Melanie cole, MS (Host): Welcome to UAB MedCast. I'm Melanie Cole and joining me today to highlight the robotic procedure, coronary artery bypass grafting, is Dr. Sasha Still. She's an Assistant Professor in the Division of Cardiothoracic Surgery at UAB Medicine. Dr. Still, thank you so much for joining us today. Before we get into the topic, can you tell us a little bit about your experience and interest in CABG and specifically MIDCAB?

Sasha Still, MD (Guest): Thanks for having me so I can talk about this special procedure. I'm an Assistant Professor at Cardiac Surgery here at UAB. I also, in addition to robotic CABGs, I perform a large breadth of cardiac surgical procedures from aortic surgery, complex valve surgery, but off pump coronary bypass grafting is near and dear to my heart.

And the impetus towards starting a robotic CABG program is really, it has to do with the fact that University of Alabama at Birmingham is one of the busiest, if not the busiest, beating heart coronary bypass program in the country. I mean, maybe even in the world. Training here and then practicing here has led me to acquire significant expertise in beating heart surgery, otherwise known as off pump CABG.

The vast majority of CABG procedures I perform are on a beating heart. I'd say 99 percent of them. I believe this method of surgical revascularization leads to less blood loss, shorter hospital stay, less transfusions. I think patients do exceptionally well, which compels me to continue and use this technique.

And furthermore, take it to the next level and start doing robotic assisted CABG or otherwise known as MIDCAB, which is also known as minimally invasive direct CABG. It gets confusing, but anytime we talk about robotic CABG, we'll be talking about a robotic assisted left internal mammary artery to left anterior descending artery bypass grafting.

Host: Thank you for that. So how does, as we look at the evolution of robotic technology. How has that impacted the traditional approach to CABG, and specifically, as you said, left internal mammary artery to left anterior descending artery and MIDCAB, tell us how that evolution has impacted and why you're so excited about this.

Sasha Still, MD (Guest): So, first, let's talk about some just basic fundamentals of coronary artery bypass grafting. Surgical revascularization via CABG treats coronary disease by bypassing a blockage in an artery that restores blood flow past the area of the blockage. This is done with either arteries or veins.

Specifically, one of the internal mammary arteries, sometimes a radial artery from the arm, or saphenous vein grafts from the leg. In the most, in the simplest sense, robotic assisted CABG allows a bypass to be performed through small incisions rather than a sternotomy. I robotically harvest the left internal mammary artery down the side of the chest, and then after that's completed, patient's heparinized, and through approximately a 4 centimeter incision in the front of the left chest, I perform the bypass on a beating heart.

This, compared to traditional CABG is, obviously much less invasive. Traditional CABG is via a sternotomy incision, which entails a large linear cut through the front of the chest, which requires also sawing open the sternum and closing it. Minimally invasive CABG, I go through the ribs.

MIDCAB, or robotic assisted LIMA to LAD bypass, it isn't necessarily impact traditional CABG. And what I mean by that is that it rather serves as a useful adjunct in the field of coronary surgery. So what we know is that a lot of people come in with complex multivessal disease and those patients should be treated with traditional bypass techniques through a standard sternotomy, because the studies have shown thus far is that in complex coronary disease, surgery fares better than PCI, meaning complete revascularization of all the vessels in the heart, it's been shown to have better outcomes. Now, similarly, less complex single vessel coronary artery disease can be better served with PCI rather than opening the chest just to, you know, hit one vessel.

Now, MIDCAB, or the robotic assisted CABG, bridges this gap, okay? Patients with coronary disease with intermediate complexity, also can achieve long term benefit from a surgical LIMA to LAD, in addition to well placed stents. This is called hybrid revascularization. So MIDCAB overall is not any type of replacement for a traditional CABG, but offers patients a long term benefit that wasn't previously offered by stenting the LAD alone.

Host: One of the interesting things, and you touched on it in your first answer, is the cutting edge aspect is that it's infrequently done in the United States due to its technical difficulty. How much, doctor, does the experience of the surgeon matter for this type of procedure? Training, experience, speak a little bit about that and the learning curves involved.

Sasha Still, MD (Guest): Without a doubt, this is a technically challenging procedure, and there are two complex aspects to MIDCAB. One is that the surgeon requires off pump CABG expertise, so you have to be used to sewing with very fine suture on a beating heart to perform, very important aspects of the most important aspects of the procedure, meaning the bypass grafting.

In addition to that, you need robotic experience. Now personally, I think a surgeon needs greater than 100 off pump CABGs under his or her belt to safely attempt MIDCAB. And the reason I say that is because you do not have the same exposure, and so you need to be facile with dealing with difficulties that may arise quickly, safely, expeditiously through a very small incision.

Strong fundamentals in off pump CABG allow for your increased patience, which of course is absolutely necessary anytime that you're going to pushing the forefront and trying new things for yourself, for your skills and your patients. So that increased patience is necessary to perform again, the most important part of the CABG procedure, which is the LIMA to LAD anastomosis.

Robotic training and practice is also important. Now, all types of surgeons in all different fields are learning the robot every day and that just gets used to sitting on the robot, understanding, how it functions, where the arms work, what patients to do it in, what patients not, and definitely my robotic training both as a general surgery resident and as a fellow allowed me the basics to move forward with robotic surgery as assistant professor.

