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So hello everyone. Er welcome to another episode of Ir Bites. Er Today we're joined by Doctor Kevin Fung, who's a pediatric interventional radiologist at Hong Kong Children's Hospital, the Tertiary Center for complex pediatric cases in in Hong Kong. He's also the honorary secretary of the Hong Kong Society of Interventional Radiology and he's very kindly taken the time out of his busy schedule to join us on the several seven hour time difference to give us an overview of the exciting stuff that he does as a pediatric interventional radiologist. Um ok, you can take it away. Thank you very much Dan and thank you for inviting me to give this talk. So I'm just gonna give a give an overview of what we do as pediatric um Ir so I often get this question um when I meet my friends or my parents. So what's a pe interventional radiologist? So that's what most people in Hong Kong think I do. They think I'm the radiographer to um position um kids to take images. My parents are a bit better. They think I look at xrays and you know, make diagnosis with my friends and my classmates think that I normally have a cup of coffee and just sit in the reading room and do nothing and my patients know a bit better. Um, uh, I, they think that I'm a clown basically. And this is what I think I do high end, you know, advanced, uh, interventional stuff, but mostly actually what we do is IRS or P IRS. It's lots of time. We're on the phone, we're talking to clinicians, we're talking to our nurses, we're talking to parents. It's a lot of communication, but it's, it's fun. So um a short glimpse of what we do as API R. This is mostly what we enjoy doing, which are procedures. So this is a cryoablation of a um kidney. And we, we get to see a lot of patients in the wards and that, that's actually a very rewarding part of being PT R. So this is me going up to the ward um to teach the nurses how to access a hemodialysis circuit in a kid. And we do, we do a lot of procedures with initiatives and that requires a lot of planning. So this is part of pr as well. Compared to Ir, we do a lot more planning, preprocedural planning and we communicate with, we have to communicate with the anesthetic team and do a lot of pre ir huddles. And this is actually a real life case uh where we did an intrahepatic lymphangiogram and we have to transport the patient under general anesthesia to the MR suite. So uh good communication is the key to make sure the patient and procedure is done safely. And of course MDT S, I'm sure you guys are all familiar with that. And Ir play a huge role in um the management and the discussion of NDTS and of course, I are, are fun loving people. And um this is one of our Christmas gathering in the IRC. So this is my hospital. Um I'm from Hong Kong and our hospital just started um operating in 2019 and this is where you can find us um in the old kayak airport. This airport has been demolished now and this is the classic scene of a plane landing in the old airport. So we're basically at the oil terminus of the old airport and we are the er tertiary center for the oncology cases, uh renal nephrology cases, complex cardiac cases and we do all the transplants in this hospital. So this is our radiology department. A Peds radiology department is obviously fun and we have a hybrid theater and we also have a by plane Angio Suite um inside our um in in our department. The good thing I in our department is that we are joint um diagnostic interventional radiology. So we can use the MR machines and their CT machines for procedures without having resorting to, you know, begging people to let us use their, use their machines. So the life of API R is a bit different from an adult. I I can see from our case load. We do a lot more lines, we do a lot more biopsies but there are also fun stuff. Um We do a lot of vascular anomalies that's quite rare in adults and we do some renal angioplasties as well as lymphatic imaging and interventions. So what's so special in doing ir in Children and what do we have to be careful or be beware of? Uh, well, that this is a really old saying, Children are not little adults. And, um, you know, us often we have to put in drips for or lines for really tiny baby, which is the size of my forearm basically. But it's not always true. Uh, perhaps right after this patient, I'll get this patient who's probably a teenager and she could, she couldn't even possibly lie on the CT gantry safely. So it's a huge range of uh patients in both age and sizes and, and it's really challenging and it's part of the fun of um, Pir so these four areas are how Children are special. Oh, so firstly, um, they need sedation, most of them need sedation, some form of sedation. Uh, they get quite scared when they get into the IR room and you want them to calm down so that you can do the procedure safely. And, uh, often we have to work with, um, anesthetist as sedation provider and sometimes pediatrician. So we have to balance this triangle. So it has to be safe and the patient would have to be at an adequate conscious level and he or she would have to be comfortable to undergo the procedure. So the anesthetist use all kinds of, you know, great medicine, uh propofol and fentaNYL and Precedex. But the key is to communicate with them to let them know at which point your, your procedure is gonna cause significant pain and they can up the level of the medication at the right point. And I always emphasize that using a good local wins half the battle because once you anesthetize the patient well, using local anesthetic, then the anesthetist can lower their uh intravenous medication level and will improve the patient's safety outcome. So this is how I inject the L A. Usually I infiltrate the skin first to numb the skin so that the patient is less irritable and then I will anesthetize the rest of the subcutaneous tissue. And using Emla is always a good idea. If you, if you're gonna poke, poke the kid, put the lar on, let it be for 30 minutes and that will numb the skin right away. And it's always very important to note the L A dosage, the local anesthetic dosage when you're dealing with kids because they do reach their max dosage