Dr. Culp: I kind of think like, what's the point where this is going to actually improve their day-to-day quality of life? That even if there's a complication that made it worth it to try.
Dr. Venable: Welcome to the Veterinary Cancer Pioneers Podcast, the show where we delve into the groundbreaking work of veterinary professionals who are dedicated to advancing the field of veterinary oncology. I'm your host, Dr. Rachel Venable, and I'm thrilled to embark on this journey with you.
Dr. Venable: Hello and welcome to the Veterinary Cancer Pioneers podcast. I'm your host, Dr. Rachel Venable, and today we're going to learn more about interventional radiology and the different testing and treatments that are available for our veterinary patients. And so I'm so excited today to introduce our guest, Dr. William Culp. Dr. Culp is a veterinary surgeon. He's a graduate of the University of Pennsylvania. He also did a surgical fellowship at Colorado State University and Interventional Radiology and Endoscopy fellowship at the Animal Medical Center in New York City. He's currently a professor of soft tissue surgery at UC Davis, and he focuses on surgical oncology and interventional radiology. Dr. Culp, thank you so much for being our guest today.
Dr. Culp: Oh, thank you so much for having me. I really appreciate it. I'm excited to be here and chat with you. And yeah, I very much appreciate the invite. Thanks so much.
Dr. Venable: Well thank you. And you know, when we get started, it's always kind of nice just to hear a little bit of background. And so what got you into veterinary medicine but then also surgery.
Dr. Culp: I am kind of one of the classic cases of like a little kid that wants to be a veterinarian. And then it just turned out really well that way. So I was lucky. I actually started working at a kennel when I was 11, and it was a kennel of almost all golden retrievers. So kind of a best-case scenario, although I guess down the road it's, a little bit funny that I ended up going into oncology, I guess, along those lines.
But yeah, definitely fell in love with animals and kind of working with them. And then from there kind of was focused on medicine going out from there. So it turned out well. I enjoyed growing up doing that and then was lucky enough to get into vet school. So it all turned out well. That way. And then from there, honestly, I just had great mentors during my veterinary school time and met a lot of really amazing people and didn't really even know specialties existed when I started in veterinary school.
So that was a new thing to me. But then once I heard about them and and got to experience surgery, I felt like maybe that was a good route to go and something I might enjoy. And thankfully that did turn out to be the case. So yeah, I'd say a lot of it I owe to my mentors and people I met along the way. That kind of gave me good advice and also just kind of introduced me to the different specialties. So I was lucky that way.
Dr. Venable: And what made you pursue fellowships? Because, you know, just doing a residency is so much more. And then a fellowship and you did two and both in great programs. So what got you into going that route?
Dr. Culp: Yeah, I again, it was something where it was nice because it wasn't something we heard a ton about during our residency, but I learned about it, spoken to some of my mentors, and I was always very interested in oncology and had more of a soft tissue focus. And so from there, you know, just some life experiences, too. And being exposed to cancer in real life. And I think that was a way of kind of opening my eyes to it as well. And then I knew that I wanted to do surgery and thought that maybe I'd want to do it in more of a specific fashion. So it was a kind of a slow burn from that standpoint of a progressive way of working my way through those different things. And thankfully, I enjoy it a lot. So I'm glad that it went in that direction. And yeah, I was lucky again that way.
Dr. Venable: Well, I think it was probably more than luck, I would have to say, getting into the top programs. Yeah, I think you're being quite humble, but it's it's really exciting, your background and what you can bring to veterinary medicine. And I know you've published a lot of different things. And I personally as a mentor, I'm quite interested in interventional radiology because I will be honest, I don't always know when to use it, and I know they've done it a ton in people. And we're looking at different options for dogs. So how would you say interventional radiology complements just surgical oncology?
Dr. Culp: Yeah, that's an awesome question. You know it's really cool air. And then, you know, even more specifically with what we're talking about is I o like the subspecialty of interventional oncology within interventional radiology is that it's one of the specialties where I feel like we're pretty close to human medicine in a lot of the things that we can offer, and the way that we're using it, there's certainly different disease processes and different focuses that we have. For instance, we do a lot more tumor stenting than they do in humans, just because that's pretty uncommon. But to the types of equipment we use, the types of procedures, the way that they're done in a minimally invasive fashion is pretty similar between humans and veterinary patients. So it's it's, interesting from that standpoint. And I think where it is now is that it's figuring out what of these options we should consider in our patients. What are the ones that actually improve quality of life, and then after that, actually prolong quality of life in a good way. And how those can complement, the other things that we offer, from my standpoint, having a focus on that and then being in a clinic where I'm able to offer that, we really do look at it as a fourth pillar of what we can offer for our oncology cases, on top of surgery, radiation therapy and, and the medical oncology techniques that that are available. So it's definitely something that comes up with our all of our conversations when we're thinking about the options that we can offer to patients. And I think, you know, a lot of where it came from in vet med was from the standpoint, well, we have nothing else in this particular situation that we can offer. Let's offer this because this is a new thing, and this is maybe something that can benefit. And I think that's where we were 20 to 25 years ago in vet med, where we were saying, okay, here's nothing else that we have to offer. How about we try this thing that's been out there and human medicine for a few years? And I think from there now we have more evidence and more ability to kind of think about the options that we have and maybe even offer things as a primary treatment in certain scenarios.
