E116 Bill Kent on Minimally Invasive Techniques in Cardiac Surgery
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Chad Ball 00:12
Welcome to the Cold Steel podcast hosted by Ameer Farooq and myself, Chad Ball. We consider it an absolute privilege to bring you guests from around the world who are truly experts in their craft. Our mission is to offer you a combination of not only master classes on clinical surgery topics, but also insights into achieving personal growth, productivity, and fulfillment as both a surgeon, and perhaps more importantly, as a human.
Ameer Farooq 00:43
This week, we were joined by Dr. Bill Kent, a cardiac surgeon at the University of Calgary to talk about minimally invasive techniques (MIS) and cardiac surgery. We were curious to learn where MIS techniques fit in an era of rapid evolution in cardiac surgery, and particularly with the advent of new catheter-based valve replacement techniques. Dr. Kent had a number of important insights into the introduction of new technologies in surgery and the challenges associated with trying something new.
Bill Kent 01:26
You know, I grew up in Sarnia, Ontario, Canada. I grew up in a family with no doctors, so the fact that I've ended up here as a heart surgeon would have been an unlikely path, I think. My father was a judge, and I kind of felt that I would follow in his footsteps. And then as I learned more about it, I thought, not quite suited to follow that career path. So I actually did a undergraduate degree at the University of Western Ontario and I specialized initially in a liberal arts degree. I became interested in psychology actually, and I did a psychology undergrad degree. Through that I got interested in bio psychology and neuroscience. And through that path, I became interested in medicine, so I went into medical school after doing a master's in neuroscience; did my master's at the University Western Ontario and I did a medical degree at Queen's University. I did a general surgery residency, also at Queen's University. And at the end of my training in general surgery, I became interested in cardiac surgery. I think our career paths are often determined by our mentors, and I had a real good mentor at Queen's, who was a cardiac surgeon. And as I was finishing my general surgery training, he sort of said to me, I spent a lot of time with him, I thought I could learn a lot from this guy. And he sort of said, "Why aren't you doing cardiac surgery?" And I said, "No, I'm very happy in general surgery, I'm enjoying this, the career I'm going to have in it." And, and he sort of said, "Well, I really think you should do cardiac. So I said, "Well, I mean, I don't know, it's not sort of what I was planning on doing." He said, "You know, I'm going to look into some programs and see if there's just an option for you." And I said, "Well, sure. I mean, I might like entertain it slightly." He came back to me the next day and said, "I got you all lined up for a position in cardiac surgery in Edmonton. So you know, it's funny, you often fall into a career path that you didn't really previously determine. And this was a default sort of thing. So I ended up training in Edmonton in cardiac surgery. And that's where things started. Long-winded answer, but it was a circuitous path.
Chad Ball 03:56
You know, it's so funny how often we see that sort of circuitous voyage, as you describe it. And people who are real successful in life, whether it's in medicine, or elsewhere, I totally agree. I mean, our mentors really do guide us whether we have the consciousness to understand it at any given time or not. But that's really cool. You know, as you and I mentioned, or as I mentioned to you before the start of the podcast, most of our listeners - not all - but most are general surgeons throughout really an international audience and won't necessarily be up to speed on the latest advancements in cardiac surgery. I was wondering, with that in mind, then if you could frame some of the real recent advances that you guys have seen on the heart side of things, and I'm curious in particular, you know, we all know you locally, and I think across the country as doing some really neat work with minimally invasive valves. I'm curious how you sort of worked your way into that and how that came about as well.
Bill Kent 04:55
Yeah, well, you know, there's a direct line from my work as a general surgeon and learning about laparoscopic surgery that made minimally invasive valve surgery be an obvious fit for me when I became a cardiac surgeon. And I think a lot of those skills I learned in general surgery are very transferable to minimally invasive cardiac surgery. You know, as general surgeons, we sort of take that for granted. It's so much a part of our training using scope, doing lap choles [laparoscopic cholecystectomies]. I mean, these are things you learn as an R1. That's not the case in cardiac surgery training. This is all open surgery. So I had that skill set, and I felt that using scopes and understanding how to do that really had an application in minimally invasive valve surgery. It's an exciting time, I think, in cardiac surgery - in that field. I think that it's similar to 30 years ago in general surgery, when minimally invasive techniques were in their infancy. So I think we're maybe 10-15 years into it, in cardiac surgery, recognizing that smaller incisions and less trauma, less bleeding, earlier postoperative mobility, all that has a real impact on patient outcomes. So I'm very eager to take that field subspecialty - I should say - in cardiac surgery forward.