quite quickly, especially in small kids. So this board is what we use in our department to make sure that we don't exceed the safe maximum dosage. And in Pir, it's, it's very interesting. In adult hospital usually you do a diagnostic scan somewhere and then the patient comes to you. But, but in a children's hospital, usually we do something called a one stop service. So for example, if a child presents with a tumor, then do the diagnostic imaging, the staging, the biopsy, the line and even the bone marrow biopsy all in one go under one sedation that minimizes the patient's number of sedation, it gets the diagnosis early and they can start treatment early. So thi this is part of part of the fun of it, I guess. Uh the second part is radiation dose. I'm sure you, you re you realize that uh radiation has a sto catic effect in ch Children and they may cause cancer. So uh there is this scheme where we say step lightly and be careful when you do fluoroscopy. We follow the alara principle in that we use as little uh radiation as possible and we child size the technique meaning that sometimes we remove the antis grid on the fluoroscopy machine to reduce the dose and think ultrasound or what Mr is more advance. But think ultrasound is actually a superb tool to um have a cross sectional view of the organs in Children because they're so small, the ultrasound beams penetrate really well. So there's a variety of ultrasound pro probes know your ultrasound well, if you can do the ultrasound. Well, you, you have, you have already one half the battle already. So I'm gonna show you a case. So this case is a case of biopsy of a 16 year old girl with an incident or superior mediastinal lesion. And this is the CT um if you want to have image guidance during biopsy, ultrasound, in this case is much better. I mean, this lesion is straddling between the left common carotid, the brachycephalic artery. If you do it under CT, you don't have real time guidance, you don't know where your needle is going. If you use an ultrasound, if you get your acoustic window really well, you can see your needle where your needle's going and that makes it a really safe way to do the procedure and contrast volume of fluid stasis uh status is also a very important point, especially in the small Children. Uh in a very young child, the main risk is nephrotoxicity and then of course, you can get allergic reaction. So there are certain risk factors in patients that would increase this. But in Children, the weight is one of the main issue. You have a very small child, very young child, their kidney functions have not been fully developed yet. So using contrast, uh we need to limit the dose to limit the nephrotoxicity. So how much is too much? So for a neonate, for example, we're taking 4 to 5 mils per kilo and a normal neonate is like two kg. So if you're doing an angiogram on a kid, 1 10 ML syringe would already be your total dosage. So what we do is uh we can dilute the contrast, we can do 11 dilution to try to increase the uh volume of contrast that we can use. But the thing is uh for example, for a two kg neonate, the total blood volume is actually only about 100 and 20 mil. That's half a can of soda here. That's one can, it's 330 it's only half a can of soda. So for so if you lose 10% of blood volume, uh or if you inject 20 mil of contrast, that's already um about 20% of the blood volume. So that's quite significant for a small child. So I'm gonna go through five areas for this tour because there's just so much to go through. So I'm, I'm gonna choose five of my favorite and I'm gonna go through, I'm gonna go through with you guys. So the first thing is biopsy boring, but it's essential. And if you do it well, your pediatricians will love you. Your pediatric oncologist will love you and the Children will love you because you don't have to subject them to another biopsy. So what do we commonly most commonly biopsy? So we have the focal lesions. So we have the sart tumors, uh neuroblastoma, hepatoblastoma, lymphoma, and then we also have the bone and soft tissue lesions. And then on the other hand, we have the uh nonfocal uh lesion biopsy, liver, kidney to get the parenchyma for a parenchymal diagnosis. So for, for focal lesions, for kids, uh we try to obtain as many core as possible. And up to when I was trained as an adult, ir I thought three cores was already a lot. But when I went into peds, they really test for a lot of things. Uh they test for the molecular profile, they test for the genetic profile and that all requires tissue. And you remember your competitor is the PEDI is a pediatric surgeon who can excise as much tumor as they like as possible. So, so we have to be as good as the pediatric surgeon in getting as much core as possible so that the pathologist can make the correct diagnosis and they can do all the genomic and molecular profiling which can then tailor the treatment for the child. So I always use coaxial biopsy. If you haven't seen this before, this is the coaxial cannula and this is the biopsy needle. So don't, don't assume that just because we're biopsying small patients, we're using small needles. In fact, uh I I commonly use um 18 or even 16 gauge for deep lesions. So, so for neuroblastoma, for example, and for superficial lesions, I use even large gauge size because I can manually compress and stop hemostasis and for bone lesions, I would use even bigger cause to try to get the biggest bite as possible. So this is what happens in coaxial technique if you haven't seen it before. So the coaxial uh cannula insert is inserted into the tumor and then you remove the inner ect and then you insert the biopsy needle inside the cannula, you grab your biopsy and then you repeat the procedure until you're happy with the number of cores. So the good thing with coaxial is a, you can do as many cores as possible with one single capsule puncture. Secondly, you can embolize the track with uh gel form slurry. So there's two ways to do it. Some people like to insert this gel form torpedo in the ST and some people like to use the slurry. I I prefer the slurry personally. So this is a, a case of using gel form embolization using the slurry. Uh You can see that we inserted