Dr. Venable: What would you see, like an example of a primary treatment, or what's the most common EOA therapy that you do?
Dr. Culp: Yeah, I think, you know, like generally speaking, when we think about the I-O techniques we have, I usually kind of categorize them into mostly into stenting techniques. And then usually vascular therapies are other types of things to like perk cutaneous therapies and tube placements and things like that. But most of what we do either falls into stenting or into vascular therapies. And I think that the ones that kind of stand out as the easy kind of like the low-hanging fruit, I think are the urethral stents. I think those are the ones where when you truly have an obstructed urethra and there's not really great options at the point of obstruction. Obviously, we have men on therapies and we have right on that we can consider in those situations. But when they're at the point of being obstructed, we don't have the greatest options. And so historically, when you think of those options being cystoscopy tubes, urinary catheters, those are great long-term options for a lot of owners. And so I think about something like urethral stenting and the success that's been had with that. And I think that that's a real advantage. I think that's a real step in the right direction. I think that's one of the ones that we consider most obviously it's not without fault. It's not without potential complications. There are definitely things that we have to think about when we consider placing a urethral stent. But for what it does and what we're hoping it can accomplish for that patient, it's really good at that.
It's really good at opening the urethra and letting them urinate, I think is one of the big steps forward from the stenting standpoint. And there are others there that we can talk about as well from the vascular side of things. The biggest one in our clinic where it's made a step forward is for prostate embolization. And so for our patients when they come in with prostatic tumors, we offer prostate embolization as a first-line therapy. And so we always recommend that they get chemotherapy afterwards as well. And we kind of talked to owners about approaching it from the standpoint of here's a local therapy. And then here's a systemic therapy. And we can likely use them in combination. And for most of our patients or owners at this point, that's what they oftentimes will choose. And so even in the subclinical cases, about 10% of our patients that come in for prostate normalizations have no clinical signs they come in because the tumors were found, incidentally, being worked up for something else. And so we'll still offer in those situations as well, because we've been encouraged by the outcomes and because the complications have been super uncommon. So for us, prostate embolization is a really, really common part of our offerings that we have for our cases.
Dr. Venable: Now that's really interesting. I've got a couple of questions. I'll start with the prostate part. So does it matter if it's invading into the urethra? Because you'll often it's hard for us to tell. Well, is this truly prosthetic carcinoma, or is it really urothelial carcinoma invading the prostate? Does that matter when it comes to embolization?
Dr. Culp: That is a great question. The truth is, I don't know. But what I think is, I'll just tell you, we're a little over 100 cases or so into doing it. We have some early data, but I see different categories. I see cases that are true prostate, and it doesn't look like it's anywhere else. They have no clinical signs or are truly subclinical. Then you see those cases that come in that are nearly obstructed. They have really bad lower urinary tract signs. And those are the ones that I'm always a little bit more cautious with prostate embolization on because I'm worried about potentially inflaming them and then having them obstruct. And then you have those cases where they have maybe minimal clinical signs, have an obvious prostate tumor, but then they also have a tumor that looks like it's extending into the bladder and away from the prostate itself. And what I will say is we still treat all of those when you look at with embolization, when you look at their, you know, the one thing that I get to see a little bit that we don't see just on the typical workup, is that I get to see the actual blood supply when we do their angiograms or direct to Angiograms.
And when you look at them, the blood supply to that region looks like it's affected outside the prostate. So the part of the urethra that's going towards the bladder, in the bladder looks like it shares the blood supply from these prostatic tumors. So whether it starts that way or whether it's parasitized, is it from the abnormal prostatic branches? I don't know, but the reason I mention that is because when we treat this is one of the embolization procedures we do where we have to be very, very specific. Because if you treat the prostate, you definitely have to avoid another major branch that's going to the bladder. And so when we treat these tumors, we want to treat all the branches that are going to the blood supply that's going to the prostate but avoid the main blood supply to the bladder. And I think that when we treat a lot of these cases, we are still treating the tumor from the prostate blood supply, even if it's in your reeds or and even extending into the bladder in a lot of cases, because I think the bladder itself has a separate normal blood supply in the majority of cases. I don't know yet what that means as for as long term, but I think that it means that we are probably getting some treatment. And so I think that if you look at outcomes and again, anecdotally speaking because we don't have all the data reviewed yet, it's uncommon for these cases to be euthanized for local disease. So I think it probably helps in a lot of those situations. Meaning I think that even if we see a tumor extending into the urethra and into the bladder, if we're able to normalize the prostate blood supply, I think that we're probably also treating a lot of that tumor extension as well.
