Dr. Riyaz Bashir, Director, Vascular and Endovascular Medicine at Temple Health explains the applications for Balloon Pulmonary Angioplasty, or BPA. BPA is a minimally invasive treatment for certain patients with Chronic Thromboembolic Pulmonary Hypertension (CTEPH), Chronic Thromboembolic Disease (CTED), and lingering Pulmonary Arterial Hypertension (PAH) after Pulmonary thromboendarterectomy (PTE) surgery. To date, Temple has conducted more than 257 BPAs.
Uh So, so the question is why balloon pulmonary angioplasty uh in in patients with chronic thromboembolic pulmonary disease, then you can do a surgery that is like this. You know, you can take out literally everything out of these pulmonary arteries and patients pressures will normalize. And this is essentially a curative therapy for for these patients. Uh So why balloon pulmonary angioblast? So here, here is the reason 57% of the patients uh you know, who are operable, get actual surgery and one third of the patients or 36% of them are inoperable. So essentially, you're left with half of the patients not getting a definitive surgery for their disease. And those are the patients, they become the candidates for balloon pulmonary andro blast. The other group of patients which is becoming increasingly more common is patients who have had pulmonary thromboendarterectomy like this young gentleman who continue to be symptomatic and have significant residual or what's called persistent pulmonary arterial hypertension after thromboendarterectomy. So, this is another indication for doing balloon pulmonary angioplasty. Uh This this field um was initially uh started in 2000 from um from Brigham and women's hospitals, pediatric uh group uh that reported their experience with 18 patients of balloon pulmonary angioplasty. And uh there was a very high rate of mortality and there was a very high rate of reperfusion pulmonary edema in those patients, 16% of those patients died. And so nobody started, nobody did this in in us because of that experience. Uh it was however, in Japan where surgery was not very frequently offered that these patients uh were getting balloon pulmonary angioplasty. And most of this experience to date has come from Japan and recently from Europe. So what the Japanese experienced was that their survival was significantly better than patients who got just medical therapy. Their uh mean pulmonary arty pressures improved, their cardiac index improved their PV R dropped and so did their biomarkers. The only thing that was a little different in the Japanese experience was that most of these patients, the Japanese operators did balloon Pulmy angioplasty. Uh US operators would actually do uh PTES on them would do surgeries on them. So it's a little bit different uh uh demo uh you know, patient phenotype. So one thing that has been consistently shown is that the six minute walk distance increased and this is the European experience again, showing improvement in survival. Now, what the way the field has evolved over the last decade is that if you have what's called the level one disease or a level two disease, your first line therapy should be pulmonary thrombo opery surgery. And if you have level three or level four disease where it is far down into segmental arteries and distant segmental arteries and, and sub subsegmental branches. And those patients should be considered for balloon pulmonary angioplasty. That is an assumption that that these patients do not have level one or level two disease. So if anybody has level one or level two disease, they get uh pulmonary thromboendarterectomy. First. Did anybody have a question? No, sorry that the machine, it was just me logging. Ok, no problem. So uh the challenges, what are the challenges for balloon, pulmonary angioplasty? You know, these are the coronary arteries on the right and these are the pulmonary arteries on the left. It's like a forest there. It's there are so many branches that come off at the same spot you just have, you know, you just don't know which branches you are in and, and a lot of these branches have osteo occlusions. So you may treat two or three branches, but the 3rd and 4th branch you may not even see. So you don't even know there is a branch there. So, so that's one challenge of pulmonary bone. And the other uh challenge is that these uh vessels are relatively thin walled compared to other muscular arteries in the body and they can easily rupture. Uh just like this patient. Uh you can see the rupture here and, and uh ase aurm there. Uh a lot of these patients have significant uh pulmonary hypertension. And when you open that vessel, all of a sudden an velar vessel which is literally hanging in the air, these Alvear vessels, there is very little tissue there to support them. And you know, if a patient's cellular pressure is like a vege tracing before you balloon, it, once you inflate the balloon, all of a sudden, this pressure can go significantly up and that's what leads to reperfusion, pulmonary edema, which is essentially bleeding into the alveolus. Um And, and that's, that's the, that's a huge challenge in in treatment of of these patients. And they have all kinds of different types of lesions. This is not an atherosclerotic disease where you have a very focal discrete atherosclerotic lesion. Here, the lesions are of all different types. You can see a vessel abruptly narrows and then there is nothing else going beyond there. You can see Luminal irregularities. You can see you see this here, there is a little bit of