In this Grand Rounds event presented by Penn Medicine, Matthew Williams, MD, Program Director of Cardiothoracic Surgery at Penn Presbyterian Medical Center of Penn Medicine, discusses the history and evolution of Coronary Artery Bypass. He elaborates on current techniques, patient options, and surgical updates.
Twitter @PennMDForum eso without 30 delay. Um, I'm gonna let Matt take this off, Bond, take us through and again. Matt is one of our senior surgeons here at Penn. Would a expertise in an interest in corner bypass grafting. And as many of you know, this feel has really evolved over the last 20 some years. And I'm looking forward to hearing from that. What the latest, uh, technology and the latest advance when we now see in coronary bypass grafting in our field. So, man, thank you. And I'm gonna mute myself at this point. Thank you very much. Great. Thanks, Wilson. Good morning, everyone. There's your CMI slide. So I'm going to talk about cabbage and new evidence around the issues of multi arterial grafting on a little bit about the minimally invasive cabbage today. You know, coronary bypass has in many ways been treated as a commodity operation. And you know, now new techniques on evidence is shed light on how cabbage can be better, and there is increasing evidence that it's really no longer a commodity operation. You know that the surgeon should be chosen very carefully to do coronary bypass. So if you look at a tally of all the surgery captured by the society. If they're asking surgeons in 2016 it shows the cabbage remains the most common operation Heart surgeons perform in America, and it's remarkable really how cabbage dwarfs all the other operations, like even if you were toe. But all of the valve surgery to gather cabbage still doubles those numbers. So it's really imperative to the field of cardiac surgery for us to do it well, because it's really most of what we do. Literally. Despite still being the most common cardiac cardiac operation, cabbage volume has really declined. If you look at the graph on the left there, cabbage volume in the U. S has fallen from 400,000 cases in 2000, down to about 200,000 cases a little bit more in 2010. And if you look at Pennsylvania, it's gone from almost 20,000 cases in 10,000 cases in 2016. Trend does seem to have leveled off in recent years, but it's obviously been a difficult period in heart surgery, though fortunately, pen has largely been spirit. That's been ah, coupled with major change in upheaval in many markets where large cabbage centers have declined due to the contraction of volume and are dominant procedure. So why are cabbage cases decreasing? Well, obviously, PC with new stent technology, improved restenosis rates has become more competitive. But, you know, the fact of the matter is that PC has declined markedly to so that's not the only reason. Um, there's a, uh, changes on medical therapy, particularly statins. Uh, the courage trial, though it compared medical therapy to PC I and stable angina might have had the effect of suppressing, uh, cabbage volume as well, because patients are less likely to undergo cardiac catheterization at all. Uh, patient preference is always a force working against cabbage. Patients don't wanna have there, chest quote unquote cracked open. And there's a lot fewer smokers, though you would think that would be counteracted by the increase in obesity and diabetes in America during that time period. But you know, the truth is, nobody is totally sure why Cabbage has contracted so much. And you've got to remember that that decreased utilization happened in the face of really pretty good data. And that time period cabbage was compared to PC I and multi vessel on left main disease on the syntax trial, the Freedom trial, the best trial, and I remember vividly being a resonant fretting about what the results of syntax we're going to be because it might determine the fate of cardiac surgery. But in truth, it turned out pretty good. You know, the the, uh, non inferiority thresholds really weren't met. And the truth is, cabbage remains a superior therapy for complex coronary disease. So what can we do to make this good surgery even better? Wanted to first look back at the evidence. That's the cornerstone of coronary bypass grafting the limit. Ella de graft. Uh, this is the manuscript published in 1986 Nikolay Clinic. Produce the graph on the right there. It's arguably one of the most important pieces of data in the history of cardiac surgery. The Y axis is survival. The X axis is years, and you can see that for patients with two vessel disease that involves the proximal led use of an internal memory graft increased survival by 10% 10 year follow up, and as a result of this data and other supporting data, the limit L. A. Has become the foundation of cabbage. So then that led to the idea that if one mammary is good, surely two would be better. And 15 years later, Dr Little and others also the Cleveland Clinic, reported the results of the use of bilateral memory grafting at their center and in a graph very similar to the previous one. Bilateral memory arteries is conduit showed around a 10% survival advantage of longer term follow up. So pretty good evidence for that second memory as well, and then following on that. That study lots and lots of observational data in publications that supported the use of the second memory. Uh, over the next decade and on. And this is a list of various bilateral memory artery grafting. Observational studies published this part of a meta analysis on The point is there were lots and lots of observational data that said bilateral I Emma's improve survival. But really, American