Dr. Venable: Good. Well, good, because it's always so hard as the on to know which one it is. So that's great to hear that it doesn't necessarily matter and we're able to treat it. What are the parameters like if you know if I'm seeing a dog with with prostatic carcinoma, whether it's in the urethra or what have you, how do I know? Like, oh, this is a good case for ear it is that what are the parameters. Yeah.
Dr. Culp: I haven't truly treated nonprostate lower urinary tract tumors. So if we think it's a primary urethral tumor and like the prostate doesn't appear to be involved or we know it's a trigonal mass and there's no prostate or obviously in a female dog, those are cases that we haven't treated with embolization yet. We will offer inter-arterial chemotherapy. It's a lot for people to undergo. It's you know it's anesthetized procedure. It's expensive. It's a carotid approach. There's a lot involved in that. So most people don't like to go that route when the IV option is much more accessible and easy and straightforward and so I totally understand that. But we'll offer the intro tier chemo for those bladder urethral cases, and then prostatic embolization for those cases that truly have that start with the prostate tumor. And kind of go from there.
Dr. Venable: Can they have metastasis?
Dr. Culp: It's a good question I so yes, I have treated a few cases with meds. It's tough right? Because it's the conversation I always have with the owners. And you know this really well, and I try to keep it simple with them. I say like, I don't know which of these two things is going to be the life-threatening issue. First, most of the time with most of the diseases we treat, we worry that it's the the metastatic disease that's going to be the major issue. But one thing for the lower urinary tract tumors is that they may actually be the life limiting factor. First. And so I would offer it in a case motivated owners that understand the risks that also where the dog is demonstrating clinical signs. Because I do think that it would be something to consider. It seems to have good efficacy in helping either control or improve clinical signs. And so because it's fairly minimally invasive and because the complication rate has been so low, it would not be unreasonable to consider, I think, in that situation.
Dr. Venable: So if I have an owner that wants to do this, what do I prep them for? Like what are the steps to get? Because I know you said they have an angiogram. So what is the process for all of this?
Dr. Culp: Yeah, we usually just it's fairly minimal. We usually offer them whatever staging it. A lot of them come in staged at that point with blood work and chest rads and ultrasound. I usually will recheck an ultrasound immediately before the procedure, just to make sure they don't have you reader obstructions. If they have your reader obstructions, which is only happens maybe five to seven times of cases that have been coming in for embolization, it's uncommon. But if they do, then we would offer them stenting prior. And usually, in those cases we would do a percutaneous urethral stenting for that and then embolization if they wanted to do both, if they wanted to just do the ureters, then we would all for the years, if they were subclinical or minimally clinical for the prostate itself, and then we CT them beforehand to evaluate the blood supply. We're learning a lot about that. To know it's most of them is fairly similar, but it does get altered by the tumor. Some dogs have branches that are abnormal. So kind of finding their branches to the prostate can be a little bit challenging. So it's nice to have a CT beforehand and rarely will, you know, pick up other things going on right there too. Almost all of them have some level of lymph node lymphadenopathy, whether it's from the tumor or whether it's from inflammation. They never really know. But it's not unusual to find bigger lymph nodes back there. So we always kind of do those workups. And then that's pretty much it. And then if they're otherwise able to undergo it, then we'll offer them the embolization.
Dr. Venable: And then is that a one-time procedure? How does the embolization work?
Dr. Culp: Yeah it's a great question. So for the prostates it's typically one we try to take them down to stasis. So we try to take away all their blood flow to the prostate on both sides. All but two dogs I think I've seen have had bilateral blood supply. There have been two dogs oddly, you know, and they have one single prostate arteries. So we'll only treat one side in that case. But most of them have bilateral. So we'll treat them and try to take it down to no flow for other embolization like particularly in the liver that we might offer multiple embolization in those cases because they're more likely to be vascularized or again, to kind of steal blood supply from other liver lobes. But the prostate usually doesn't seem like it does that.
Dr. Venable: And then do you do a specific follow-up to monitor how that's working? How does that part work?
Dr. Culp: Yeah, we ideally will recommend that two weeks after they start chemo or continue chemo if they're up for it. And so then they'll get their kind of continued chemo evaluations as they typically would and get their ultrasounds with that. If they're not going to do that, then we try to recommend that they get an ultrasound usually a month after and then every three months after that, if they're up for it or if there's anything that changes clinically.
Dr. Venable: Okay. But it doesn't sound like really anything specific as far as the IO goes, that you have no imaging or follow up. Really?
Dr. Culp: No, not yet. I don't think so. There's, you know, when we when I was first doing them, I was ultrasound in them like death daily. So they had no idea what to expect. And you know, was everything in a rupture and what's going to happen and all this stuff. So I was pretty nervous in the beginning. So I will oftentimes ultrasound them the day after just to make sure there's nothing major going on. But honestly, it hasn't been something where we've been picking up too much with that.
Dr. Venable: And you mentioned chemotherapy with prostate. Is there one that you've seen that or that you usually recommend? Because I feel like we don't really know. So I'm just curious if you've seen anything in your research or just experience.
