The Evolving Role of Lymphangiography in Interventional Radiology

[Dr. Chris Beck]
What does your lymphangiography practice look like? Which kind of patients are you taking care of? I get a lot of questions about it, but I'll just open it up. What does the practice look like for you right now?

[Dr. Bill Majdalany]
Absolutely. Everywhere I've been along my path, the lymphangiography practice has been there. I think that's really one of the salient points. I've never had to try hard to build a lymphangiography practice. It's there, and the patients need the help. Really the biggest thing is the visibility of, is there somebody there with the know-how, the willingness to take it on? I can't think of a single medical center, community hospital, academic hospital, private practice, et cetera. If you're servicing a hospital that even has 100 patients, 100 beds, for instance, you can't tell me that they don't do a lymphadenectomy or any type of prostate surgery, spine surgery, et cetera.

All of these things are where you can run into lymphatic things. How do they get managed? Can they be managed by you, or do they need to be sent elsewhere? The reality is almost all of these things can be managed by an interventionalist who is interested in doing it. I think anytime we can solve a problem for a colleague in our hospital, that's a natural way to build a practice.

[Dr. Chris Beck]
Sure. How did you yourself get interested in it, specifically? A lot of IRs-- At least one of the reasons we wanted to cover this topic is we feel like this can be a blind spot, not only in training, but just sometimes it's, your interventional radiologists sometimes are asked to do a lot of things, and sometimes it's an easy one to say, "Just not going to make this part of the practice," right?

[Dr. Bill Majdalany]
Sure. I think a great deal of it goes back to my own training. I did my residency at Brigham and Women's, which is one of the few places that was still doing pedal lymphangiography, along with the University of Pennsylvania was one of the places where thoracic duct embolization was done back in the early 2000s. It was largely because we had a population of patients with mesothelioma, and we were international center for mesothelioma patients who would come in. They'd have these large extrapleural pneumonectomies, et cetera, invariably that have great outcomes from a mesothelioma standpoint, or at least as good as you can imagine, but they would have complications with lymphatic injuries.

You want to get those patients back on chemotherapy, you want to maintain their nutrition, you need to do all this stuff, and a chylous leak or a thoracic duct injury isn't going to allow that to happen. You can imagine that the desire to go in and re-operate on somebody where you've just maybe put intrapleural, intracavitary chemotherapy, et cetera, is non-existent. I remember actually, it was my first rotation in IR. I was a first-year resident, and IR fellows all were shying away from this case because they knew back in the old pedal lymphangiography days, it's going to be four or five hours per case.

[Dr. Chris Beck]
Sure. It's a while.

[Dr. Bill Majdalany]
They all jumped into other cases, and like, "Oh, hey, this is a great first case for you to do."

[Dr. Chris Beck]
Yes. First-year resident. What else? Pedal lymphangiography.

[Dr. Bill Majdalany]
I go in. Of course, the attending does almost all of it. I'm doing my best to not screw things up. We end up doing this case. It was so transformative to have seen the patient before, who's A, not eating, B, has chest tubes in, is losing all this vital fluid, and a day later is functionally cured. Then seeing it again and again, whether it's for esophageal surgeries, or CABGs, or post spinal surgeries, et cetera, we did quite a few at Brigham and Women's. Along that time span, 2011 at Children's Boston, I also rotated there, they had moved from doing pedal lymphangiography because you really can't do it in these really tiny kids.

They had gone along with nodal lymphangiography, which is a blast from the past in the 1950s and '60s. They used that as a way to easily access the lymphatics and do your lymphangiography. We started doing it in adults, and it made things even so easy by the time I was a senior resident and a fellow. We were doing these very often in several-week mini-cases-

[Dr. Chris Beck]
Wow.

[Dr. Bill Majdalany]
-before things really caught on and started spreading. In a way, I got to see this lymphatic revolution where it went from a really challenging procedure that was only done at a couple of places to something that could be easily within the armamentarium of any IR, anywhere, and to great effect. What's really continued to change is we've moved beyond just thoracic duct embolization, into so many other types of lymphatic interventions. I think that's really where the excitement is, that you can start with just lymphangiography, but where you branch off and where it goes is tremendous.

[Dr. Chris Beck]
Out of curiosity, I've never seen or performed pedal lymphangiography. How long actually does it take?

[Dr. Bill Majdalany]
Hours.

[Dr. Chris Beck]
Okay.

[Dr. Bill Majdalany]
There's a skill to it for sure. Not just even injecting the dye between the toes to try to do it as painlessly as possible for patients. Then you're milking that blue dye into the dorsum of the foot and then cutting down on these little skinny vessels, and cannulating with a 30 or 32-gauge needle. It's something that is somewhat lost on us because, to a certain degree, we do these bigger actions with much bigger needles thoughtlessly. Historically, in the earlier days of lymphangiography, '60s, '70s, '80s, et cetera, a lot of the techs that we work with became so proficient that they would do a lot of the pedal lymphangiograms themselves.