the 18 gauge biopsy. No, for biopsying this liver tumor. And then once we remove the needle, we injected the gel foam inside the tract and completely uh occlude the tract. So that stops um any bleeding if there's gonna be any. So uh this is the bone biopsy drill that we use. Uh we use it mainly for sclerosic lesions. Actually, when the bone is really tough and hard to get through this drill is a lifesaver. Now, there are even more special needles uh I use this needle if I have to reach for really difficult and difficult places. So I'm gonna show you a video of this needle. So this is called the Gangjee soft guard needle. So it's got a spring loaded let and when you actually push it against something, if you're holding onto the ST, the blunt tip can be deployed and you can dissect through um tissues and not curse it during the process. So, for example, in this case, when you're trying to go to a very deep lesion next to the colon and the, and the um uh the k the vessels. So when you try to pass the gang needle, if you hold on to the blunt tip, stilet, now because you don't want to injure the colon, you can just dissect all the way along and go to your target and then release the stilet and use the sharp end of the coaxial needle to enter the lesion like that. And this is a in vivo test on a pig model. So this is your normal diamond tip meter. What will happen is if you transect the vessel, it will just sped like that. But if you use a Gai off guard, and if you deploy the blunt to let when you're going across the artery, you would just sort of displace the artery and not really hurt it. So the arteries is not really hurt here. You can see it just sort of displaces the vessel nicely. Right. So this is a case on um uh uh uh in which I chose to use a gang needle to try to get to this lesion for biopsy. So this is a nine year old girl and she had a history of med blastoma and had chemo RT and they found this C 12 lesion here. And you can see that this is the internal carotid artery and this is the vertebral artery. So they want to get some tissue. And I was like, oh God. Um so how we're gonna do it? So this is the ct of the lesion and this is the ultrasound. You can see actually you can see very well the viste artery and the IC. So we use a ganges off guard needle under ultrasound and we de we sort of deploy the blunt end in case we hit any arteries. And you can see that the needle actually just goes through the gap of the IC and the vertebral artery and went into the um went into the lesion safely and pathology came out to be um PV NS surprisingly. So this is, this is one of our more difficult biopsy cases. So going on, um this is a second part uh of pizza, that's the bread and butter and super important is to get into access into the veins. Yeah. Uh it's different from doing adult line. Uh When, when I receive a line request, I always study it carefully and I'll ask myself several questions. So what kind of infus does the kid need? Does she, does he or she only need uh a short term antibiotic course for a few weeks or is this gonna be, you know, for chemotherapy hematopoietic stem cell transplant? Which means that the kid would need really, you know, several years of that line or even worse if it's gonna be a case of hemophilia or metabolic disease, the need of a line is probably lifelong or short gut patients really need the line for lifelong. So think about that, you the expected duration of the line and you got to think about long term in kids. They're not like adults. I mean, if you put a line in the internal jugular, if you put a long term line in that line might be lasting him or her for 10, 20 years easily. So you want to preserve as much vein as possible. Think about which vein you're gonna use. And when I first started with vascular access, I always find it overwhelming. It's like going to supermarket. Everything looks the same, but it's slightly different. So you've got lots of choices. You've got the sh you, you've got to make the choice of putting in a short or long term catheter. And then you've got the choice of the PSEC versus a central catheter versus ports. And then you've got to choose which vessel to put it in and you also have to think about, do you want to tunnel the line or do you not want a tunnel line? The good thing about having a tunnel is that it prevents bloodstream infection uh more effectively. Uh If you, if you, if you dissect a subcutaneous tunnel, so the, so I'm just gonna show you a few examples of the uh if of the catheters, if you're not familiar with them already. So we have the temporary lines. This is your most vanilla sort of temporary cent we call it central lines basically. And then you have the temporary hemodia catheter. The hemodia catheter have larger lumens. You can see that uh it usually have a blue lumen for drawing venous blood and a red lumen for pumping in uh pumping in back the hemodialysis blood into the patient's body. And then for the long term ones, you've basically got four choices. You've got the PI CC S your peripheral inserted, central catheters, you've got your ports. So these ports, the part of the port gets implanted inside the patient's uh subcutaneous tissue and you need a special needle to access them. And then you've got the tunnel cuff catheters. So they're tunneled and they have, there's a cuff in the, in the central venous catheter to prevent the child from tugging it. Um and dislodging the catheter. So, fibrous tissue will grow around this calf and uh it will secure the line and same for the long term Mois catheter. It is basically a tunnel cuff version of the uh of the temporary catheter. And you've got a lot of different um end configurations for the cat to end. So there's these split ends and sometimes you've got the tapered ends. So ba basically what you'll see, you'll see two lumens, two distinct lumens, one for drawing blood and one for pumping it back in. So, uh this is one of the decision support algorithm that I I use. Sometimes uh if I've got problems to decide which lines to use, it's developed by a um a group of uh line expert nurses. So it basically tells you if you've got a certain scenario and you're gonna think about the, if the infus say