve for small nodules. And that is very convenient for metastasis where we don't want to remove.
If there are nodules involving multiple liver lobes. And you say, well, I can't remove all of them because this is not compatible with life, then you can go and microwave ablate these nodules. And again, so, maybe the best indication is for metastasis.
There are two papers that have been published where they report the use of microwave fibrillation. In this particular paper was reported for lesions that were 0.5 to 2.5 in diameter.
There were 5 of them in total. They were either biliary adenocarcinoma, hemangiosarcoma, a patocellular carcinoma, apocrine gland adenocarcinoma, so this was metastatic. .
So this paper reports the safety and it appears to be safe, but there is no outcome that is well documented. So more of a safety measure or report. And then this particular paper was used with laparoscopy in two dogs.
One dog had hepatocellular carcinoma, 4 centimetre in diameter, and, the dog was doing well 220 months post the procedure. And then the other dog had metastatic hemangiosarcoma. There were two masses.
They were 3 and 2.3 centimetre in diameter. The dog died 7 days post-op.
Metastatic hemangiosarcoma is a terrible disease and so I don't think that we can make much of a conclusion with such a terrible disease other than it can be used, but we don't know what really was the efficacy in this particular case. But microwave ablation, I think that as a profession, we're gonna learn more and maybe become a part of our arsenal, particularly for dogs that have multiple modules in multiple liver lobes. Are there any other therapy?
Well, I'll be very straight with you. Surgery is by far the best, treatment. And so these other therapies are really reserved for either people that don't want to go to surgery or dogs that have very risky procedures that again would go along with people that don't want to go to surgery or non-resectable lesions.
So chemotherapy, gemcitabine has been reported in 18 dogs. They were in 18 dogs, yeah, 15 of them completed all 5 cycles of gemcitabine. Median survival was 983 days and the median progression free interval was 971 days.
So very interesting. As I will show you in a little bit, in the Dr. Liptak's paper 2004, dogs that did not have surgery were not treated.
Their median survival was 270 days, 9 months. And so that would suggest that gemcitabine may have an effect, but very few dogs and I think that we need more data, but it, it certainly is something to consider. Radiation therapy has also been reported, 6 to 10 greys per fraction for a total of 18 to 42 greys, 1 to 2 fractions per week.
For a total of 3 to 7 fractions. The median follow-up time was 534 days, and out of the 6, yeah, out of the 6 dogs, 5 dogs had an objective response that was observed, but one dog also has had radiation-induced liver disease. I think that radiation therapy has a place, particularly stereotactic, but we don't have a lot of data.
And we certainly need to learn more before we can recommend this with confidence. But again, it certainly is an alternative for a dog that has a tumour that is not compatible with surgery. Intraarterial therapies, you can, again, for cases that have non-resectable masses or are poor surgical candidates.
Owners don't want to go to surgery. Another option, these are what we call transarterial and so a catheter is placed into the arterial system, oftentimes through the femoral artery. And then with interventional radiology, the tip of the catheter is directed into the, the arterial branch that is the most specific for feeding the tumour.
And and so this can be transarterial embolization to where you're gonna block the artery and then the idea is that you cut off the blood supply. It can be transarterial chemotherapy. So we're gonna deliver the chemo drug such that it's going to have a much higher concentration, in the liver than if it were given intravenously.
Through a peripheral vein. And then, probably what is done most commonly, is the transarterial chemo embolization where you do both chemo and embolize, in the same patient. So, to my knowledge, no study yet.
But I think that the, the patients that may do the best are the ones that have a small tumour. And unfortunately, these are the ones that we can also probably address surgically, whereas the ones with very large tumours may not respond as well. And so, unfortunately, what might work best for these intraarterial therapies are maybe candidates that are would be good for surgery.
But certainly, if you had a small tumour but was very intimate with the vena cava, for example, and surgery was gonna be dicey, this may be a very good alternative. The prognosis, so, with surgical treatment for the majority of dogs that have a hepato massive hepatocellular carcinoma, the prognosis is excellent. So in the doctor Lipak's paper, the median survival was not reached.
Therefore, it was over about 1500 days. And as I mentioned a bit earlier, dogs that did not have surgery, their median survival was 270 days, so a big difference. So surgical treatment can have an excellent prognosis.
As we've talked about these dogs, with massive hepatocellular carcinoma, the metastatic rate is relatively low. And so if you could remove it, then, as this study would suggest, A lot of these dogs will be cured. The side of the liver being involved, we mentioned that tumours on the right side have a 40% mortality rate based on Doctor Liptak's paper.
However, If you survive, then there was no difference between right-sided and left sided tumours. Dogs that have an elevation in ALT and AST on their blood work, when those were increased, they had a worse prognosis for survival. And in this particular study, the LiPA study, the status of the margins, meaning complete versus incomplete, was not prognostic for how long you live.
That is in contrast to another study that was published in the New Zealand vet journal with 37 dogs. There were 25 dogs where the margins were complete, and out of those 25, 3 had a recurrence. And then 12 dogs had incomplete margins and 7 of these dogs had recurrence.
The progression free survival was 1000 days for dogs with complete margins, whereas it was only 521 days for incomplete margins. And the overall survival was over 1800 days, which goes along with the the survival in the Liptak paper, so, you know, close to 1500 days. For complete margins.
However, for incomplete margins, it was only 755 days in in this particular study, which again contrasts with the Liptak paper. So, of course, as a surgeon, you always want to have complete margins. But there is some discrepancy in the literature as to what the significance is with respect to survival, if you have complete or incomplete margins.
So this is it. Thank you very much and certainly looking forward to seeing you in person when this is all over. Thank you very much.
Goodbye.