I know even here, I remember them telling me that, "Oh, yes. Some of our senior techs used to do these and these, and they did them fairly quickly." I was like, "Wow," because that skill was lost right between the '80s, '90s, and 2000s. It went from lymphangiography being there as a diagnostic modality to stage cancer to differentiate infection from inflammation and malignancy, et cetera, to CTs and MRs around. Who wants to do a lymphangiogram, that isn't as sensitive or as good, never mind the time and the potential complications with an incision, et cetera? It passed away with time and now it's really been revived. Not from a pedal standpoint, but from a standpoint of, re-exploring how the lymphatics interact with the pathophysiology we may be treating.

[Dr. Chris Beck]
Say a Backtable listener is now feeling very inspired by this episode and they want more-- We actually do have some good episodes on this, and we'll link to them in the show notes. Other than having to learn this over multiple years with multiple sources, do you have any good resources that you can point people, either like, "Hey, this is just where you start, this is the ABCs of lymphangiography," or, "This is a good understanding of the lymph system," whether it's papers, lectures that you've listened to, or even given?

[Dr. Bill Majdalany]
Absolutely. At the risk of sounding like I'm plugging myself,-

[Dr. Chris Beck]
No, plug away, dude.

[Dr. Bill Majdalany]
-there was an issue of seminars of interventional radiology maybe in 2020 or 2021. I was a guest editor, but the whole issue was dedicated to lymphatic imaging and intervention. It's 12 different articles written by 9 different authors. You have a good lay of the land from all around. It's broken down to lymphatic anatomy and physiology, and then based on traumatic chylothorax, how to approach that with algorithms, non-traumatic chylothorax, chylous ascites, and lymphoceles, hepatic lymphangiography, et cetera. It really covers a lot. Prior to that, one of the gurus, Max Itkin, had a similar thing in techniques. That was a few years before maybe 2016, 2017, but those two things really have a lot of the information, including the setups of how to do it, et cetera.

[Dr. Chris Beck]
We'll actually link to both of those references, seminars and techniques whenever they cover an entire topic on something. That can actually be just pure gold. Those are fantastic. You were the editor for it. Who were some of the other contributing authors?

[Dr. Bill Majdalany]
Max Itkin and Greg Nadolski, the group out of Memorial Sloan Kettering with Ernesto Santos, Wally, Waleska Pabon-Ramos from Duke. I actually had invited-- One of the articles was from plastic surgery on the management of lymphoedema. I think it's really important to hear the perspective of our plastics colleagues. What could they do for us? What can they do for these patients? Because almost always, we'll see somebody with leg swelling, and we're like, "I don't know what to do for this patient." Debbie Rabinowitz discussing pediatrics, Matt Hawkins in Indigo discussing lymphatic malformations, et cetera, et cetera. A good cross-section across the country, domestic and international. Claus Pieper from Germany, talking about different techniques for MR lymphangiography as well. He's a guru in that.

[Dr. Chris Beck]
Very cool. Is there anything that I didn't ask about-- Actually, how about this? If you just had to sum it up and say, you've been at four different institutions, what has been the top three takeaways or success points for you as far as being able to build this practice at each place that you go to?

[Dr. Bill Majdalany]
I think number one is just giving it a try. Like I said, almost any IR practice at some point has to do a para, a thora, a chest tube, something more than other clinical services are able to do, or maybe needs imaging, depending on your local practice pattern. Understanding how to work it up, and then coming back and adding value to that, to the care of the patient, I think gets you a lot of respect from the other people who are taking care of patients. It's easy to shy away and be like, "Okay, hey, I stuck the needle in, and I'm walking out. Hey, you guys just pull it when the patient is done and send them up."

You sit there and you see the fluid, and you say, "Oh, hey, take that next step, and say, I'm going to send it for fluid testing based on what I see." If it's a chylous, I want to send it for triglycerides. What if it's non-chylous? One of the things that I've really learned and really talked to people a lot about is how do you work up lymphoceles? There's always this misconception that people want to send it for triglycerides, but that's actually not what you should be sending it for. What you should be sending it for is a cell count because the triglycerides don't filter into the lymphatic system at the level of the groin.

They filter in from the mesentery and that comes in at the cisterna chyli. It's a much higher area. I've seen this in partners at different institutions. They say, "Oh, I sent it for triglycerides. There's no triglycerides, it's not a lymphatic leak." Actually, triglycerides tell you that it's a chylous leak. They tell you that it's a lymphatic leak. What you really want to send it for is a cell count, and what you see is a preponderance of lymphoceles. Typically, greater than 70%, 80&, 90% of the cell count will be lymphoceles. That's what I always tell people is that, it has that appearance. It looks like urine.

The triglycerides will be low. You'd send it for a urine creatinine to work it up. The creatinine is low, but the lymphocyte count is out of the roof. That's how you then know that it's going to be a lymphocele. You do a lymphangiogram. Now you've done a tremendous service for the patient. You've fixed their problem with a 25-gauge needle, that otherwise would be marsupialization or something else. I think there's always this misconception of it's a lymphatic leak. We're going to do dietary modification. The dietary modification doesn't fix a groin leak. The small bowel doesn't circulate in that way.

[Dr. Chris Beck]
It's the back pressure.