is peripherally or non uh peripherally compatible and you're gonna think about the line duration and then it sort of suggests uh what is a good line to use in your situation. Now, choosing the right vein is very important. Uh The number one rule is use the smallest device in the largest vein. So the reason for that is you don't want to occlude the vein and you don't want the vein to thrombose. So for example, for API CC, I would go first for the basilic vein because it's most superficial and it's usually the largest and most well developed. Secondly, I might go for the cephalic but in small Children you'll see in a minute, the cephalic veins are not well developed. So they, they undergo spasm easily and you may have difficult threading your catheter in even if you can get access, brachial is deep and it's uh close to median nerves and brachial artery. So I usually avoid that if I can and for central venous catheter, uh I would choose internal jugular first before I go for femoral. Uh reason being the neck is usually the cleaner vein. So the second thing is you, you want to choose the right device. So what's the optimal catheter to vein ratio? So basically the sort of rough thumb is half. So uh you know that a three French catheter is one millimeter. So if you have a two millimeter vein, the maximum uh catheter size would be a three French catheter. But you also have to take into account what the patient need. So if the patient needs multiple inflate and they want to put in a double lumen line, it's no good putting in a single lumen P IC C for them because obviously they then would need to access another vein to to get um another line in for this for the other infus state and kid vein, they're difficult, they're small. Uh This is one of the larger veins actually, uh two millimeters, they get difficult to puncture when they get less than two millimeter because they sort of float around. So uh choose your ultrasound for it wisely, I always use a hockey stick because the footprint is small and it sort of has a very high resolution. So you can, so you can see everything very clear. You really need a very good ultrasound machine to see where your needle is, see where your vein is and uh know your access needles well. And uh obviously for different age group, we use different access needles. So this is a 24 gauge um angio catheter and I use that most commonly for a small Children uh for for veins less than two millimeter, a 24 millimeter angio catheter works like one does. And we also need to know with this access needle what wire you're gonna use. So for this different Angio catheter brands have different um uh wire size. So the in in the lumen is different. So the wire combo is different. Uh I basically, I would try it out first before I actually try it on the patient because once you get access, everything happens very quickly and you need to get the right wire in. So sometimes they come in a set. So this is a micropuncture, four French micropuncture set. So this comes in a set. But for example, if you're using Angio catheters off the fly, then you really need to try out. So always have a plan, choose the best looking one and have another one that's back up. Cause if one fit once you puncture it and it starts having a, it's, you start messing it up and it starts building a um perivenous hemato hematoma up and it gets difficult. So have another vein is back up and usually work your way up. Cause if you blow up the vein up here and the downstream vein might get, might get affected and you may have difficulty throwing a wire up. So, uh two major ways to do uh well, always do it under ultrasound basically, but there's two ways to guide it. So you have the longitudinal section and then you have the transverse section. So the good thing about the longitudinal section is you can estimate how deep your needle is going. And you can visualize your whole needle in one single path. I usually do this for larger veins. Um I I love seeing my needle the total the my entire needle in plane. But if you look at the intensivist and you look at the Anestis, they like to do it in the transverse fashion. Um Well, each has their own benefit. Choose the com cho well, basically learn both methods and choose a method that you're most com comfortable with. So for veins less than three millimeters, I would actually use a transverse approach because the vein, the the kid has really soft and bouncy soft tissue. So when you try to in in insert a needle or puncture the vein, the vein actually just slides away. So what I do is I, I look at the transverse and then you dart it, you, you, you might even double puncture it and you slightly pull back so that the Angio, the lo the cannula of the angio catheter would slide back into the vein and then you would get back flow and then you do your wire access. So kiddy veins like kiddies, they're not fully mature. They like to go into spasm, they're shy just like kids. So handle them with care and don't inject too much L A around the vein. Uh don't inject too much local an SS around the vein because it, it will cause spasm and it will make your puncture more difficult. So this is another area of bit controversy which is the catheter tip location. The proper location would be at the SVC right atrium junction and on the x-ray, it would be about 1.5 to 2 vertebral levels below the carina. And that's your perfect level. And for hemodia catheter, they need a larger uh volume for exchange. So they usually put it in the right atrium. So be careful for catheter tips for P IC C, they're actually dynamic. If you put the patient's arm up or down, that can be, that can make a big difference. It doesn't make a big difference in an adult because the SCC is so long. But imagine in the three year old or four year old, the SVC is actually only five millimeter. So when you're moving the arm up or down. That would already be a two M two centimeter difference. So that makes a huge difference. And if you have a sedated kid in your lab and everything is going well and when they go back up to the ward because they raise their arm up and the catheter flicks back up, uh it, it, it, it can cause trouble and you, you have to call patient down