Ameer Farooq 06:33
Can you describe to us, Dr. Kent, what minimally invasive valve surgery really looks like, especially given our audience, as Dr. Ball says, is mostly noncardiac surgeons?
Bill Kent 06:42
Sure. So as we all know, most cardiac surgery is done through a sternotomy with an open approach. And sternotomy is a great approach for exposure. And still, over 90% of cardiac surgery is done that way, but there is there's real limitation postoperatively in terms of mobility. So patients after sternotomy can't use their arms for six weeks, they can't drive, there's pain-related issues with sternotomy; we use stainless steel wires to support the sternum to allow it to heal. But there is that process, just like if you do an open reduction internal fixation of a femur - the same thing with a sternum and it takes a while for that to heal. So, it really limits your mobility post-op and this is particularly true for patients requiring a walker or other issues like that. On top that, bone bleeds and so a lot of returns to the operating room are a result of sternal bleeding after cardiac surgery. And that could be anywhere [between] 2% and 5% of cases that need to go back to the operating room for bleeding related to the sternum. So the approach with minimally invasive is to make smaller incisions and go between the ribs. So the most common approach I would use would be a right fourth interspace mini-thoracotomy, a five-centimeter mini-thoracotomy and that gives me access with the lungs dropped on cardiopulmonary bypass, it gives me access to the pericardium through the right side and to the pericardium and then a really good access to mitral valve and aortic valve. So it's really applicable to valve surgery the most, not quite so much to coronary surgery, just you have to access all parts of the heart, but it can be done with coronary surgery, too, doing multiple mini-thoracotomies.
Chad Ball 08:44
So interesting. I'm curious, does the robot play any part in either local or international approaches? The reason I'm asking this that obviously I'm biased. When I was trained to use the robot in the US as an HPB fellow, we were doing robotic Whipples. But you know, the truth is honestly, that's a marketing scheme that we really don't engage in any sense in Canada at all. Is that similar in valve work or totally unrelated?
Bill Kent 09:15
I think it is, Chad. I think there's a parallel there. There's a lot of enthusiasm for using the robot, particularly in the US and not so much in Canada. I think that there are some limitations and I think they're similar. With scopes, we're able to do complex surgery through real small incisions and that the same general surgery. When you're working in the small incision, the robot doesn't give you that much more of an advantage. I think, you know, having a range of motion within the chest cavity might be an advantage, but on the other hand, you're losing that tactile sensation and the whole efficiency of the operation is not quite what it could it'd be, I think, at this point with robotics. I think robotics will come along and there will be a role. But right now, you're spending at least twice as long in the operating room to do an operation that with a thoracoscope, you could do much more efficiently at this stage. I feel that that's the general consensus at this stage.
Chad Ball 10:26
Yes. That's so interesting. It sounds exactly like our pancreatic head resection world for sure. How then does the MIS technology that your using interface with purely catheter- based approaches, whether it's in terms of indications or whether it's in terms of expertise?
Bill Kent 10:48
Yeah, you know, I think the catheter-based approaches is another reason that minimally invasive surgery has been blossoming lately and some of the technology that's used for transcatheter valve implantation. So, in simple terms, valves can be collapsed down and can be introduced through small sheaths, like nine or smaller French. And so that technology is also allowed us to collapse valves. So valves can be implanted through smaller incisions. So, it's sort of pushed the field forward. And it's also been a bit of a competition between surgeons and cardiologists, as surgeons start doing more valve work percutaneously, it's pushed us as surgeons to be better. It's been a good thing. So competition is always good, right, Chad?
Ameer Farooq 11:46
Competition is definitely good. So in terms of broad strokes, who qualifies for an MIS- type approach, when you're doing a valve repair? Are most people amenable to that type of approach? Or is it only certain specific indications?
Bill Kent 12:05
That's a good question, Ameer. I think early on, in my experience, I would choose patients and I would image them, I'd scan them with a CT, and I look for ones that were good candidates. And same in general surgery; you know the patients that are going to be more difficult - a larger or an obese patient, which is more of a technical challenge, you know, patients with comorbidities that are certainly more high risk. So, you don't tend to see those as the best candidates when you start your experience, but as you grow and your confidence grows ... and at this point over 95% of my mitral valve repairs are done MIS. And as your confidence grows with the procedure, you certainly [inaudible] a bigger patient population, you can benefit with that approach.
Ameer Farooq 13:09
So, I'm curious, is this something that you learned during training? Or is this something that you've picked up along the way?
Bill Kent 13:15
Yeah, as I said, a lot of these skills I learned in my general surgery - training transferable to cardiac - and then I did get extra training. I had the benefit of working here and being supported to travel to different places to learn techniques from surgeons that had mastered the technique. And then I had good support here in Calgary to develop the program as well. So, again, mentors and the ability to travel and see other surgeons operate. It's a process and it's a learning experience, of course, a lot of commitment, but certainly something that I was very keen to learn.