Dr. Culp: No, it's a great question. You know, I will say what I've used historically is either been might as an intruder have been blasting historically for livers. I've done carbo and dogs. So it kind of done a mixture of things in different locations. But no, I oftentimes will consult with you all and see what you think is the best thing in a particular case.
Dr. Venable: And you mentioned the liver. Where else are you recommending embolization or where are you doing it?
Dr. Culp: Yeah, most of what we do is prostate liver, and nasal. For the majority, I'd say that's 95% of the tumors. And I kind of think about it like, what are those tumors where the options are either we don't have a surgical option or the other options are not as good yet as what we would like. So for the livers, you know, I see a lot of liver tumors come in. And oftentimes they're just like the big ones. And then you see them, and you're like, oh, there's a good surgical option here. So the majority of the livers that I see with where the owners think they're coming in for embolization oftentimes become surgical cases, which is great. I think that all in all, if you can remove this massive tumor that's in there versus kind of stabilize it, I think that's better. So we'll usually do that. But then there's those cases where it's in a really horrible location or it's a large section of liver. And so those cases we might offer embolization for, for the nasal tumors, we always recommend that they talk to on first and kind of get the whole conversation with them and see what options are available with them.
Dr. Culp: And then if they are not going to pursue that or they want to consider something else, then we'll talk to them about embolization as well. Anecdotally, I think that the circle mowers respond really well in the nasal cavity. I don't know if this is why, but, you know, sarcomas tend to have like obviously like a little bit more of a controlled environment or more distinct borders or a more obvious blood supply. And they really have a good blood supply. So maybe that's why. But I honestly have no idea. But it's something that we do see from time to time. And then, you know, we'll see. Random tumors. I've done maybe 5 or 6 kidney tumors at this point. So that's probably the fourth most common one we see. And then, you know, you'll see the different sarcomas and challenging locations and other things. But most of those are kind of just as they come along. And there's not other great options for them.
Dr. Venable: With the nose. Do you guys still get oral nasal fistulas or any of those kind of side effects we can see with radiation? Do you still see things like that?
Dr. Culp: It's possible. It's the blessing and the curse of a good response. If you have a tumor that's invading hard palate, maxilla, whatever it is, I've had 1 or 2 cases that are in the palate that have had developed to witness a fistula afterward, because the tumor really dies. I don't stress much about the ones that are kind of on the top, the maxillary ones, they usually tolerate that. Of all the cases we've done, we've only had one case of partial skin necrosis. So I mention that because even if the maxilla, you know, the tumor goes away from the max, they end up with a hole. As long as they have good skin coverage, it's probably fine there. But in the oral cavity, we just have to be a little bit careful when it goes through the palate.
Dr. Venable: What about nasal plane? You know, dogs can get those nasal plane them. Swaim and a lot of owners aren't a big fan of the surgery because it's so cosmetically different with embolization help at all with that? I mean, is that an option?
Dr. Culp: You think that's a great question? I think I haven't done it. I my worry there would be you probably are going to end up with a big wound because if it actually works, you know, and those ones, especially those ones that are kind of the full rostral aspect of the nasal plane, if you actually got it to work, it's just going to be necrosis kind of coming back. So I probably that would be one I would be a little bit more reluctant to do. I've had a couple of cases where they've had tumors like in the lip region and not truly like partially on the bone and then coming up into the lip that I've treated, but on the nose or nasal plane them itself. I think that would be a tough one.
Dr. Venable: So if I'm thinking about options for patients as far as I-O goes, should it? Is it something where if you can do surgery, that's still the best? And if you can't do surgery, maybe this is an alternative to radiation, depending on the location, like the liver, we don't. Yeah, I irradiate the liver. So that makes sense to me. Same with the kidney. And so is that kind of the way to think about it. Is that how you think about it?
Dr. Culp: I think so I think that's a really good general way to think about it. You know, I think in in human medicine, there's a few tumors that they actually feel like interventional is better for, like the classic example. And this is not a super common tumor, but there's an angio mild lipoma. It's I came in with loud, mild lipoma. A lot of I remember that humans get in their kidneys, and they've shown that embolization is the best treatment for this. Like, much better than a nephrectomy is a partial nephrectomy actually takes out the tumor and usually is curative in those cases. So I think there's a chance that that may develop over time for our cases. I think that where we are now, I think that the one argument could be that maybe, and again, I'm a little biased, but maybe the embolization is a better option for prostate tumors and maybe some of our other options.
You know, I've done prostatectomy before as well. And I think that that's something that's always on the table. But if your goal is truly to control clinical signs and make the local disease not an issue, I think embolization has a chance for that. So I think maybe that's something to consider. But for livers, for me personally, I think if you can get the liver to Moran, I just feel like it's such a space-occupying lesion. And if especially if their signs are that they're not wanting to eat or you have the chance of it rupturing, I feel like maybe getting it out is probably the better scenario. So I always try to push for surgery in liver cases if it's on the table. Yeah. You know, things that we haven't done as much. But I wonder about things like bone tumors and things like that.