again, obviously to readjust the catheter under anesthesia. No one's gonna be happy about that. So uh special circumstances call for special um lines. So for example, in this patient, you can see that the SVC is obstructed. So what we have to do is we have to think out of box and do a tunnel cuff femoral line instead. Uh that this line actually has a similar efficacy as your tunnel neck Hickman's. And as I've mentioned before, this is a a cephalic vein poetry. You can see that the cephalic vein is actually very spastic and they go into spasm very easily. Um Even if you get access, it's difficult to put a wire in. We're lucky. In this case, we're able to put a 22 kg liter flex in. So we have different techniques for kids who needs larger catheters because obviously a 22 K liter flex is, is is a really small lumen is just about two French. So uh this is called a single stick tunnel technique. So we use the micropuncture needle and create the subcutaneous tunnel in one single stick. So there is a tunnel here already. And you can see that the tun the catheter exercise is actually below the di line. So it's fairly clean. So we can actually do it this way uh to do a sort of clean femoral line by doing a single stick tunnel technique. And this is even slightly more advanced. So this is single stick um neck. But in in, in doing this, you have to curve your micropuncture needle and insert it under the ultrasound in a curve fashion. I I this is more tricky because you're not visualizing the whole needle in one go. So um catheters can malfunction. These are the common reasons. The first ones most scary catheter breakage, actually, um you have to snare that back out uh and satisfactory tip position. A chest x-ray will usually sort that out. So I'm gonna talk about fiber and sheath because you can't see those and people get quite confused about those sometimes. So this is what happens when the catheter gets left behind for too long. The blood has a lot of fibrinogen and it sort of gets stuck onto the catheter. So it creates a sleeve around the catheter. So when you inject the sleeve actually opens, but when you try to aspirate the sleeve clamps down on the catheter. So the classic symptom of a fibrin sheath is you can inject but you can't aspirate. And when you do a lino gram. Uh You can see that the contrast just outlines that fibrin sheath coating. And in, in really bad cases, it reflux back along the tunnel and you would have contrast seeping back out. So how can we deal with these fibrin sheath? So obviously, you can try to lice them with fibri or you can try to strip them with a snare. Basically, you snare the catheter and you try to just pull it and try to strip the fibrin sheath away. And you can see um that line uh the contrast is now flowing through right atrium beautifully. Or you can exchange the line with a sheath and then put a balloon, put an angioplasty balloon in and try to disrupt the fibrin sheath. And again, you can see in this line uh this was the fiber sheath and then after disruption, the contrast is fanning out much nicer. So moving on, uh this is gonna be third part of this um overview. So, renovascular hypertension again is one of the common, this arterial intervention that we do in Children. So, fibromuscular dysplasia is one of the most common cause. And it's, it's because uh of abnormal musculature uh inside the renal artery. So the treatment will be angioplasty. So you do a balloon angioplasty. Uh when do we do it? It's not totally evidence based in Children. Uh But if we have a child with resistant hypertension, uh despite going on, you know, all three drugs, we try it or if the child has um side effect, a lot of side effects from the drugs. And we will also do renal angioplasty. And the last scenario is if you have a case of bilateral th muscular dysplasia or unilateral th muscle dysplasia in a single kidney, you want to save that kidney and you want to save the function of the kidney. So what's so special about doing renal angioplasty in Children. Obviously, their vessel is small. You can see this is a five inch guiding catheter, which is about 2.7 millimeters already occupying your entire um renal artery. So it's it's um the instrument is difficult to get and you have the contrast dose limitation uh small profile device. So we often use actually, we often use coronary devices, adult coronary devices. The size is similar to that of a child's kidney, getting arterial access is difficult and managing the arterial access afterwards is difficult. So you have a two year old kid. After you remove the sheath, you want the kid to stay still for six hours. No way they're not gonna do it. So sometimes we have femoral casts to keep the child um stable for a while because these childs have to be on heparin as well for a while. So you really don't want the groin to bleed out and uh in front of muscular dysplasia, angioplasty is the way to go. Don't use stents. The kid's vessel will grow. And if you use stent, the stent will be undersized uh for the child's um adult science vessel. So this is angioplasty prior and then after. So you can see we restore that um that area of occlusion beautifully. So this is another case, this is a case of mid aortic syndrome with a left um arterial renal uh stenosis here. The problem is if we go from below, it's very difficult to engage this um left renal artery, you can see here, the angulation is horrible. So what can we do? So in adults, um there's this trans radial as um fad and we, we did this case under trans radial. Actually, we did it via this stuff box approach. So going from above is a much easier way to get across that stenosis because everything the angulation is perfect for doing this case. And this is the end result. So you can see with trans radial access. Um after removal of the um of the occlusive device, the wound is actually extremely minimal. So the fourth part is actually this is my, this is my favorite part and I I do quite a lot of this and this is um one of the hot topics in IR at the moment, which is lymphatic imaging and intervention. Kids get a lot of those but a little bit about lymphatic. Uh If you don't have any uh background of it, the lymphatic system is is often