Ameer Farooq 13:54
You know, it's challenging sometimes when you're starting a new technique, especially when you have a well-established approach to doing this operation that is reasonably well validated and has reasonably good outcomes. I'm curious, and we talked about this a little bit already, but how did the outcomes compare between these two approaches? You mentioned, there's less bleeding, perhaps. What other kinds of benefits or not have you noticed from a minimally invasive approach?
Bill Kent 14:24
I'm glad you asked, because we're looking at that right now. It's true in all kinds of surgery, surgical research is a little tougher, because we aren't recruiting 1000s and 1000s of patients and giving them a placebo drug versus a study drug. So in surgery, you're going to have smaller numbers. A lot of the early research is based on cohorts, doing meta analyses, and trying to figure out the benefits is a challenge and particularly when you have a good standard of care. So for example, aortic valve replacement is a perioperative mortality of around 1% to 2%, and outcomes are great. It's a good operation. So it's some of the qualitative outcomes that you have to look at it in addition. So we've done some work here; we found that since we introduced the minimally invasive approach for the aortic valve, we're seeing less bleeding. So out of 100 patients, only four will require a blood transfusion. With a sternotomy it's about 33%. And that's our results from this centre; we'll see less atrial fibrillation, so about 20% atrial fibrillation or less than with a minimally invasive approach. And with sternotomy, you'll see 40% atrial fibrillation. In addition to that, it's quicker mobility, so no sternal precautions postoperatively. So they can use their walkers on day one; it's earlier discharged by about one to two days; and it's getting back to work, getting back to hiking the mountains. I had a patient recently who was a doctor who got back to his practice in 11 days after surgery. So this is stuff that we're not achieving with sternotomy. I think we'll learn more and more as we do more research on the benefits of this approach.
Ameer Farooq 16:25
What's your sense of the worldwide sort of adoption of MIS techniques, especially kind of, given the things that you've talked about it being very challenging sometimes to move the dial on introducing a new technique or a new way of doing things?
Bill Kent 16:40
Yeah. And there's always resistance, because my colleagues would tell me, "Why are you making it so difficult for yourself, you got a great operation with excellent results, like, why are you doing this, you're putting the pain on yourself?" But, you know, you see the benefit in the patients, you want to push the field forward, you want to do this, not only to advance the field, but to mainly help your patients and it's very rewarding when they - your patients sell you on, really; they tell you how quickly they've got back to work, back to doing things, back to activities and how minimal the pain was, and all that. And that really drives you. But until you start seeing those kinds of outcomes, it is a tough go at first. And I think that's why many surgeons are reluctant to and, you know, the data helps as more surgeons are convinced of the data and realize 'this is worth my while, and I got to put effort into this.' And the tide turns and more and more people are sold on doing it. But it's like anything else, when you start at first, you don't have all that many believers, but it grows.
Chad Ball 18:04
Yeah, it's interesting to reflect and talk about and think about the introduction of new technology or innovations in general. And you and one of your partners, of course, wrote a really neat editorial about the importance of patient-centred metrics and evaluating these techniques. I think that's sort of really what you're touching on. I'm curious how you guys, you and he, or you specifically approach partners in your group that perhaps would be a little bit more resistant to that change? And certainly it's not like - they're not going to retire in the next couple of years. How do you sell them? How do you have your patients sell them? How do you bring them into that fold and really show them benefit and convince them to jump on the boat with you?
Bill Kent 18:53
Yeah, that's true. I mean, you know, what do we all do, right? We all have our differences in our practices, and you got to respect your colleagues for their opinions and the way they do things. And as surgeons, we've got to have a comfort level with things. And so when I have a colleague say to me, "I don't believe really, in what you're doing in the sense that I want to do things, this is the way I'm comfortable in doing this operation; you can't convince me that I should do it your way." On one hand, I respect that, I mean, we all have our own comfort level, and however you want to get your patient safely through an operation is reasonable, but at the same time, it is good for us to challenge each other, and it's good for us to challenge our partners and say, "This is why I think this is better." The response I get from that is, "Yeah, well show me the data." It often comes down to that and it's on me and it's on all of us that want to innovate. You do have to do the studies. We're all evidence based, or at least we should be. So it does come down to that.
Chad Ball 20:10
It's so true that there is an art to convincing colleagues, both locally and nationally, even internationally to come along on that voyage. How was the actual technical side of getting approval to introduce a new technique and technology like this from a nuts and bolts point of view? Was it difficult or was it quite reasonable? How did the health care region that you're in view that and deal with it?