illuminary irregularity. You put a pressure wire down there, there is a significant drop in pressure. There's a vege tracing here. You can have these webs and bands in these vessels and becomes challenging to, to cross those. And you can have a pouch, you can have a pouch defect, right like this and you can have total inclusions. You can see there's a total inclusion right here. And uh other challenge in these patients is you may have a vessel like this and it has webs like this in it. And the moment you cross it with a pressure wire, this is the gradient you're going to see. But if you just went by and geography, you will say that this looks great. There is no problem in this vessel. So that's another challenge. The uh and geography may not be able to uncover all the legions that you will, you will see and you can see this is an oct of this legion. You know, you're not sure whether there is a legion there. But when you do an intravascular imaging, you see that it's full of, of recanalized traumas there. And, and this is the pressure tracing beyond it. And, and the other challenge in these patients is there is very little room for the vessel beyond the legions. Since balloon angioplasty is done on legions that are level three, level four. Sometimes you don't have enough room for the wire to be there. And, and the balloon is close to the radio opaque part of the wire. And the other uh challenge is when you know, these patients are awake and they're breathing and when they take a breath in it moves your vessel up and down like this. And, and that makes it very challenging to, to wire a total exclusion that is austerely occluded. And it also makes challenging because your equipment moves. Uh So he here is an example of a 47 year old gentleman. He is a self-employed painter from Wisconsin. He had splenectomy and you can see his right lung is having significant perfusion defects. And when we got him, we did a pulmonary angiogram. And you can see he has no proximal disease, but he has perfusion defects. And these perfusion defects are what is causing his symptom. He basically had to stop doing his job. He, he closed his business because he, he couldn't do the job. And so what what we got him is we got him. We did selective angiograms. And you can see the lesion here, you can see the lesions here lesion here, lesions here and and here and here. So, so we treated all of these lesions with the pressure wire guidance. So the way we do it is we take, we go from usually from a thermal axis, we put a long seven French 70 centimeter sheet and you can see that sheath tip is right here. And then we take a guiding catheter, a multipurpose or AJ R four or an A L one guiding catheter depending on which vessel we're treating. And what we do at temple is we usually cross these lesions with a rady wire, at least that's our first wire to use. And then we balloon, dilate it over, over a radi wire. So the goal is that you don't want your distal pressure to be about 35 millimeters of mercury mean. So here is how the pressure wire will look, this is the pressure wire tracing the blue one proximal to the lesion. And this veg tracing is when you are beyond the legion. So when you are not sure where the lesion is, you can pull this wire back. And the moment you are inside the lesion, the wire, the pressure becomes ventricular. So you exactly know where your lesion is and why you have to dilate. And once you dilate, you convert this vege tracing into a pulsatile tracing. And your goal is to make sure that this distal pressure stays less than 35 millimeters of mercury because that's when it is associated with higher risk of reperfusion, pulmonary edema. So the other thing is how do we, how do we deal with the with the breathing issue? So you can see when you are, when you are not taking a deep breath in these vessels look very tortuous. Now, when we take a deep breath in, it stretches these vessels and that's when it becomes easier to cross these vessels. So, so we use breathing literally when we have to cross the vessel. And you can see this is how this vessel looked. And once we were able to cross the lesion with, with a deep breath in and this is how it looks. So breathing is, is a big thing in balloon, bone angioplast. And so we ballooned. So all literally, all of his lesions on the, on the right lung uh for this painter and, and this is this perfusion after balloon andros. So this was before and this was after and this is his VQ scan a month later. So you can see the difference between this and this. And he basically was able to go back to his work, started his business again and his paintings now uh so his six minute walk distance was 360 m. His PV R was 6.8. Now it is 449 m and a PV R of four. And you can see his right ventricle is much smaller. Um So here is another example with an abrupt o collusion, you know, you are able to cross this, you dilate these vessels and you can restore perfusion to these LVO. I uh here it is a web. You can see a tight web. This is a pressure gradient across this web with the pressure wire and you dilate this with a balloon and you basically normalize this this pressure beyond that. So the other thing we have learned over the years is that when you have total collusions like this, and you basically restore one blood flow to this vessel. And what happens is that these vessels remodeled over. So this is I'm sorry, this is a month later. You can see how big this vessel has gotten because there was a flow restored into it. And now another