cardiac surgery responded with a yawn. Its's very rarely used even now, less than 5% of cases in the last STS report and with no randomized controlled data, no strong demand from patients or cardiologists, it never really penetrated into the cardiac surgery zeitgeist and it remained a rarely performed operation. So some enterprising researchers, led by David Taggart, important cardiac surgeon in the U. K uh, this trial, the Arts Trial Very Important trial that was published. The 10 year follow was published last year. Around 3000 patients who are scheduled to undergo cabbage were randomized to receive either a single or a bilateral memory graph. The patients were then followed for 10 years, and it kind of was like, Want, want, you know, really? Uh, no detectable difference in survival and the front line analysis, and similarly, and the combined in point of death, myocardial infarction or stroke. There was no difference whatsoever. And really the curves air almost overlapping. So why did why did the, uh, the observational data show that it was so effective? And the this randomized data? Not so if we take a deeper dive into arts, there is a really large discrepancy between the intention to treat and as treated groups, 14%. That's one out of seven. The bilateral I'm a patients were converted to single I'm a so really large amount of crossover, and 1/5 of the single I am a group received the radial artery graft. Um, there are lots of founding treatments in the intention to treat analysis, and I think it's, ah, larger pitfall. It illustrates the larger pitfall for all surgical trials. You know, when a pill is the treatment group in a placebo is the control group. It's, ah, homogeneous. You know, it's all those pills in the treatment group are the same. That is definitely not the case and surgical drills. You know, the Wilson Zito is not the same surgeon as the people 300 miles away and in Ohio, it's ah, it's probably This problem is exacerbated, uh, technically demanding field like cardiac surgery. There's more heterogeneity in the treatment groups and you can see that in the conversion rate. Inside this trial, the conversion rate varied from 0% to 100% of going from bilateral. I am A to single I'm, and that just shows that there is a great deal of heterogeneity and and the treatment group. Another way is saying that cabbage, especially when using by a letter on Emma's, is not a commodity operation is not the same from surging to search. So if we look at the as treated group. Well, then suddenly the multiple arterial grafts look really good. Um, the patients who received multiple arterial grass enjoyed survival advantage of 10 years and for the combined endpoint of death and I are stroke, multiple arterial grafts looked much better a 10 years. So if we step back and think about why no difference in the intention to treat analysis, which is the front line presentation of the trial, it could be that there is genuinely no difference in treatments and that the as treated differences were all, uh, Sergio biases and assigning a second artery graph. Um, there are very high rates of optimal medical therapy in this drought. So something like 80% of all patients got exactly all the rate medications which might have blunted any effect of the of the second arterial graft. There was a high crossover raid, high use of radial arteries on, and you know, in my mind, I think that surgeon experiences is likely the critical factor. Not enough surgeons on the trail were facile with the use of the right imma how toe reach various grafting targets. Um, how to prepare the the conduit. And that was the fatal flaw of the trial. So let's test that hypothesis. They have done an analysis of the effect of surgeon experience. You look in the top part of this chart Mortality. Um, definitely favors bilateral. I'm a grafting at the surgeon were experienced. That is, if they did more than 50 operations inside the trial and for the composite outcome, it was quote unquote mawr significant, you know, shows, uh, more favorable, um, outcome for bilateral ramos and the hands of an experienced surgeon. That's a critical point to remember. And you know, to me, this is the most convincing graph for the benefit of bilateral IMAs that came out of the arts trial. This is the patient cohort of a single surgeon. So now you avoid the problem of heterogeneity in the treatment arm and you can see for this individual surgeon who had a crossover rate of only 1% so clearly this person knows how to use the right I m a. There was ah ah, quite a striking benefit for that second memory graft. And for me, it's convincing evidence that it is helpful when used correctly. So it's not all good news. With a second I am a graph. Even when the surgeon is experienced, there is the risk of deep sternal wound infection. Thea Arts trial did include patients who we would consider toe have risk factors for external wound infections. Even in the bilateral, I am a group. About a quarter of the patients had diabetes, 15% were smokers. And sure enough, 10% of the patients did have sternal wound problems. This could be a simple as some leakage of fluid from the wound or a full blown D external one infection. Only 1.2% of the whole cohort had the really serious kind of sternal wound infection that requires reconstruction flap reconstruction. Things like that, and that is a really serious complication. And in previous studies that's been shown, thio Thio be an attendant risk of bilateral. I am a use and the seriousness of that. That complication is illustrated by this statistic that shows that 12% of those patients were dead at one year. So it's even potentially