You know, that some of the original research out of CSU, actually, Steve Withrow was doing stuff like in the 90s, not surprisingly. So they are kind of at the forefront of everything. But he was looking at, you know, local chemotherapy for bone tumors and, and that kind of thing. So I think we have to consider all of those options. You know, if we found something that was better than amputation, that would be great to take, right? So I think all of that has to kind of be on the table. But I think we're still a little early to know for most of these if some I-O procedure is going to be better than a surgical option.
Dr. Venable: Yeah, this is really interesting. And talk to you about the blood supply. It just makes me wonder, is a major sarcoma a good option for I-O? I mean, I realize that the spleens ruptured. No, but yeah, like maybe a sub two or something where you could do this procedure. Have you been able to do it on any humans you sarcomas?
Dr. Culp: That's a great question. So there you know, I recently had a case it didn't go, but it was a case of a splendid tumor. And so reason I mention that is that it made me do some research into whether this is being done. And what's interesting is there's 1 or 2 case reports, if that looking at any kind of splenic tumor embolization in humans. And so all that to say, it's probably something that's unusual or something there's probably not going to be a ton of indications for it. That being said, there is maybe a consideration for whether we should consider embolization for liver Mets in a major sarcoma if it's truly that the issue is that they're bleeding from the Mets, you know, and we see those occasional cases where they bleed a little bit, get better, bleed a little bit, and they kind of come back and forth and, and they don't bleed so bad that they, you know, they need to be euthanized at that point.
Maybe those are options to consider. That's obviously for the owner. That's incredibly motivated. And if we can do it minimally invasive to the point where it doesn't really impact the quality of life dramatically in the short term, then something that can be considered for the subcu ones. I've treated a few not technically commands, but from the Oklahoma standpoint, I've treated a few vaccine-associated sarcomas in cats, which I think may be an option. The challenge there, again is that when you treat those, and they're so expansive on the skin, I worry that you're going to get skin necrosis on some of those. And so thankfully the skin has a lot of redundant blood supplies. So you can probably get away with it. But I think maybe there might be an indication in some of those cases to consider it for the sarcomas.
Dr. Venable: And what are some of the typical complications from IO? Is it basically wound formation?
Dr. Culp: It's possible. Yeah. I kind of think about the liver separately from the others, because the liver complications tend to be a little bit more. So knock on wood, the prostate ones have been super highly tolerated. The biggest things I was warned owners like a non-target embolization could be catastrophic if we emphasize the bladder, you know, the urethra coming down along the penis, potentially all of that.
We could see massive necrosis there and could have major complications from that. Thankfully, we haven't seen that. The one thing that's reported in both men that undergo prostate embolization, and I've seen it in a couple of cases in dogs, is that they could get urine retention over the early few weeks after embolization, probably from local inflammation from the procedure. And so in those cases, I think I've had three in those cases. And we've just put in a red rubber catheter for two weeks and then pulled it. And then during that time inflammation goes down, prostate probably shrinks. And then you're able to pull in. They've all been able to urinate afterward. So it's a pretty soon after the procedure complication that we've seen in those prostate embolization cases. I don't think that we appreciate the true embolization syndrome in the prostates. And I'll talk about that for livers. So I haven't seen most of these dogs go home the next morning, and they're feeling unaffected pretty much by it because it's a small approach. Doesn't seem like it's that painful. And so it's something that's really tolerated. Nasals.
Similarly, I do think there's a little bit of discomfort sometimes in the nasal cases in that I've had a few, dogs kind of fall at their nose after the treatment. The biggest thing, honestly, with the nasal tumor cases and the thing that I've learned to warn owners about is that they start to sneeze up the tumor. And so I kind of have to prep owners that like chunks of tumor are going to come down. And so that's one of the big things that I kind of prep them for is that once as it dies, they actually like kind of, sneeze it out. Livers are a little bit more unique, and those are ones that sometimes go home the next day and then sometimes need to stay in the hospital 3 or 4 or five days just depending on their response. They get something called embolization syndrome, and it's well described in humans, but it's this group of signs or biochemical changes where you can tell that something massive is going on in there. And so basically, for, our patients, what I think we see is we usually see a generalized peritonitis. We can see abdominal pain and occasionally abdominal fusion. They get a change in their white blood cell count.
And then they get obvious changes in their liver enzymes. And so I'd say in my experience it happens about 50% of the time. So I always warn others about it. I don't keep them in the hospital for the whole time because it can last 7 to 14 days, but they can be pretty lethargic during that time. So I prep owners for that, that this is something that they're going to have to, you know, have a little bit of nursing care at home from the standpoint of kind of making them comfortable and making sure that they're still eating and drinking and able to go outside. But they can be pretty quiet for the first seven days, and usually, at seven days, they'll start to get feeling better. And so I think it's just a matter of both the changes in the liver and the liver enzyme increases, and then the generalized kind of peritonitis that they get from that. But they can have a pretty big response. I mean, their liver enzymes will go up. And we did a trial looking at them a day or two after and then 30 days after. And they in that first couple days after, they'll go up thousands of percent higher. They're really like the highest liver enzymes that we see. And then by 30 days after they're totally they're either back to where they were pre-treatment or improve. So it's it's amazing how quickly it happens and then how much it improves pretty quickly to do.