vessel is born at the lower part of this same branch. And next time we went into this branch and dilated this also. So, so one of the advantages of this pulmonary circulation is is that we are able to, you know, get positive remodeling once the blood starts flowing into that segment. And, and you can see here that previously, there was no Venus return from this segment. And once we dilate and open up the flow into that segment, you will start seeing Venus return. And that is what we are aiming for is Venus return from that segment. And, and this is another patient with a total exclusion. You can see these branches totally excluded. And you know, you are, we're able to cross these, dilate them and all of a sudden now you have blood flowing into that whole segment. Uh Another total collusion you can see here, we dilate that it didn't look that great right, immediately after balloon Pulmy Andros we got here a month later for another uh session. And you can see how big this vessel has become and how nicely it has remodeled. Uh Another total exclusion. You can see there is no flow in this. Once we are able to cross it, dilate it, we were able to dilate both of these branches and now you have restoration of flow into that segment. Uh This is a, a very uh large lady with a BM I of 68 that surgeon said we can't operate on her and she had this interlobar artery occlusion and we were able to cross this inter lowbar artery occlusion and dilate it into each of these branches. And you can see the restoration of flow. Uh Here is another patient before balloon, pulmonary angioplasty. The perfusion after bone, pulmonary angioplasty, the perfusion on the right side and this is the left side and you can see they get significantly significant improvement in their perfusion. Now, here is another 53 year old female with a history of breast cancer. After chemotherapy, uh she had these significant perfusion defects. So she went for surgery and this was her uh PTE uh clot picture. And now this is her post uh PTE because she continued to have residual hypertension and was symptomatic. And you can see the perfusion is slightly better than what it was before PTE. But you know, when you look at selective angels, you see that there is significant distal webs uh in, in these, in these vessels. So we dilated these um and treated her with multiple balloon angioplasty. So pre pt her six minute walk distance was 109 and PV R was 7.6 with a mean P A of 40 and a cardiac index of 1.9 post PTE. Her six minute walk distance doubled to 2 24. Her PV R was 5.5 and A mean P A was 36 with an index of 2.17. So she got, she got better after PT but still was having significant residual ph and symptoms. So after balloon pulmonary angioplasty, you can see the right ventricle is still big. It's smaller than what it was, but it is still bigger and this is post balloon pulmonary angioplasty. Now, her six minute walk distance is 512 m. Her PV R is 2.65 mean P A is 31 and an index is 2.9. So you can see that there is a substantial incremental uh benefit of balloon pulmonary angioplasty in the patients who have already had PT and this is a Polish study that looked at post pt 18 post PT patients and showed that literally the results were same as those patients that didn't get PT. You can see the mean P A pressure dropped. Um The cardiac index got better PV R dropped and so did the biomarkers and six minute walk distance. Uh We, we do think that the improvement in pulmonary uh hemodynamics is slightly lesser in post PTE patients than in in non PTE patients. Now, what are the complications of balloon, pulmonary hydro blastic? You know, one of the things that we are most worried about in the cat lab is cough and pulmonary injury. Usually this is the biggest complication to date in pulmonary balloon angioplasty is is wire injury, cough and hemoptysis. Uh and the, the first thing you're gonna see is they're gonna cough. The moment a patient coughs assume that there is lung injury and they're bleeding into their lung and they get increased heart rate, their pulmonary pressures increase and they decrease their oxygen saturation. All of this happens very quickly and they negatively impact each other. And that there is a vicious cycle that is created. So this is our one patient that had a major hemoptysis. This is a post PTE patient that you can see there is some staining there. And the moment we use a two millimeter balloon to dilate this lesion and the moment we dilated it, she coughed and uh, and she was bringing her blood. So, the thing to do at that time is you have to maintain oxygenation and one way to do it is to isolate the two lungs. So the way we do it in the cat lab is we put a bronchial blocker. So the anesthesia team is always, they have kept all their equipment in the lab. They're always available on the phone that if a call comes from the lab that they have to be there right away and the person who knows how to use a bronchial blocker has to come down to the lab. Um So that's, that's one thing. So you don't want blood to come from one lung to other lungs. So you have to isolate the lungs, uh, sedate these patients and make them comfortable because they're scared and you reverse the heparin. And the most important thing you do in these patients is don't take that balloon out inflate the balloon proximal to where the injury is and keep it inflated for 10 to 15 minutes. You just literally sit in the lab, do nothing. Watch, uh, watch the patient, um, you know, feel better once the balloon is