a lethal combination Lethal complication Thio to suffer that deep sternal one infection. But you know, despite previous studies showing that I'm is gonna increased sternal wound risk external wound infection risk. Um, and it does appear that skeletonized harvest lessons that risk. So this is evidence from the arts trial that shows four different types of of I am a harvest P s I t a stands for pentacle, single internal mammary artery, internal thoracic artery esses skeletonized single on. But then you also have medical bilateral and skeletonized bilateral and the highest rate of sternal one complications were in the medical bilateral. But when the surgeon took the mammary arteries as skeletonized graphs that did seem toe reduce the risk of the sternal wound infection. So that's certainly what we're doing when we're doing bilateral internal mammary artery harvest. We still remain cautious, though, and you know people that are quite obese or have uncontrolled diabetes smoking COPD were wary abusing that second mammary graph. So let's talk a little bit about different conduit radial artery. This is, ah, conduit that's relatively easy and safe to harvest with experienced surgical help. It has superior Peyton see rates to the Stephanus vein grafts. It is technically straightforward to use. It's easier to use than the internal. The right internal mammary artery does have some drawbacks. It can't be used in moderate disease. It's not available in all patients on. We're working on quantifying how many of our patients are ruled out of radio artery due to their ultrasound studies and of good and bad. The radio catheterization is becoming more common. It seems to reduce complications of catheterization, but it takes half the radios out of circulation for us to use his condo. So unlike bilateral mammary artery, a za conduit, a Skonto a choice. There is high level data that supports the radial artery is a second conduit cabbage. This is published Two years ago, Dr Godino and Associates obtained patient level data from five previous randomized controlled trials comparing radial arteries to staff in this vein grafts. And they combined all that data and they were able to show that there was a market advantaged radio arteries clinically. So the rate of graft failure was much lower with the radial arteries and this combined trial combination of multiple Driulis, I should say the combined endpoint of death M I or repeat revascularization was much better with the radial artery. And if we break down those components of that combined endpoint revascularization, rates were lower in the radial artery group, myocardial infarction. Rates were lower, and the radial artery group death was not. But this the study did show a clear clinical advantage for the use of radio arteries over seven. This vein grafts, and to me, it was really the first really convincing evidence that the radio arteries were clearly superior. So I'm in this in this combination of Charles, which patients did better. There's some interesting details here. A Z you would expect if patients were younger. They enjoyed more benefit from the radial artery, so less than 75 years old did better with the radio artery. Uh, it appeared that female patients did better with the radio artery, and it's not really clear why that would be but an interesting finding. And then, um, the patients who had radial artery start to the circum. Flex systems seem to do better, too. So important little pearls toe help guide treatment selection for patients when using the radial artery. So now which one is better? The radial artery or the mammary artery? Well, the truth is, nobody really knows, and there's conflicting data. But there was a very interesting paper that, you know, I discovered and preparing for this talk. And it, uh, pointed toe issues that I think are largely explained by technical concerns for using the right internal mammary artery. Um, the study looked at short term outcomes only and compared patients in the STS database who either went radial artery is a second arterial conduit or the right internal mammary as a second arterial conduct. And it was kind of surprising if you look at the boxed results when you control for preoperative risk factors. It appears that radial artery patients are less likely to die as a short term complication of the, uh of the cabbage, which is really kind of surprising. And nobody would have expected the and pretty significant difference to an odds ratio of eight and then also were much more likely. Thio Radio artery patients were much less lately to suffer external wound infection. It is possible that it's all all these findings were due to the sternal wound infection, but I think more likely it's due to the technical demands of bilateral. I am a drafting and here's some evidence to support that, um, take a close look at these grass because they're not really bad intuitive, Um, for the y axis that's the risk of death or the risk of sternal wound infection in the second graph there. And if it's less than one, radial artery is better. And if it's greater than one, the bilateral I am A is better and on the X axis are different categories of patients. Excuse me. Different categories of surgeon It's on the X axis, its's 3% of total cases that air done using the second I am a graph. So for surgeons who are very low frequency bilateral, I am a users. Uh, not surprisingly, the radial artery patients do much better. But for the high volume Second, I am a surgeon's. There's clearly, um, you know, the this advantage the radial artery arteries have over the bilateral. I'm a goes away and in fact, it looks like the second I may is