called the forgotten circulation. Uh but actually, it has a super important role in maintaining your fluid balance. It's a vital part of your immune system. And when you, when you eat and digest food, all that fatty acid gets absorbed into the lymphatic system first, before going back into the venous system. And also the liver, actually, most of the liver proteins that synthesize has to go through the hepatic lymphatic, go through the lymphatic system before getting dumped back to the bloodstream. So that's, that's uh a super important a uh area. So how do Children get conduction abnormality in the central conducting lymphatics. So, obstruction is a main one. So how do they get obstruction? So for example, if they have prolonged line access and if they have occluded, bilateral internal jugular, that's one of the reason why they would get lymphatic hypertension. And this kind of lymphatic hypertension will backflow and cause all the abnormal symptoms. So, they have chylothorax, they can have classic bronchitis in which they cough up a bronchial casts, they can lose the liver protein through the bowel because it's basically a reverse flow. So everything should flow back to the venous system. But in protein using enteropathy, it just flows back into the bowel and you can have call ascites. And of course, you can get lymphedema if you get lymphatic blockage. So the other reasons kids get this kind of abnormality is if they have cardiac surgery, if they have something called a Fontane operation. Uh The venous pressure is extremely high and that would also cause lymphatic hypertension. And then you can have congenital absence or genetic alteration causing abnormal uh lymphatic proliferation. And that would cause um multi compartment lymphatic flow disorder. So there's several access point where you can get into the lymphatic system for imaging, for intervention. So remember, there's three major compartments. So there's the truncal compartment. So your limbs and then there's the liver compartment, which is the liver. And then there's the mesenteric compartment. Why is it important is because we have to understand the an in the anatomy and physiology to to get to the right point for access. So if we wanna access tracor and lymphatics, ultrasound is the best uh sorry. The inguinal no is the best place to do it. And we usually do it under ultrasound gup puncture and we uh put it, we hook it up with a lipo pump and this is what you're gonna see in a lio lymphangiogram. So when do we do a truncal a? So if the patient simply has chylothorax or plastic bronchitis, the lymph flow goes up like this. So when you're imaging it, you can actually. So for example, in this case, this is just a Trunkal injection. So you can already image the chylothorax here. And then you can also image the um thoracic duct venous angle where there's obviously lympha ectasia here. But if you are suspecting Caci's protein losing neuropathy or multi compartmental leaks. You really have to get access from the liver or even the bowel to really to, to visualize the um lymphatic leak from there. And this video will show you why. So if you just access from the truncal region, you will bypass the liver lymphatic and you won't be able to see it. So you really have to put your needle in the liver to visualize how that lymph flow is being dumped into the duodenum. So I'll show you uh a case here. So if you inject, so if you puncture a needle into the lymphatics in the liver, and if you inject me fine in blue, you will actually show up in the duodenum. And that would cause protein using enteropathy because you remember what I mentioned, 60% of the protein synthesized by the liver is actually transported by the lymphatic system. And this is one of our cases, we uh puncture the hepatic lymphatic and you can see that this pattern is actually the duodenal fold. So this is going like going down and if we were just injecting tranquil, you would miss this part entirely. So this is a um dynamic contrast injection of Mr contrast. So when we inject contrast via this needle here, you can see that contrast spills into the duodenum and of course, it also goes up, then goes up into the thoracic duct and there's a huge mass in ventas here. So why is it important to image it? Because how to intervene, depends on the cause. So if it's a simple traumatic chylothorax, thoracic that embolization will work, you block off that uh leak physically with coil or glue. Uh If it's a nontraumatic lymphatic flow disorder, then obviously, you need to be more selective. You don't want to block the thoracic duct off. If you block it off, then it's gonna make things even worse. You can imagine if you try to block this channel off here, then all the lymph would then flow back into the stomach and the uh bowel as well as the uh proton cavity. So it would convert a chylothorax into a massive clos societe and a lymphatic diversion therapy. So you can do veno plasty if there's venous obstruction or you can do well not you. But the surgeons can do medical surgeries to connect lymphatic channels with venous channel, so called lympho venous anastomosis. And if we can identify certain targets, we can use medical therapy uh to try to reduce the lympho Gees. So this is a thoracic dut embolization in this case, from do I? So this is the CK and we basically use a cheer needle under fluoroscopy to access this exter high. And then we put a wire in, you can see the leak here and we use coil and glue to obliterate this segment. This is um the basics of thoracic duct embolization. That's what we do. Uh So this is another thing what we can do. Uh if there is uh a lot of um lymphatic leakage from the hepatic system into the duodenum, we can inject glue into the system to try to block off these lymphatic channels and block off the uh lymphatic leakage into the uh Duden. So the last bit of my talk is gonna be on embolization. So obviously RT embolization uh you, you, you know, there's a lot of um emergent or elective indications for it. Um for kids, mostly uh like adults, we use it to stop acute hemorrhage, we use it to reduce preoperative bleeding. Uh We have chemo embolization for Children as well and we use embolization to arrest