inflated and you have to literally keep the stock watch on and wait for 15 minutes. The other thing that uh we can do and we do is is injection of gel foam. So this is a surgery foam and you just cut it into tiny small pieces, mix it with uh saline and a little bit of contrast and create a small gel like this and then inject that gel through uh through a stop cock. This is, this is how you do it. And, and here is an example. There is a, there is a small uh extravasation from this wire here and you just give a gel foam uh and include the flow into that and this is how the vessel looked three months later, this is doctor Matsu Barra's patient, but they everything heals up. They, they just restore flow and, and they do really well. So the other options are like if somebody is bleeding too much and you're not able to stop the blood, you may need to use an alot or vascular plug, which is what we did in this patient. Uh You can do or if it is, if there is a pulmonary artery rupture uh in the proximal areas, then you may have to put a covered stent. Uh So, reperfusion pulmonary edema is, is a big deal. And, and we have had one patient uh that was repeatedly turned down by surgery, repeatedly turned down by us that had very proximal disease. And we dilated that proximal lesion uh with a five millimeter balloons was a 15 millimeter vessel and we dilated a five millimeter balloon and she basically did fine till the next day morning when she developed a white out of that lung on that side and needed an ECMO and unfortunately couldn't survive uh that hospitalization. Um uh So reperfusion pulmon edema in these patients is, is not a minor thing. So we just have to be careful about this. So the way to minimize or prevent reperfusion pulma is proper patient selection. You have to know which is the patient who is at highest risk and particularly if their PV R is high. Those are the patients you're going to get through perfusion pulp edema and you have to optimize those patients with medical therapy prior to balloon angioplasty. And the way we have been doing this and um and we learned this from, from Doctor Matsubara from Japan is, is undersized the balloons in the first round. So we just use dilate a lot of vessels with undersized balloons. And I also use pressure wire in those patients is I want to keep the distal pressure less than 35 millimeters mean. So hopefully that that's been shown to prevent uh reperfusion, pulmonary edema. Uh So if, if a patient does develop it, you have to give them oxygen, you have to monitor them closely. We dire all of our patients. We, we give them 20 or 40 of las six depending on the R A pressure. At the end of the case, we also use uh non-invasive positive pressure ventilation if we need to end and uh VA VV AMO. So, so this is not possible without a ac team. If, if it was just an interventionalist doing it, it would be a disaster. Uh This is usually um done with, with the CFF team. They are the ones who make a decision which patient should get a balloon, pulmonary angioplasty, which patient should not get it. And they are the ones who manage them before and manage them after. Uh So, because it's a treatment that is not, you know, we don't take out this clot like the surgeon does, we're just creating more pathway for the blood to flow. Uh So literally, it's a, it's a palliative treatment compared to, compared to a definitive pulmonary thromboendarterectomy. Uh So this is uh been our experience at at temple, you know, you can see uh the yellow bars yellow. Last year we did 90 pulmonary uh balloon angioplasty. And uh we have done little more than 350 pulmonary thrombo artoms during the same period. Uh and 23 of our patients have had post PTE and now we have done 244 BP A sessions in 92 patients. So we have done it in 92 patients. So far, 23 of them have had post PTE. So we have a fair number of patients who are post pulmonary trauma and arty. And 15% of our patients have not had uh elevated PV R uh in resting state. So, they were what's called C patients. And our hemoptysis rate is 4.6%. This is one of the lowest hemoptysis rates uh reported to date. Uh So we have submitted our, our manuscript. Uh This, this is our data. Uh you know, it hasn't been published yet. Uh But, but you can see the PV R decreased. Uh We, you can see the six minute walk distance increased by 70 m from 3 54 to 4 26. Uh The BNP levels dropped significantly, the pulmonary artery compliance improved significantly. And you can see this is an example of how the pressure looks uh across this lesion. This is the pressure here distally, this is ventricular pressure within the, within the transducer here, this is when you use a smaller balloon to inflate it, you convert a vege tracing into a pulsatile tracing. And when you use a bigger balloon, you basically normalize the pressure Uh So we have also started uh assessing these patients with quality of life questionnaire. And, and you can see this is an example of one of the patient who was class one, nyh, a class one, his baseline six minute walk distance was 531 m. He's a soccer player. And when he had a pe he had an intermediate risk pe uh and after the pe he wasn't able to play much soccer. So he, he was going, he also is a tracking person. He would climb mountains and, and he wasn't able to do as well as he used to do before he had pe so this was his baseline quality of life score of 29 which means higher the score, what the quality of life. And after four sessions of balloon pulmonary angioplasty, you know, his