better in the hands of surgeons that are very comfortable with the technique. Eso again. I think it reinforces this idea that for particularly using that second mammary graft, it Z not really a commodity operation. There needs to be some experience and technical expertise. So, uh, to me, the the deal between comparing the two is that they're different patients who are going to benefit from different, different conduits. You shouldn't be in all one or all the other kind of surgeon. Uh, certainly for patients who have a high risk of media's tinnitus, Um, it's better to use the radial artery as opposed taking the second artery away from the sternum. Um, for patients with moderate stenosis residents severe the I am A is better. And obviously, if there's lack of owner compensation, that is, the owner artery can take over for the radio if you harvested or they've had instrumentation of that radial artery than Jaime is going to be a better choice for that second count. So, um, what does it look like in America right now? And what is the status quo for multi arterial grafting with all of this data coming out? So this is ah STS query of the patients who you would think surgeons would be most likely to put a second arterial graft in of any kind radial artery or the I M. A. Um, we took all patients who are less than 50 years old we're undergoing. I see cabbage, elective surgery so not even like an urgent or an emergency surgery. And they received two grants and any co morbidity is that might attenuate lifespan that might make a surgeon less likely. Toe the place is taken, arterial graft were excluded, and no patients who had any concomitant procedures either. So the most straightforward kind of isolated cabbage less than 50 no really significant comb our abilities. And if you look at the percentage of those patients who received a second arterial graft in America between 2000 and eight and 2018 that's hovering around 10%. You know, there's no trend that it's improving. And to me, this is surprising, truly, in a little bit disappointing data that cardiac surgeons air not using mawr multiple arterial grafts and this patient group who no would likely to benefit the most from it. And, you know, if you analyze this on the surgeon level, um, there were really just a small minority of surgeons who were doing any significant amount of multi arterial grafting, even in this group that would seem to benefit from it. So much so Onley. Around 10% of surgeons even put multiple multiple arterial grafts and 25% of the time. This group, Yeah, and only 1% of surgeons so very rare or even doing 50% or more of these patients using multi arterial grafts. So, um, you know, it's not much of a commodity as it's perceived to be doing cabbages. So I looked at our internal data to see how we were doing, uh, nearest of Pennsylvania Health System, and I brought in the category out a little bit. We didn't just look a less than 50 patients because that would be a pretty small cohort. We said, How many patients less than 75 who are receiving a second arterial graft. We didn't exclude for dialysis or significant liver disease or anything like that. Just a of, ah, quick and dirty study less than 75 years old. How many of them are receiving a second arterial graft? And you can see that we're doing a lot better. There is a steady improvement from 2017 to 2020 probably in the face of all this data. It's good that we've been responsive to it. Um, we we, um you know, have improved our grafting here. Presby from, you know, one and 6 to 1 and seven patients toe one and three for that group. And, you know, I think we can still do better. Uh, there are some areas that we could at a second arterial graft, and we're maybe we're not. No. One area of interest is how we're using the radio ultrasound toe rule patients out on whether it's, uh, largely size or owner compensation or what that's ruling patients out from that radial artery graft. And we'll be looking at that more closely over the next few months. So one group, historically a pen that has looks like we've undertreated Aziz patients with lower socioeconomic status. This is from a manuscript that was just accepted by J. T. C. B s that will. Patrick was the first author of one of our residents. And ah, we looked at all patients who underwent isolated cabbage at Presby and huh between 2005 and 2018 and we determined socioeconomic status simply by looking at their home address and correlating that U. S census data at the block level. That's a geographic area that's much smaller and more homogeneous than then, say a ZIP code, which has traditionally been used for these purposes. And the Y axis is the percentage of patients who have received a second arterial graft, and and the X axis is four different categories of patients. The far left is the lowest socioeconomic status, which seemed have the lowest used of multi arterial grafts. The far right is the highest socioeconomic status, and this was statistically significant and really kind of a convincing dose response curve. You know, as the patients, um, increase their socioeconomic status, they seem to be more likely to get a second arterial graft. So, uh, one possible area for improvement here, so in summary, with the multi criteria grafting, I think that surgeon experience that is a very strong relationship to successful bilateral man re crafting multi arterial grafting, whether radio or memory is beneficial and different patients will benefit from either the radio or the mammary grandma. So let's shift gears a little bit. Just talk quickly about minimally invasive cabbage and hybrid revascularization. There's all kind of different