[Dr. Bill Majdalany]
Yes, exactly. What I always tell people is that there is an understanding of lymphatic anatomy physiology. It's a very distinct circulatory system. It's very different from how arteries and veins work because it has three different and separate components, which don't communicate until they get to the cisterna chyli. Each component is unique. The mesenteric component is going to be lipid-rich. The hepatic component is going to be protein-rich. The peripheral component is going to be electrolyte and lymphocyte-rich. Knowing how to test for a leak in each component is the most important thing.

[Dr. Chris Beck]
That's a good tip. Why is it that IRs shy away from this? Do you think it's under-recognition? Under appreciation? We're scared of it? Under training? Under education? Combination of all these factors?

[Dr. Bill Majdalany]
The typical medical student gets very little teaching about lymphatics. Hours, or oh, you hear about lymph nodes and metastasis. In and of itself, the actual understanding of the lymphatic anatomy and physiology is not something I was ever taught in medical school. Certainly, even through radiology residency, had I not gone through the residency that I'd gone through, I would not have been exposed to it. I can say that a large majority of people, as recently as 10 years ago, did not have education in this. At least even in the IR spectrum.

Now it's routinely at many meetings. We discuss lymphatics and things like that. I think that's part of it. I think the other part of it is that there are so many things to do. There is this perspective, misconception potentially, of, oh, I don't want to have to get all of this inventory, or, oh, it takes a long time, or et cetera, et cetera, et cetera. It's just one more thing to learn. To me, it takes a routine procedure and you problem-solve and add a big benefit. Most importantly, I look at it from a building practice standpoint. It was not lost on me as a resident.

We worked with a thoracic surgeon so closely. A lot of academic places were not doing arterial stenting or even the IVC filters. Oh, who does the IVC filter at your hospital? This, that, the other. It's funny, when you think about it. It was not lost on me that the thoracic surgeons relied on us for everything when it came to their patients. Whether it was, if they had a DVT, we would do the thrombectomy, the IVC filter, the enteral intervention. The arterial intervention, if they were doing a gastric pull-up and they needed a celiac stent. The thoracic duct embolization surgeon said it was a way that practice and relationships were built.

When you can solve a problem for somebody else, they're going to go to you because they trust you, when you can solve their hard problems, to solve their simpler problems that a lot of other people could trust. Particularly when you have that face-to-face interaction, they know that you care about their patients. They know that you help them achieve excellent outcomes. To me, that is a cornerstone of lymphangiography and lymphatic interventions is you're solving somebody else's problem for them. They're going to reciprocate, and they're going to want to come to you to solve their easier problems when you can help them with their hard problems.

[Dr. Chris Beck]
I don't know about the rest of the audience, but if that doesn't get you excited about getting into this and knocking down some of the roadblocks and charging full steam ahead at lymphangiography, I don't know what it is. Good plug, I like that. Thanks, Bill. Anything that I didn't ask you, Bill, that we should have talked about? Don't get me wrong. I still think Backtable, we're still scratching the surface of this, and we're going to have a lot more episodes to do on it, but anything else left unsaid that you'd like to plug or talk about?

[Dr. Bill Majdalany]
As I say, the last thing that I'll say in regards to lymphatics is that this space has dramatically evolved in the last 10 years. We went from thoracic duct embolization, now we talk about hepatic lymphatic embolization, thoracic duct stenting, thoracic duct recanalization, trying to understand the pressures, using the thoracic duct as a way to decrease portal pressure in patients with ascites and variceal bleeding and understanding new diagnoses of this protein-losing enteropathy, protein alveolar proteinosis, plastic bronchitis, et cetera.

It's not just the iatrogenic leaks. It's all these other things that gets back to the lymphatics are interrelated through every organ and every circulation throughout the body. This is going to continue to evolve. At some point, I predict that we will have trans-lymphatic interventions for oncology. I do think that we will continue to understand the space of endocrine and how the lymphatics serve as a reservoir for hormones and understanding fluid balance in the body, and heart failure, and ascites, and how the lymphatics have an interplay with that, and the pressures. I think these are all things that are going to continue to happen.

[Dr. Chris Beck]
In your estimation, this is my takeaway of this, one, in our understanding of the lymphatic system, I don't know if we're at elementary school level, but maybe junior high. It's only going to continue to evolve if you're a young interventional radiologist looking to cut their teeth, or publish, or just develop a practice. This seems like green pastures, in my opinion.

[Dr. Bill Majdalany]
Absolutely. I'd say green pastures, blue water, I think there's a lot to do. I see, the group out of France did, [in their] JVIR article, measuring pressures in the thoracic duct pre-imposed stenting for patients with ascites who couldn't get transplants and were non-TIPS candidates, et cetera. How we could still help a third of them who are medically refractory resolve their ascites. This is dramatic. That is a new paradigm. Say, okay, I can't give somebody a TIPS. We all see this, oh, maybe their MELD is elevated or whatever. Understanding which patients to treat, which ones are going to have better outcomes than other is to me that next cool thing. How we can use that to change the course of patients who others would say, "Oh, hey, they have really terrible liver function." No one even thinks about intervening through the lymphatics, but it's there.