six minute walk distance increased by almost 90 m and he completely restored his, his exercise capacity, he's able to do everything he was doing before, after he had the balloon angioplasty. And you can see with every session, his uh quality of life score kept improving. And, and this is our nyh a class uh improvement. You can see our uh you know, uh classes have gotten better post balloon pulmonary andros. And you know, this is Dr Matsubara uh from Japan. He is in, this is my office and, and me, Yoshi and Bill and him uh were there and this is me in Japan with him uh for a week, they actually, they let me do, do a case there with them. This is, this is me. Uh So it was a very, very helpful experience. Um you know, they, they, they have the greatest amount of experience in bone, pulmonary angioplasty in the world. Most people have been trained by him. So uh if Annika is on Anika did a lot of work on, on, you know, our contribution to, to this space has been uh we have been doing venogram on literally everybody who comes to the cattle avid C and what we found is that 26% of them had what's called Me syndrome. And uh and this is probably the reason why these patients developed um uh developed DVT and PE in the first place. Uh So, so what, what we have basically been emphasizing uh uh in this space is, is think of pelvic vein obstruction and pelvic vein thrombosis uh in these patients because that may be the primary reason why they developed DVT in the first place and need it needs to be treated if it is causing any symptoms. Uh So what is the current state PTE is the first line therapy in CTF patients because it is potentially curative. Now, balloon palmy adios is a reasonable option in patients who have inoperable disease or are very poor surgical risk. So, but I, I want all of us to remember that that PTE is the first line therapy in these patients. Um but balloon Pulmy angioplasty is, is, is rapidly evolving and, and hopefully, um we will see um some U US data soon uh in, in print as to how uh United States is doing. Uh So uh that is it for the talk. Does anybody have any questions uh doctor here? Right. Yeah. Uh Is there any like concern for like like r stenosis after you uh to perform balloon? I know that the mechanism of obstruction is different in the pulmonary arteries. But do you ever, do you ever have to, I know you do repeated sessions, but do you ever have to treat the same lesions over again? And, and if there is r stenosis, uh how long does balloon, pulmonary plasty usually last before you get doses? Actually, the stenosis is much less of an issue in, in this pathology. You know, it, it's it what, what you are seeing is a scar and we're dilating the scar and, and what we do is um it actually remodels and gets better over time. But what I have also seen and, and that's what we learned from COVID is a lot of patients that we had treated with small balloons, but then they were not able to come back for bigger balloon dilations because of the COVID and they continued to progress their, their, their vessels, you know, dilated, distal to the lesions, their pressures increased. Uh they behaved just like as if they were never treated. Uh So I think it is very important to treat them with optimal balloon sizes before we stop saying that there is no risk stenosis. I think, uh now if you have treated them with optimal balloon sizes, the risk stenosis rates are very low. Uh But if you are using small balloons, the, you know, don't think that you have really treated them. They, they are still having the disease and they're going to still continue to progress. I, I, you know, I, I don't think we have a definite data on what is the incidence of these stenosis. At least we haven't seen in our data set. R stenosis doctor. I have a quick question. Do you think they're going to formalize like some type of certification process for BPAs or centers doing BPAs? So, uh for the first time, um a month ago, European Co uh uh European Society of Cardiology uh issued um issued a consensus document giving balloon Pulmonary angioplasty a class one indication. Uh So, so that's for the first time that balloon Pulmonary angioplasty is considered a viable therapy for patients with CTF. Now, that will bring in another issue is there are a lot of people who want to do this but uh you know, don't have systems in place. So what we have done is at a national level with Bill Ojea and Kenny Rosenfield, uh myself, Vikas and Rick uh Krasinski at uh at Duke, we have set up a balloon Angioplasty Alliance. Um And, and U CS D is part of that with uh with uh and uh we are working on a white paper these days. Uh So hopefully that white paper will have some guidance as to what should be criteria for people to start doing balloon pulmonary angioplasty. I can guarantee you the most important criteria for doing balloon pulmonary angioplasty is having AC F program that is accredited because if you don't have ac a program, you shouldn't be doing this, you have no idea what's going to happen to those patients. Awesome. Thanks, Doctor Bashir. Does anyone have any other questions? Yeah. So, II I also want you guys to, to understand that we have a very uh unusual and an incredible opportunity in, in improving the outcomes and care of these patients and, and I'm going to see if I can show you this, this case that I presented at TCT. Um Yeah, just to highlight what Temple has that others don't. Um So this is a, this is a case that I presented and, and this is a case of C TED. Uh So it's a 