variations on this theme. Different operations that would fall under the umbrella of minimally invasive cabbage. But the dominant procedures the robotic limb harvest with a direct directly the lady through the economy, typically done in an off pump technique. That's what we do here. Presby. And you can see there's some promising published results for that technique. Uh, these air four different studies that described results for that procedure. They arrange in the number of patients from around 100 to 300 and the results were pretty good. You know, the mortality is low 0 to 1.3%. The conversion toe open surgery ranges anywhere from 0 to 9% in the Grasp Agency is pretty good. I wouldn't say it's perfect, but pretty good. So you know, this is a viable competitive procedure, and it looks like it has a reasonable learning curve. This is, uh, data from Dr Nirav Patel, whose uh, high volume robotic cardiac surgeon robotic cabbage surgeon in New York City. And he showed his first say 100 cases in this paper and show that after about 10 to 20 cases, the robotic Lima harvest, uh, efficiency really started to flatten out the improvements he was saying, and the time it took to took down the Lima and overall efficiency of the operation. It seemed to the learning curve seem to be 10 to 20 cases. Interestingly, that's what we found in our recent study. Looked at the learning curve for robotic Lima surgery on that guest database and that Z gonna be submitted STS We'll hear back if we got accepted here pretty soon. So that procedure lends itself toe high revascularization, which is ah, reasonable approach. The many thoracotomy replaces Lister mocks ternana me the limit l a d is performed drug eluting stents replace the seventies vein grafts. There was a major trial was funded by the that was going toe compare hybrid cabbage to conventional cabbage, but that closed due to a lack of enrollment. Another common problem and surgery research Because the magnitude of the intervention is such, the patients are less willing. Thio enroll. You know they don't wanna roll the dice to see if they get a not only invasive procedure maximally invasive procedure. So you know that Z gonna have a little bit of a chilling effect because no high level comparison is on the horizon. Um, it will still be an area of growth, the opportunity for growth for us. Another centers that commit themselves to it, but we won't know in the near term whether it's it's really as good as conventional cabbage. It's important to remember that this is a very small piece of the pie. UH, 2018 isn't pictured on this graph, Um, but from our study, we know that there were only about 1500 cases that were done in the entire United States in 2018. And if you look at the trend for the blue dots that's the robotic assistant cabbage. You can see that there's no trend that it's growing very quickly. It's been about 1% of the cases for 15 years, and the green dots down there, the hybrid cases and they're even less than the robotic cases. So you know, it's still a small piece of the Buy, and I think the technical demands her real barrier to entry for a lot of centers and surgeons. So we'll just finish with a recent case that we did here. This is a 48 year old man who was referred to me with increasing angina. He has Hyperloop anemia and, ah, strong family history. Yeah, the dad or he has a dad that had this old style cabbage, The Lima plus three veins when he was a young man back in 1988. Uh, parenthetically, the father told me that he does suffer with angina now, And, uh, under one. A recent calf that showed total inclusion of all of his native coronary arteries. All of his vein grass her down. And he has one Lima that's ah, powering all the blood to his heart. Not uncommon scenario. And patients that undergo cabbage. Uh, this patient one we're presenting today had a positive exercise stress test, so he underwent cardiac catheterization. These were just some still shots from that calf. The right coronary arteries picture that was interpreted as a 60% blockage. And that moderate coronary artery you can see on the left coronary shot. There's, ah, very tight, proximal led lesion that was interpreted as 95%. You can see there's kind of a bear area in the just little circum flex distribution. And if you cast your eyes back to the right coronary injection, you can see the rights left filling that included, uh, om two will call it, um, that's filling and looks to be a decent target. So he was referred for cabbage. And we decided in consultation with the referring cardiologists, the referring interventional lists that are drafting strategy. Yeah, limit led radial artery to that included om Be unlikely that a Rima that's still attached, Thio just wall would be able to reach to the distal sir complex circulation. We didn't want to put the radio to that right coronary and better if we didn't use the vein toe larger vessel like that. So we decided to use Reema to the ARCA. We thought we could get it To reach and not pictured was a a 70% diagonal lesion and a fairly large diagonal that we treated with the bank ground. So this is the some still shots of the conduit harvest. You can see this on the left. That's the Lima take down. That's a skeletonized lima. And on the right, you can see Deb Priorities Handiwork there, the very nice and the Scott pick harvest of, ah, radial artery, Minimally invasive approach. So let's see if the videos we're gonna work. Here we go. So first let me orient you the The white tubular structure is my dainty finger in the wound there on the far left. Um, over here. This is the aortic cannula. This is the right atrial cannula. This is a vein