high flow situation in certain, in certain situations. So there's a lot of weapons. I'm not, I'm not going to go through them because that deserves elect on its own, which embolic to use in what situation. But I'm just gonna show you a few examples of what we can do in kids and what we have to worry about. So, uh this is basically a kid version of and rupture HCC. Uh Hepatoblastoma is one of the most common liver tumor in Children and they can rupture and this is a case of rupture. Um hepatoblastoma, you can see that the bag is uh for fresh blood and this is the angiogram at the left hepatic artery. You can see all these abnormal pseudo aneurysms from the tumor So we basically used um eg gel. In this case, ed gel is calibrated gel form particles. So you don't have to precut them, you just mix them with contrast and you can, um, and they're bio sob. So, uh they can, the arteries can be recanalized in the future if you, if you are gonna use chemotherapy and this is a case of a massive thoracic tumor and they were planning surgery and they're really worried about this right bronchial artery here. So, what we did is we went in this is a right bronchial artery injection. And you can see all this tumor vascularity here. So we basically just deployed some coil and eg gel and you can see that this is the post angiogram. It showed much reduced uh tumor vascularity and the surgeons can get the tumor out easily without too much bleeding and chemo embolization, not just for hepatic tumors. And this is a study I joined uh for desmoid fibromatosis. So, desmoid tumor, if you're not familiar with them, they are, they are more like fibromatosis, they're not malignant tumor in the sense that they will metastasize. But if you try to remove these tumors surgically, they will recur 100%. Even if you get a clear margin. Most often, you can't get a clear margin. But even if you can get a clear margin, almost 100% they will recur and they will become much more aggressive. So they're extremely difficult tumors to treat. Um So there's several ways to treat it. Ablation, cryoablation is one chemo embolization. Uh is another option if you have a really extensive tumor that has, that is encasing a lot of critical structures. So this is a patient that I treat. Uh he's got this extensive desmoid in the uh in the left lower limb here. And you can see after four courses of treatment, there is still significant asymmetry but the tumor volume has shrunk about by half. And you can see all these black area is scarring. Uh It's the, it's the tumor scarred down after the chemotherapy. So, um this tumor is encasing the sciatic nerve. So definitely surgery is no go and it's too extensive and uh it's encasing too much structures for using cryotherapy. So this is another case, another challenging case where embolization really can make a difference. This is a zero day old neonate and you can see the heart is massive. And if you're not familiar with looking pes x-ray, there's a huge mass here and there's calcification. And this is the CT and you can see all these peripherally dilated vascular spaces with a central scar. So essentially, and this is 3D reconstruction. You can see that massive hepatic vein going. So this is a very high flow vascular tumor. This is a congenital hepatic hemangioma. And this is basically a super high flow tumor. And you can imagine all that flow being dumped back into the heart and it will cause heart failure and the child would die from heart failure if you don't arrest the flow here. Um quick enough. So what we, what we're gonna do is you can see that because of the high flow situation, the celiac artery is actually massive, but the femoral artery is so small. So how are we gonna get inside the femoral artery and get into these celiac arteries for embolization? So, this kid has a umbilical venous catheter. If this kid has an umbilical arterial catheter, actually, it will be perfect. And we can just swap the umbilical arterial catheter into the aorta and swap it with a sheath. But unfortunately, this is not the case. So we've only got, we only left with the UV C. So, what we did was this is the umbilical venous catheter. And we basically wire down the right ventricle the pulmonary artery and go through a structure called PDA, which is the ductus arteriosus. If you remember your embryology, and this is where embryology really comes uh becomes important. So, this patent ductus arteriosus connects the pulmonary artery and the aortic arch in the fetal circulation and it provides a communication between the venous side and the arterial side. So, if we can put a catheter down in here and we can reach the celiac artery. So this is what we did. So essentially we exchange the umbilical venous catheter with a five French sheath and we use a four French a catheter to go down this route, so called the up and over route. So these are the videos. So this is the wire going across the ductus arteriosus here and going down to the aorta. And once we got the wire down, we thread the catheter in and follow the wire down all the way to the celiac um Archey. Yeah. And then we did our angiogram and you can see this super high flow tumor going into the uh he left his pan thing. So once we manage to get in, we put in loads of coils. And this is the check angiogram to show there's still vascularity. But the aim is not to totally obliterate it. It's just to close off the larger shunt so that the child's heart is not under so much pressure. And you can see on day two already, the heart size has shrunk almost by half. And this kid is finally um she survived actually. So that, that, that shows you how embolization can really be a life saving measures in this scenario. So what I've shown you was only a tip of the iceberg of what we do as pizza R if you, if you're a Cerci member, uh you can go to Cerci Libre, there's a really nice pizza package and you can see, you know, I've only covered venous access and there's so much more in Pzir that we do and we can do. So please do, do have a look at this. And if you want to join PR, there's a lot of, I'm, I'm sure in UK there's, there's B SI R, ah, and they have API R interest group. Um, and they have, I think this year is the