56 year old gentleman. I I showed you his quality of life questionnaire. He's a soccer player, hiker plays tennis, uh developed acute intermediate risk pe you can see on the CT scan. He is a, he travels a lot, you know, travels around the globe and in his, one of his travels, he developed this DVT and was complicated by pe, was treated by a Novak uh with anticoagulation alone, he recovered and went back to playing sports. But when he played sports, he noticed that he wasn't able to exercise as much as he used to. And he was even, he got a couple of times mild chest pain and near syncopy. Um And so the doctors um in, in his home state did a exercise stress test and which was normal, but he dropped his oxygen saturations at the peak exercise from 98 to 85%. And you can see his right ventricle is normal. So here is a normal right ventricle, uh no pulmonary hypertension, but he is limited in his exercise. So they did a VQ scan and you can see he has multiple perfusion defects on his VQ scan. And so because of these perfusion defects, they said let's make sure that what his hemodynamics are. So they did a right heart cat, his mean P A pressure was 23. His cardiac index was 2.1 and his PV R was 3.7. So really not significantly abnormal. And so they didn't know what to do. So they ordered AC T scan and you can see there are multiple distal perfusion, uh multiple distal webs including a, a pretty large bronchial collateral coming off the yo and um you know, 530 m was his. So basically by NYJ class, he's class one. So that highlights the limitation of this NYH A or double ho functional class because nobody does BPAs anywhere in the world on people with NYH A class one. So what do we do in them? So this is the kind of patient that you want to do exercise testing and because you need to be sure that if you are treating these patients, that you are actually having the correct diagnosis, because you know, treatment is not a minor thing in these patients. It's a pretty, you know, dangerous treatment, it can cause major complications. Uh So you can see you can have to c and there is this spectrum of, of problems that you can have in these patients. And the patients that benefit from exercise are ones who have mild or moderate C uh CT or C. Um So when you do invasive CPAT, that is the best test that gives you all the information and, and as you know, Paul does them with a metabolic card and the cat lab. Um uh and uh you know, you not only get rest hemodynamics, but you also get exercise hemodynamics and you get exercise capacity. And uh you know, you, you will be able to know whether the patient gave maximum exercise effort or not. And you also get gas exchange variables like VV CO2 and tidal co2. And this is the patient. His uh mean P A pressure was 22 at rest, it went to 57. His cardiac output increased from 3.8 to 11 index from 1.9 to 6 and his PV R stayed flat. So what this is showing is that he does not have any Parv uncoupling. So he, his RP A and RV are coupling well, because he's augmenting his cardiac output, he's augmenting his cardiac index. And you can see his stroke volume index increases from 32 to 50. So his Delta Co2 to V delta cardiac output to VO two is five. So he has no RV uh P A and coupling. But what he has is his VV CO2 is 42. That is high. That means there's a lot of dead space ventilation. And when you look at his uh oxygen saturation, it drops from 96 to 85%. And when you look at his P A saturations, it dropped from 67% to 16% at peak exercise. Now, if you look at his exercise capacity, it's 100 and 79 watts and his peak VO two is 26.5. So all the criteria that people around the globe are using, he doesn't fulfill any of those criteria to do any treatment of his CTA. But the fact is that he is limited in his exercise. He can't do what he was doing before. And, and these are his, these are his lesions. You can see he has multiple lesions everywhere in his, in his pulmonary arteries, there are tons of legions on the left side as well but no proximal disease. All segmental level level three disease. And we did four sessions on him from March to June of this year, 17 vessels, 33 legions and multiple of these legions required kissing balloons after these four sessions. His peer pressure now is mean of 12 and his PV R is 2.0 and his index is 1.8 uh six minute walk distance increased from 530 to 585. He could have done more but you know, in the hallway, you don't want to be running. Uh So his VV CO2, which is a marker of a dead space ventilation improved from 42 to 34. And now his oxygen saturation at peak exercise was 98% and I showed you how its quality of life uh scores got better with every session. So in these patients who have CTPTE improves quality of life and uh symptoms as well as in patients with CT. So, so clearly, uh patients with, with CT benefit from treatment of uh with either balloon angioplasty or with uh with PTE. So in, in these patients exercise CPT is a very helpful test in making an accurate diagnosis. And we at temple are very uniquely positioned because of what Paul and his team does. And with increasing B balloon, Pulmonary and uh angioplasty experience we are vascular more and more of these patients. In fact, hopefully, when our paper will get in print somewhere, uh it would include 15% of patients who have because most people haven't uh been using balloon, pulmonary angioplasty and CT, at least in the published studies. So that's, that's it. Uh Any questions anybody has any and you think they want to, to add two.