graft to the diagonal. And here I'm pinching on the side with my force up is, uh, radio ordering. We'll see if that will play a little bit. There we go. Get to hear Main talking Thio and pictured on the right There is the the flow of the vessel that showed very good possibility index and good flow through that vessel. This is the shot of the Lima. This is the skeletonized left internal mammary artery. And, uh, you can see there was really excellent flow to that. Hi. Great obstruction with a good hostility index is well, And then finally, here is the Rima to the R c. A. We were able to get the skeletonized graph to reach. And even though it was a 60% lesion, we had excellent flow characteristics, So it probably was the right thing to dio to graph up there, you can see the Remon. You're really only going to get that to read to that target using a skeletonized approach. It z no way it would stretch to that point with a medical harvest. So, in conclusion, multi material grafting is beneficial. Consistently successful use of the right internal mammary artery with a bilateral. I am a approach requires surgical experience and realize the benefit of that operation requires a little bit more advanced surgical expertise knowledge about taking skeletonized, um, conduit knowledge about where the Rima can reach and where it can I would add for a residence. You know, you shouldn't be, uh, completely averse Thio disconnecting the Rima from the chest wall, toe doom or distal targets that we didn't show any of that today. I think that that is a reasonable approach and you can attach the I am a to the aorta. And minimally invasive and hybrid approaches are our potential areas of growth. But it's important to realize where they are in the US right now. It's It's still a growing field. Thank you. That's it, Wilson, if you wanna open it up to questions. Thanks, Matt. That was fantastic. Um, um, there was a very, very nice summary of where we were, where we are, where we're going. Um, I would echo your sentiments. The perception that corner bypass grafting is a commodity. I would agree with you that if it was may needing a cabbage today, I certainly wouldn't viewed as a commodity operation. And I would go seek out the surgeon with the most experience in the latest techniques, for sure. So I would I would echo you 100%. I have a few questions, but I know there are also a couple of questions from the audience, so I'm gonna defer the audience questions first. And if I had there's time. I'll ask you some of my questions and thoughts. First question, then, um, Matt, maybe in comment on this, um, can you comment on the Peyton C of a free versus a skeleton Skeletonized. I am a especially the right. I am a Ah, right. Um, the true answer is that there is a positive of information about that. The scattered reports that are available. I have, uh, supported the position that there is no significant difference and the and the pendency of those vessels. But I think that the true answer is we don't really know, You know, there's not large Siris of medical versus, uh, I've seen enough medical, but you know what I'm in ASL attached to the chest wall compared to free. I'm a grass. I haven't seen anything from the arts trial reporting that I would be very interested to see that. I don't know. Have you seen anything about that, Wilson? What would be your I would ask you your thoughts. I mean, obviously, um, the conventional wisdom is that the pay agency, maybe, you know, there was a notion that the the pace insee right in the flow rates may be improved with a skeletonized memory artery. However, obviously that is not, um, you know, level a evidence at this point, but that certainly is a notion out there that has been perpetuated. Yeah, Second question, Um, is there any role for why grafting off the left internal memory artery? Yeah, sure. I mean, that's more of a style question, and I think they're special situations where it's probably beneficial, like the patient was a very heavily diseased A sending aorta that you know, there's increased danger and manipulation of that aorta. Certainly the no aortic touch operation could be accomplished of the Lima is used as the basis of inflow for other bypasses. My personal philosophy is that, uh, for patients undergoing cabbage, the true proven, most beneficial, Uh, thing that we do is the limit. L a d I try not to mess with it. I try not access it for inflow to other graphs. Um, and you know, that's gonna be the floor of my operation there. 100% going to get left internal mammary artery to L. A. Because just like my patient's father who was telling me his story, you know, he's ableto function, be alive, do everything he wants to do. He's got a little bit of angina, sure, but, um, you know, and his entire heart is perf used by the his lim l a. D. So you have ah, vessel with that kind of proof inability, proven benefit. I tried to not mess with a good thing on that one, you know. Yes, I would echo that. And I think just as a continuation of this question, um, I think they're certainly some scenarios were a sequential Lehman led to a diagonal Ornella de would also be a good option is Well oh, I think you're right. It's whatever the surgeon feels to his best technical ability to give the most durable and the most beneficial operation agree 100%. Question three Um, how now that the number of coroner ordered bypass grafting procedures have decreased? Mhm. Do you think our focus on improved health is contributory? I guess this is referring to better medical therapy, I guess, is the way I'm reading into the question. If I were Thio, pinpoint one most important factor for the contraction