Dr. Venable: You notice the ones that get that syndrome. Do they have a better response overall.
Dr. Culp: I always wonder that you know it's in humans. They haven't really set parameters for how they define embolization syndrome. The studies suggest that if you get embolization syndrome, your long-term outcome is actually worse. Your prognosis is worse, which is interesting. The theories are all over the place about why it happens. Is it because you get massive necrosis and it's like your immune system responds to dealing with these liver cells that are dying? Or is it because there's small amounts of pancreatitis, either from inflammation in the liver or because there's like small amounts of non-target embolization? You know, the pancreas is blood supply comes off right before the liver's blood supply. And so there's always a chance that you could emboli as part of the pancreas as well. So is that why it's happening? Does it happen in the cases that you give chemo because they're also getting chemo? We don't know. I don't personally know yet. I think that we see really good responses in both situations and then sometimes lesser responses. And sometimes I see these ones where in this massive tumor and it's super vascular. And I'm hopeful that the response is going to be really good because we're able to take out a lot of it. But then I'm also worried that maybe because they get this big necrosis, they're going to be sicker. And then sometimes those dogs leave the next day and never show any signs. So I've had a really hard time predicting.
Dr. Venable: And yeah that is interesting because you would think like you said, if it's a giant tumor, all this, you know, to me it almost reminds me like d granulated mast cell tumors, right? Like I could the bigger the mass would be do radiation or something. I'm always much more scared. But it's really interesting that it's so unpredictable and its survival might be worse. So that's that's also unfortunate.
Dr. Culp: Yeah. No. Totally.
Dr. Venable: So before I oh, you know obviously you at UC Davis can do it. But for those pet owners that live in other parts of the country, who else is doing this?
Dr. Culp: Yeah, it's expanding really nicely, which is great. So from the standpoint of stenting, I'd say it's very available in a lot of the specialty clinics. Now, you know, when we think of the kind of like, again, the, the mainstays or the kind of the bulk of the stenting we look at, like on the benign side, tracheal stenting and then on the malignant side, urethral stenting. And so there is a ton of clinics that can offer that pretty much every university. And then I would say most if not all of the major private practices out there as well, probably can do those types of procedures, which is great. And I think the ones that are less common are maybe like the percutaneous urethral stenting because it involves getting access into the kidney, you know, in a noninvasive or minimally invasive fashion. And then the vascular therapies are definitely available less commonly, although that is expanding a lot as well. And so I think we're starting to see that grow and grow and grow. There's, you know, great clinics all over that are, are starting to do these types of procedures. So thankfully, I think it's something that in the next 5 to 10 years, people probably won't have to travel very far, all to get any of these therapies.
Dr. Venable: So is there somewhere like is there a a group or somewhere you could look online to see if there is someone near you that does like the prostate, like the embolization? Is there somewhere to look that up?
Dr. Culp: Yeah, I think a couple of options. So there is a society now that's related to specifically to interventional radiology. It's called VIRIES the Veterinary Interventional Radiology & Interventional Endoscopy Society. I think their website is very small. So that has a lot of the events and things like that on there. I don't think that it lists actually direct options for that. And so what I would say is probably the best way is word of mouth and talking to local specialists in your area to see who might be available. And then from there, kind of searching their sites just to see if that's actually something that they offer. I've noticed a lot of people on their websites now are marketing that they have these different techniques available.
Dr. Venable: As far as stenting goes, because I want to talk more about this as well. In my experience where I live, actually, the internists do it more than I've seen the surgeons. Is that a common trend, or would you say more surgeons do stenting and IO in general?
Dr. Culp: No, I think it's for everyone, which is amazing. And that's what's cool about various, you know, the society is that when you go to those meetings and again, anybody that's on here that's interested in this stuff, you should definitely check out these meetings. They're really fun and really collaborative. It's a small group of people and it's a lot of just conversations and discussions. So if there's interest in these topics, you should definitely check them out or it's going to be in Japan next year. So that's exciting. And from that standpoint, yes, I think it's nice because it's open to everyone and anyone that has an interest. You know, it's interesting. I'm sure you know this, but in humans, it's like almost all radiologists. So it starts as a radiology residenc,y and then they do a fellowship in IR, and then they kind of branch off into their different areas. It's only been, I think, in the last 5 to 10 years that they have actual AI or residency into fellowship training. It's mostly been the the true diagnostic radiologists that then go on to do AI are from there. And so we're very different from that standpoint is that, you know, yes, a lot of the people that are doing this are internists and surgeons. But if you look kind of across the board, there's emergency critical care, there are radiologists, there's people in lots of different specialties doing this. So I think it's very open for that. And I think you're right. I think probably in practice, I wonder, I bet there's more internists that are actually doing the stenting procedures than there are any other specialty.