Host: I'd like you to expand a little bit on patient factors and criteria. Describe the parameters, Dr. Still, that would indicate a patient would be a candidate. You mentioned single vessel versus multiple. Speak about why you would do this and who it may be contraindicated for.

Sasha Still, MD (Guest): So, surgical candidacy, let's do a little quick comparison. So, surgical candidacy for traditional CABG means that the benefits have to outweigh the risks for surgery, just like any other surgery. Generally speaking, the patient has to have reasonable functional status, graftable coronary disease, so would like to think and know that my graft is going to last a long time.

There's got to be an acceptable conduit, so good arteries, good veins, and the art of surgery, the art of medicine has to have a clear benefit of survival or quality of life, even in the setting of high risk surgery. Now, this is different for robotic assisted bypass. The criteria for me personally, and for I'm sure many others are, it's different and more stringent. And this is because of the specific technical factors that are necessary to perform the operation successfully, because it's more difficult. So one of these is, um, the appropriate body type and size for the robot.

So this is individualized. I make the decision actually after seeing the patient, putting my hands on him or her to understand where everything lies because sometimes the robot just will not function in certain people based on shoulder height, et cetera. Ideally, the patients are less than 110 kilograms.

Now, ever since I began doing robotic coronary, I've been increasing the weight limit over time because as we've continued to get more experience, we understand where the robot should be and how to be successful in individuals that are larger because of adipose or larger because of muscular structure.

Now, in addition to that, patients have to have a acceptable lung function. They have to require one lung ventilation, meaning I have to drop a lung to perform the surgery. If they're not going to, if their oxygenation is going to be bad, carbon dioxide starts trending up, I'm going to have to do it through a sternotomy.

Not having any prior heart or lung surgeries also is benefit. Now, because I'm, looking to have the most perfect cohort I can in terms of my robotic CABGs, I have not tried a redo or anyone with a, with prior lung surgery because of the adhesions in place. And that makes the surgery much more difficult.

In addition to that, I like it, I get a CTA chest on everyone beforehand so that I can assess the left internal mammary artery. This can also be done through a left heart cath. And then in terms of, based on their disease, who is an appropriate candidate, isolated proximal LAD disease is the best.

And I say that because, the longer the distal segment of LAD that I know that I can bypass, just allows me kind of comfort in the surgery, because if there is a mid LAD lesion, it means I'm going to have to go more distal, and so it just, a little bit more difficult in determining where to go on the heart.

In the setting of multi vessel coronary disease, we are performing hybrid coronary revascularization, meaning the patient will get a PCI and then three months to six months later a MIDCAB, or they get a MIDCAB up front and then we PCI later. That is a decision made in conjunction with the cardiologist that's taking care of the patient.

We want to ensure that all of our you know, hybrid revasc cases are very successful. And so this is like tailored decision making process through a heart team approach.

Host: This is such an interesting topic. Dr. Still, what role do interdisciplinary collaborations play for optimizing these outcomes for these patients undergoing robotic assisted MIDCAB?

Sasha Still, MD (Guest): Collaboration with other physicians is really central to appropriate patient selection. And that's what is going to allow this surgery to take on and to move forward, not just the state of Alabama, but also nationally and in the world because perfect outcomes, good outcomes, you know, I say acceptable, but my goal is always perfection, is what is going to allow us to continue to do this.

Host: Dr. Still l,ooking ahead, what potential developments or innovations do you foresee in the field of robotic assisted cardiac surgery? What excites you down the line? Give us a little blueprint for further research.

Sasha Still, MD (Guest): Robotic assisted cardiac surgery a hot topic. Here at UAB we perform a wide breadth of robotic mitral procedures, robotic tricuspid procedures, now robotic coronary bypass grafting. There really is constant innovation in terms of how to perform these surgeries better, how to expedite the patient's recovery process, even in the setting of minimally invasive surgery, which is also an expedited recovery process compared to traditional cardiac surgery through a standard sternotomy.

And additionally, there is now a somewhat of a push, at least I've seen, to try to figure out how to train people as they are training to be cardiac surgeons to perform minimally invasive operations. We're in a exciting, area of the field right now.

And I guess the next stop in terms of robotic assisted coronary bypass grafting is proceeding to a potential TCAB or a total endoscopic coronary artery bypass grafting program. It kind of depends on, you know, where you feel your niche is, because really even in the entire setting of minimally invasive cardiac surgery, there's really a place for everyone.

So, for now, for me personally, I want to do exceptionally well at robotic assisted LIMA to LAD and then after I find that the patients are doing well, have good long term outcomes, because in the short term they're doing fantastic, but in the long term they're still continuing to do fantastic, then I will consider branching out into additional robotic, maybe more bypass in a robotic CABG.

Host: Thank you so much, Dr. Still, for sharing your incredible expertise. It's really an exciting time in your field. Things are moving very quickly. And thank you for sharing the technicalities of this procedure with us. And for more information, please visit our website at uabmedicine.org/physician. That concludes this episode of UAB MedCast. I'm Melanie Cole. Thanks so much for joining us today.