first year that they have an, an scientific meeting, which is great. And also, um, there's the SPIR, which is a society of pediatric interventional radiology and they have their annual meeting usually one year in the US and one year in Europe. And that this is a great way. This is actually how I met most of my pizza, our friends. Uh because there's not many people doing pizza in Hong Kong, it's a great way to meet people and learn about new stuff. And if you wanna come to Hong Kong to join us and see for yourself what pizza is about. Uh You're more than welcome. And uh we, we have a, we have a great program. Uh We welcome serve and attachments. Uh You can contact me via here, of course, in the UK, there's a lot of opportunity as well. There's the Great Ormond Street. Um and there's Leeds, children's, there's Birmingham children's. And um so if, if you have any questions uh about PTR, you're very welcome to contact me. Thank you. Thank you so much, Doctor fan. Um That was a fantastic talk. Um And you know, give a great overview of, of what life's impedes. Ir is like, and I'm sure we have inspired um a lot of people interested in IR and impede ir. Um Just, just a couple of questions. So you, you've already made sort of a compelling case for why Peds Ir is so interesting and sort of your day to day. Um Job is so interesting, but just to summarize why, why would you encourage people to pursue a career in Peds? Ir? And if you could just touch on your journey to becoming API R, was it something that you'd been set on from early on in your radiology training? And how did you, you reach that point? That's very interesting. So actually I started off as a pediatric radiologist and I did a bit of IR training and because we don't have a formal PT R program in Hong Kong. So my background is that I trained as a pediatric radiologist. But when I did, Ir, I actually found that super interesting. So when I joined this new hospital, the Hong Kong Children Hospital, I decided that I want to start a PT R program because there's there's no such thing in Hong Kong at the moment. So our hospital is the only hospital providing a comprehensive pr service. So um there are actually several ways people join P SI R. So we you can do it via what I did, which is the pediatric radiology way because the Peds disease spectrum is so different and you really have to have that, you really have to like kids to like peds ir uh it's, it's a lot more patient contact I find compared to adult ir and it's, it's great you get to see the patients and uh you know, the, the neonatal embolization case I showed you uh the, the case has been staying in the N IC for several months. And when I first did the case, the baby was really hydropic edematous. And one day when I was doing ultrasound round, I was doing my diagnostic round in the N IC. Uh A patient. A well, a parent sort of tapped my back and says, oh, say hello to this dot So I'm like, who's that? Uh And then she's like, oh, don't you remember me? I'm, I'm the neonate that you em, you did the embolization on, I'm like, oh my God. And she looks totally well and totally different and, and that's what's so, so fun and it, it really brings joys to your heart when, when, when you see cases like that. So that's what Pir, that's what pr is to me in my heart. That's great. Um Another question. Do you find it nerve wracking, performing procedures on such small patients? And how do you go for that? Yeah. Um It's part, it, well, you can say it's part of the fun. Um But yes, for sure. Um Doing what, what, what I find very helpful is um rehearsing the case and doing all the huddles because usually, um when we do, you know, um complex cases like this, we always have to involve the anesthetist. And sometimes, for example, with the neonatal embolization, we involve the cardiologist as well. They helped us go across the s arteriosus and it's always helpful to have platform to talk about complex cases with. So I find s pr extremely helpful uh they have these online forums and um there are a lot of experienced Pir there. I I often throw my questions up there because you know, it, it's nice to, it's nice to talk to people about um cases and bounce ideas off each other. But rehearsing the case is, is very important and making sure uh your contingency and backup plans are in place in case things go wrong. Um Yeah, try not to freak out and have a backup plan in place. But yeah, usually after those cases, um my shirt under the le A print is usually quite wet. Brilliant. Um And finally, just are there any sort of big developments in Pir um that we can look forward to in the near future? You spoke a lot about sort of lymphatic work and that's really exciting what kind of other um things are in the pipeline. Yeah, I think, I think lymphatic is coming along. I one huge um portion that I haven't touched on in this talk is vascular anomalies and that is actually a majority of our practice as well. So that deserves a talk on its own uh because it's, it's so complex. Uh But uh p makes a huge difference in vascular anomaly and there's always new therapeutics getting out. So, for example, for arteriovenous malformations in, in the peripheral system, um before we, we rely a lot on embolization to try to um eliminate the ni to try to eliminate the HYO component. But now we're bringing up Bleomycin, um which is uh a chemotherapeutic agent, but actually it has a lot of um it, it, we don't actually quite know how it works yet, but it reduces the vascularity of arteriovenous malformation a lot and it's a much low risk procedure. So, and then there's electro bleomycin therapy in which they try to mix electric current with bleomycin to augment this effect. So, these are some of the new toys you can say that we have in Pia that can, that can quite make a difference. That's great. That's really exciting. Brilliant. So, thank you once again for joining us. Er, we really appreciate it. It was a, a really inspiring talk. Um So this is I think the penultimate episode of um Ir Bites. Er, we've got one more left before we um we take a break. Um So, yeah, thanks again, Doctor Fun. Um We'll stop there. You're very welcome, Dan. Yeah. Thank you. Thanks for reminding me.