of cabbage. I actually don't think it's drug eluting stents. I think that's the convention with. I think it's probably statins. You know, statins have really altered the progression of coronary disease. And, you know, there had to have been some medical intervention that decreased both cabbage and PC I volume. And because that's what's been observed now, there are some recent reports that PC I volume is increasing maybe because of tavern and common procedures with Tavern. But, you know, the the medical therapy, I think, is the primary explanation. And I bet primary part of that is statin therapy. But that's just uneducated. Guess nobody knows for sure. Agree, Agree 100%. Um, next question. Um, is there any data for all arterial revascularization, e bilateral, internal memory and a radio in the same operation I get. Yes, this is as opposed to multiple or bilateral or two graphs or telegraphs. Is there any data on more than two are terra graphs. Uh, there have been some studies that have looked at this. There was a recent report from STS database that did not show any marginal benefit. Um, you know, it z going to be dimension original returns. But for me, when I have young patients like the one that was presented, I strive thio doas many arterial grafts as we possibly can because it is my belief that we can't detect it, you know, in this rigorous scientific way from observational studies that there probably is some marginal benefit to additional arterial grafts, particularly for, you know, optimal targets and things like that. Um, you know, So I think that was gonna be pretty hard to prove, but my gut is that they're probably remains some marginal benefit. I'd don't think the magnitude of that third arterial or the fourth arterial graft is going to be. The magnitude of that benefit is going to be as much as adding the second like waas the first you see what I'm saying? But e o another question. Um, can you comment on on pump versus off pump bypass surgery? Sure. So, uh, off pump surgery, uh, is less commonly performed than it Waas say, 10 years ago, I think the highest proportion of the operations in the US for about 25% when there was quite a bit of demand for it, you know, it had Really, um, you know, there are always two or three rooms that every cardiac surgical meeting, talking about off pump grafting. And, you know, in my opinion, the promise of off pump surgery was that it was gonna have better neurological outcomes and no, really be a less traumatic operation compared to on palm. And, you know, the data never really showed that it did show that there was less transfusion. And that was one rial benefit of avoiding the cardio need bypass machine. But then there were scattered reports that that the Peyton Sea of grass placed on off pump surgery were a little bit worse. Not terrible, but a little bit worse. And it was detected statistically. So you know it. For most patients, I think there's small benefits. Small potential benefits doing off pump surgery. And you know the strength of cabbage surgery is the durability of the bypasses. And so I think that, you know, my personal belief is that you want to construct perfect to bypass as you can. Now there's some surgeons that completely devote themselves toe off pump surgery and can achieve very good outcomes. And it's not wrong to dio. But for me, I reserve that technique for patients that have hostile aortas who have extremely marginal pulmonary function. I use it in a and, uh, in those particular sense. Great. Um, I have a question for you. Comment and a question. Matt, I think I think it's commendable that under your leadership that our bilateral or material or not, bilateral multi arterial graph percentage has gone up. I remember correctly is close to 35%. Is that right? In the less than 75 age group? Correct one or two more than one draft? Yes, So thank you for your leadership on. And I think that's important. Aziz, we try to continue to evolve or practice. Um, you also share some data that out there in the rest of the rest of our cohort that there is a reluctance to use multiple grabs. You went through all the reasons as to why, um, where do you think we should strive for? What is your vision of where that number should be? Have we peaked as 35% where we should be? Or do you think we could still be better? And what number would that be in your mind? Would be the ideal place that would end up It would end up in the next year or two. Yeah, that's a good question, Wilson. Um, probably a lot of different ways of looking at that problem. If you're just talking about all comers less than 75 not excluding, you know, significant vulnerabilities. I bet 50% is the plateau number for us. Um, I think that, you know, as we get more and more experience with the skeletonized memory technique, we could end up using parts of the mammary artery. Thio bypass other vessels. Um, you know that there's still some opportunities with the right internal memory artery. I bet that we're not using that at the highest level we could as a group. Um, yeah. So, uh, the other opportunity to me is looking critically at our radio ultrasound data, saying you know why patients are ruled out of using a radial artery? Are those valid reasons all the time can we expand and the a number of conduits that we deemed usable? But I think that there's still a place for bein grass, and, uh, it's not like they have no benefit. It's just, um no for the right patients, there is, ah, marginal increase Peyton C and clinical benefit to using this arterial grafts now in the follow up on that, um, as we continue to stri to doom or multi graphs or terra graphs. And as you mentioned, you