Dr. Venable: That's my experience when it comes to stents. And, I am curious, what are your thoughts on, you know, bladder tumors? Because that's where I see stenting the most. I've always heard, you know, stent right before they abstract which, you know, we never quite know do you have more specific parameters, or do you guys just stent everyone that has a bladder tumor?
Dr. Culp: No. Good question. Yeah. Similarly, I talk people out of it when it's not at that stage at. So maybe a stage before they fully obstruct. So I kind of talked to people owners or even referring veterinarians about, you know, when they going outside and they try to urinate 2 or 3 times, and then they get a stream out, but it's still a struggling stream. I will still I'll offer it. In that case, I kind of think, like, what's the point where this is going to actually improve their day-to-day quality of life, that even if there's a complication, it made it worth it to try. And so, you know, the easy ones, as you said, are the fully obstructed. You know, it's nice that there's an option there. They're fully obstructed. Even if you can't get a stent in day one, you cat them in, have a few cats or however long you need, then put a stent in and you can oftentimes fix that. And then up from that would be those cases that are go out, try a few times, can't urinate, and then maybe start to get a stream out.
So maybe they're okay. They're not in a life-threatening situation, but they're super uncomfortable. That's kind of where I am for the majority of our urethral stenting cases. For the ureter, you can maybe be a little bit more specific for the ureter once they have hydrant differences or extension of the pelvis enough where you think that you can get access percutaneous, we will often offer it then. So I would act sooner on a year, or maybe because once the ureter becomes fully obstructed, it can be really hard to get your access through the tumor. So it's nicer to get to it when it's maybe earlier than being fully obstructed. But it is showing signs of hydrogen of roses.
Dr. Venable: Okay, now that makes sense. And is there ever a scenario for you where you wouldn't do a stent for a urinary bladder? Because I've kind of experienced different things. Do you have a scenario where you would say outside of you don't think the dog needs it, but, you know, let's say the dog could use it, but is there some parameters like tumor size or location?
Dr. Culp: Yeah, it's a great question. I think we have a more specific conversation about incontinence for owners that have tumors going through the entire length of the urethra. And so there's a coupl of scenarios for that. You'll get a smaller dog that has a tumor where it's going almost the full length of the urethra. And basically, at the time you stent them, you're going to stent 80 or 90% of the urethra, and then there's a bigger dogs where you might need to place multiple stents. And so the multiple stents become partially a financial decision because it's not cheap. And then the stenting, the whole urethra or even stenting out into the vestibule, like having it go through the papilla. We have like a real heart-to-heart with them this is why they're very likely going to be in con them. And so it's interesting, you know, it's uncommon.
Honestly. Incontinence is the big complication probably for urethral stents. And you know, you talk you look at the studies, and it's either 2,530% it's variable. The true like incontinence where they're leaking all the time after stent is actually really uncommon. Like where they're just constantly leaking. And you look at their bladder and their bladder is tiny because the urine basically comes right out. That's uncommon. What's more common is kind of the typical what we'd expect in the, you know, an older dog, incontinence, where they're just at home, and they're sleeping, and they have like some urine that collects there. That's I think, in my experience, what we see more commonly. So most owners can handle that level of incontinence. But when you're stenting the whole urethra, you're pretty much signing up for that.
This is a scenario that you could run into. The other thing that I get worried about is when we stent into the vestibule. We've had one dog that it definitely impacted quality of life. I think that they were super uncomfortable having it there and would kind of irritate the area a lot afterward. And so I always worry about that. I remember the dog, the dog's name. I remember all of that really well because it was, a scenario where they were I, you know, I felt bad about everything that kind of happened with that. And they were uncomfortable afterwards. So I do think that's something where we have more of a conversation with those owners that maybe this is something not to consider here. Or are you kind of up for that? This is something to try and if it doesn't work, then we might not have other good options.
Dr. Venable: And just say no, that it's good to good to know. And I think I've also seen that where once in a while I see dogs that have to be in diapers because they're just dribbling. But a lot of them, it is kind of like that old where they're sleeping, or maybe just here and there, they'll dribble around the house, which, you know, which also can be hard because most of these dogs are on chemotherapy. If that's not also ideal and just sort of complicates things, but really interesting. I love hearing your experiences because you've done, you know, seen this way more than I have at least. And, you know, what are some of the things on the horizon that you think are interesting that are coming down the aisle route?
Dr. Culp: Yeah, I think, a couple of things. I think that there's more routes that we can go with vascular therapies. I think that we can start to consider more local delivery of other drugs or different drugs, new things, and new targeted therapies that come out. One of the things that we're starting to look at very, very early stages, but looking at ultrasound-guided delivery of agents to tumors, I think that's something that growing in human medicine. And thankfully we're able to with where I'm located in Northern California. There's some great human medical facilities here as well that we're working with to look at local delivery, ultrasound-guided therapies that you can actually deliver drugs to tumors. So technically still in the realm of interventional radiology, and interventional oncology procedures. So I'm hoping that there are some things coming down the road for that.