Bill Kent 20:46
In Canada, it is a challenge, and I think it's a good challenge; we're not introducing technology to make money for a hospital; we're introducing new technology; we're innovating for the betterment of the patients and patient outcomes. So that's a good measuring stick, and that's how we're measured. I've always found if we can demonstrate that this is going to be better for patients and it's not cost prohibitive (we do have to be cost conscious about some of these things), then it does become an argument that can be made. And I've found, of course, there were some battles early on in terms of, you know, you want that cross clamp that costs like 20 grand - for what - what's wrong with this one? But, for the most part, there is support, and if you're passionate about it and you can make a good argument that's based in good evidence and benefit of patient care, then I think you get supporters.
Ameer Farooq 22:00
I wanted to circle back a little bit to the difference between this approach versus a catheter-based approach? Do you think the big advantage still from a surgical approach to valve replacement is the longevity of the valves going forward? Or what do you think are the big advantages over let's say, a catheter-based approach to valve replacement?
Bill Kent 22:25
So, that's a massive advance for cardiology and cardiac surgery is percutaneous valve replacements, and it's not so applicable to many of the tricuspid valve, mitral valve; only the aortic valve is really amenable to it, and that's because it's got a more rigid annulus that you can balloon open a valve inside a stent. And it's saved a lot of patients the morbidity associated with surgery; but, the thing we don't know is long-term outcome. So is there a consequence of collapsing down a valve and crimping it up and putting it through the femoral artery? Is there a consequence of that? So, we don't have 20-year data like we do in surgical valves. So that's still to be determined. But, I gotta say, it's going to be at least 50% of aortic stenosis patients that are going to be managed with transcatheter approaches, particularly high-risk ones, and the technology is going to advance and it's probably going to be more and more and more. So it's a good thing for patients, certainly less invasive, less traumatic, much easier recovery.
Chad Ball 23:43
One of the last things that we wanted to ask you, which I think is quite topical, based on some of your comments, and in terms of the synergy between your general surgery training and really pushing the envelope and pushing hard with regard to innovation in cardiac surgery, is that link. What is your sense of direct-entry cardiac surgery programs, which, correct me if I'm off here, but it seems to be the standard for a while, at least in this country. What do you think the pros and the cons are of that?
Bill Kent 24:15
Real good question, Chad. I think that I'm a bit biased on this, as you might guess, because I trained fully as a general surgeon and I think there's a tremendous benefit to that. I think that in addition to learning the transferable skills in general surgery, it took me a while to learn if I was suited for a career in cardiac surgery and I think that a direct-entry program is maybe a more efficient way to do it. But there are a lot of medical students that go directly into cardiac surgery that realize they're not cut out for it. I guess I would say that there's more latitude to form a practice that's suited to you in general surgery; in cardiac surgery, you've got to have an academic practice, for sure, with the associated research and administrative demands, and it's busy; it can't be sort of an outpatient practice at all. And any operations are long, and so everybody's not suited to that. So I think it takes a bit to figure out if you're that kind of person. And in general surgery you've got a lot more options; you can do that sort of academic practice, like you do, Chad, with all those administrative and research responsibilities. But you can also have a community practice, and I don't think people know, in medical school, exactly what kind of practice they want to have. They learn that as they go through the residency training and so I think that's a downside. And there are a lot of direct-entry cardiac surgery residents who end up not finishing or transfer out and I think the proportion of that is higher. I don't have data for you in that, but I can tell you that's true.
Ameer Farooq 26:19
This has been an absolutely fascinating discussion. Once again, thank you, again, for joining us. One of the questions we ask everybody, almost everybody on the podcast is, if you could go back in time and give yourself advice as a trainee, what would that advice be having had the career that you've had thus far?
Bill Kent 26:35
Yeah, that's a good question. I think your career becomes really hard in residency. So there was a point at the end of my residency training into fellowship where I almost thought it wasn't worth it. And I think I'd almost go back and give myself a pep talk and say, "This is hard, but it is the most rewarding career that you can have." "And once you get out in practice and you gain confidence as a surgeon and you start to see the real rewards and the benefits that you do for patients." And you can't understand how rewarding that is as a resident and so when you get there, I gotta say, to me, it's been the most rewarding career I could ever hope to have. And so, even in those dark days of no sleep and slogging it away in residency, it really makes it all worthwhile. So, if I could go back and tell myself, "You know, it's okay, you know, you're gonna be fine and you're gonna enjoy this as much as I ended up enjoying it." It'd be helpful.
Ameer Farooq 28:01
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