went over the data very nicely and eloquently about. There is mounting evidence that that this is all good for patients. Is it time that we as a specialty work working with STS that perhaps a a second arterial grafts needs to be part of star rating for STS? Are we there yet? Just like we did make that leap with Lima as a star rating metric. Are we there yet? As a za another incentive to make surgeons move As you know we can be quite, um, creatures of habit. And there's like inertia. Is it time to put that additional incentive to move our specialty towards multi arterial grafts? Um, well, that's a tough question. You know, um, like, I'm I'm a proponent of doing the second artery graft. But then, um, there's so many people telling us what to do. I have I'm hesitant. Be the person who's wagging their finger and other surgeons and say, This is what you have to dio because it's a metric right. It's not You don't have to do. It's a metric and again doesn't have to be 100% like left internal mammary. But to put it out there, you know, Thio, get to three stars or keep your two stars. If you wanna look at it from that perspective, you got to start doing a better operation or you or you become a one star program. I mean, you know, this is all for quality and patient care, right? This is all about quality. Yeah, I would be. I would be supportive of it. I'll answer it this way. I would be supportive of it. If the goals were incremental and modest. It first you know, you don't want to try to compel surgeons to do things that are going to be harmful to patients. Maybe compels the wrong word. Incentivized surgeons, Thio do things. They're gonna be harmful to patients. As I showed in that radial artery toe, I am a comparison. It looked like the M a use of that. Second, I'm a among surgeons who do infinitely, isn't so great. And so there could be some knock on effects that actually, paradoxically, hurt patients. If we try to bring the hammer down too hard, you know, important to consider unintended consequences of any new policy. Agree? It's just something provocative on or throw out there because, I mean, you know, may I like to challenge the conventional wisdom dogma because oftentimes dogma isn't what we think it is. And that's how we move the needle on the field, right? That's problem. One more question from Jean, um, your personal thoughts on hybrid procedures. You talked about this using the robot limit led circulation or territory in a PC I somewhere else E no, the numbers, your small what do you see? The potential Zara's. I know you're starting to do that operation. What do you what do your personal thoughts of the potential in the future of that particular operation, I think, actually has quite a bit of potential. I think that maybe for the 45 year old person who you really want to get, you know, a ZMA any arterial grafts and as you can to give them the most durable treatment, it wouldn't be ideal. But for a lot of patients who are in their seventies, the vast majority of the benefit they're going to get from from cabbage is going to be the limit lede. And if you can achieve that in a way that minimizes morbidity for the patients, makes them more satisfied with their, uh, intervention. And, uh, I really doubt you lose that much with the modern drug eluting stent and non L A D targets in that particular context on the older patient. Um, you know, I think it's a very reasonable approach. Obviously, the the devil's in the details, and you have to get very good results to compare with the very high level of safety attached with conventional cabbage. But no, I think it's ah really area for growth that we should continue to push. Okay, I know our time is short. I see One more question. Um, can you comment about using radio artery as a conduit after a radio cath? Sure. Uh, I'm pretty uncomfortable with it that there is not a tremendous data showing one way or the other. But all of the conventional wisdom is that there can be damaged the vessel and that after instrumentation. Um, you know, it's it's not wise to use that vessel for at least three months, though. You know, I know it's beneficial for patients. Toe have a radial artery approach, but that is one knock on effect of radial artery catheterization is it takes about half the radios out of circulation. Wilson d o. Similar then dinner. I dio and I know this is a point of discussion with our interventional colleagues and please any, if any one of them ones on the line. Please join us and make some comments. I would share some of the same reservations using a conduit from the radio artery right after a cath. The question in my mind is, when is it okay after the count to use it? Fortunately, the majority of cast you done through radios on the right, Um, and most patients or right dominant. Which it means you're harvesting that left radio anyway, um, but occasionally, right. That that does come up. Um, um, I would share the same concerns in the last minute. That's left. Um um, any questions from the audience that air, like, may not technically savvy and probably can't type of chat question in or etcetera if they want to. Just ask the question, you know, food or audio. Any questions from the audience or comments that they wanna? I asked Dr Williams at this point. Okay. Um Well, Matt, thank you very, very much. We're right on time is 8. 30. That was very educational. Informative for me is why I hope it is the same for the audience. Um, And again, I want to thank everybody for joining us this morning. Um, with our cardiovascular surgeon, grand rounds, a pen and Presbyterian. Thank you, everyone. Everyone have a good day. They care. Take care.