I think that we started to evaluate ablation more as well. So for anybody that doesn't know ablation is it's either chemical ablation or thermal ablation. You kind of you're essentially delivering something to a tumor that causes cellular death. And so we don't use a ton of chemical ablation, but we do thermal ablation with microwave, cryoablation. So those are things that are really nice as well. So we started to use that on tumors, metastatic lesions and things like that. I think that one of the areas that's growing for that is potential for the use in bone tumors as well, is essentially treating the tumor locally and trying to avoid an amputation in those cases, essentially deliver either microwave radiofrequency ablation, something to the tumor itself to kill the tumor but leave the leg in position. So I think that those are things that are starting to come along. And I do think those will be potentially some more commonly offered over the next 5 to 10 years.
Dr. Venable: And what about AI? That seems like, you know, it's such a big deal everywhere anymore. Are you seeing that anywhere in surgical oncology? Is AI coming up at all?
Dr. Culp: I'm sure it is. You know, we have some great people that are interested in AI here. And so they're doing some interesting stuff, mostly from the internal medicine standpoint and looking at diagnostics that they're using for different diseases as well, and categorizing patients, which I think is really interesting, I haven't seen that much related to, and I'm sure it's coming, and I'm sure it's out there, and it'll be a good one to see. I feel like I need to I have two younger children, and so I feel like I need to start figuring this stuff out a little bit because it's going to be their future. So I need to know what's going to be happening pretty soon.
Dr. Venable: I yes, I have two little kids too, and I'm already shocked by how much they can do on phones and tablets. And I even try to minimize screen time. And I'm still I know they're going to just be doing circles around me pretty soon.
Dr. Culp: I feel that I feel that.
Dr. Venable: Is and, you know, also for anybody who is interested like in, you know, the IO or some of the things that you guys do up there, what's the best way to refer cases for you? Is there an email? How do people go about that?
Dr. Culp: Yeah. You know, if for people are listening to this, they're always welcome to email me directly. I'm happy to talk about cases. And I think especially if you're interested in the ear stuff, you know, that's cases that I would be seeing. So happy to chat with you about that and see if it's a case that there might be an option that we have or what options we have. So my email is pretty straightforward. It's just w call my name, CULP at UC davis.edu. So you're welcome to reach out and let me know if there's any questions.
Dr. Venable: Well that is very kind of you to give out your your work email. So thank you so much because yeah I know like you said, as a med OG there are times where I'm like, would this be a write a good case? So thank you so much for sharing that. And as we're wrapping up today, I think this has been a really great conversation, especially. I learned a lot because this is an area we're outside of, like the urethra stents, I don't really know a whole lot. So something I always like to ask on this podcast is who is someone else that you would recommend you think would be a good guest on the show?
Dr. Culp: Oh man, that's a great well, should I think outside of my areas of specialty or within I mean, there's a lot of really, really great people, I think. So I'll plug a few of my of my buddies that either have trained or been involved in that. So there are some really great people at the University of Pennsylvania, both Dana Clarke, who's been there for a long time, she's a critical list, and she's done a lot of things related to interventional radiology. And then a newer colleague who I worked with for a long time, Erin Gibson, who was a resident of mine and then stayed to do a fellowship with us. She's also out there doing a lot of interventional things as well. There's amazing guy in Southern California, in the San Diego area. His name is Chris Thomson. He's doing a lot of really cool interventional-related stuff as well. And then Maureen Griffin, who was another resident of mine, is heading out to CSU's going back to CSU to do surgical oncology. So she's a great resource for a lot of the newer surgical oncology techniques as well. And there's a million other great ones out there. So just mentioning some of the people that I've worked with most recently. But yeah, there's a lot of really, really great people out there.
Dr. Venable: Well, awesome. Thank you so much. We'll definitely reach out to them because this is a really interesting developing field. I love all this stuff, all the different options that we can offer now. It's wild compared to what I remember what we started with. And now it's like, man, there's there's a lot of different things we can do.
Dr. Culp: And it's really cool. It's exciting. It's, it makes it really fun to to come in every day and to think about the things we can offer. And then it's, you know, it's nice to when you have little areas that you can kind of focus in. It's nice to be able to meet with those owners because they're seeking out that option, and they're seeking out the opportunity for something that's a little bit different. And so you oftentimes make really nice connections with those owners. So that's always a really exciting part of this as well.
Dr. Venable: Yeah that is amazing. Well again thank you so much. I really appreciate you being on our podcast now.
Dr. Culp: Thanks for having me. I appreciate your time. Thanks for the invite. Yeah, I look forward to hearing more about what you're doing.
Dr. Venable: Well, that's it for this episode of the Veterinary Cancer Pioneers podcast. If you enjoyed this episode and gained valuable insight, we would be so grateful if you could share our podcast with your friends and colleagues. And it would be even more wonderful if you want to give us a five-star rating, positive review, or any kind of feedback on Apple Podcasts or wherever you listen. The Veterinary Cancer Pioneers Podcast is presented to you by ImpriMed.