An interview with Hiroo Takayama, MD, PhD, Chief of Adult Cardiac Surgery and Co-Director of the Aortic Center, Marfan Center.
Innovations in the Treatment of Aortic Disease
Heart surgery seems to be constantly revolutionizing itself with new technology and development. So, what’s new? What should we know about?
We really have five subspecialties: coronary disease, valve disease, aortic disease, heart failure, and the niche area. And there are exciting developments involving all four main areas.
Let’s start with your subspecialty, aortic disease.
Endovascular therapy is advancing more and more. Technological advancement is allowing us to do advanced endoscopic repair. For instance, previously, total endovascular repair and repair of aortic arch aneurysms could be only done with massive open operations. But we have identified both devices and groups of patients who benefit from endo[vascular], and that's very exciting.
As a team, we just discussed several patients who are not fit for open surgery, from things like being senile or having multiple comorbidities and complex anatomies. There weren’t really options for them before, now, those patients can be treated with endovascular arch repair.
We’re also expanding that endo approach to the proximal aorta, such as the ascending aorta or even the aortic root. Those are the utmost frontiers of endovascular repair of the aorta.
Explain how endovascular aortic repair works.
It starts with having a foundation of collaboration between cardiac and vascular surgery. V [Virendra Patel, MD, MPH, Chief of Vascular Surgery] and I see patients together and assess the anatomy together. The application of this endo arch technology has an anatomical requirement that is fairly strict. As you can imagine, it's also fairly technique-dependent. So, not only do we have to match a patient's anatomy with the device, but also advance the proficiency and collaboration among surgeons. We are advancing that field, and our division is hiring another aortic surgeon who is board-certified both in vascular and cardiac too.
That’s amazing. What about open surgical procedures for those who don’t meet the anatomical requirements?
We have established our excellence in aortic valve repair with an operation called the David procedure or valve-sparing aortic root replacement, where we can repair the aortic root without replacing the aortic valve. This has become routine at Columbia. We also collaborate with the congenital heart group and have a well-established team in the Ross operation, where a patient’s aortic valve is replaced with their own pulmonary valve. It is a very old operation, but recent super long-term outcomes data, we’re talking 20-30 years, shows incredibly promising results. Young, healthy patients are living long, long lives. We can offer the very best surgeons doing these procedures, as well as the aortic valve-sparing operation and other conventional procedures, like the Bentall procedure, where the aortic root and valve are replaced.
Are older procedures getting updated, or revived because very long-term data now exists?
If you are a good candidate, the David operation is the best procedure and will have the best long-term benefit. But just like an endo arch, you need certain anatomy.
For those with very advanced disease who need the entire valve replaced, the Bentall operation, where we replace the valve with a prosthesis, was previously pretty much the only option because the Ross operation had fallen out of favor. There were many issues, but now it's been revitalized. With specific attention to detail, it's become a good operation for people who are not candidates for the David procedure.
What has changed to create revitalization? Is new technology allowing for greater attention to detail?
Yes, absolutely. 3D reformatting of CT scans is how we’re able to evaluate anatomy and determine the best operation for each individual patient. We’re able to give our patients more choices and more hope. This change has only happened in the last three years.
Technological Impact on Valve Disease
Incredible. Let’s move on to valve disease.
What’s amazing here is that we’re offering robotic mitral valve surgery, and robotic surgery in general, led by the expert Dr. Arnar Geirsson. Robotics are an expanding frontier, and Dr. Geirsson is now doing robotic surgery for other types of heart disease, like tricuspid or aortic valve disease and congenital heart disease. There’s so much more to come.
What about transcatheter therapies for things like structural valve disease?
There are very, very interesting developments. First of all, we hired a great second surgeon, Luigi Pirelli, to help Isaac George and offer even more to patients. Transcatheter aortic valve replacement (TAVR) has become a standard in the management of aortic valve disease, and its role is being extended. Currently, it is only indicated for aortic stenosis, but now it's going into aortic regurgitation and other pathologies as well.
Additionally, transcatheter therapy is going into the mitral space, and we use a device called MitraClip to clip the mitral valve closed. This endo technology is now established enough that it’s being compared with open surgery. Three randomized trials are currently underway to compare the efficacy of a MitraClip versus open mitral valve repair.
When it came out, many of us were concerned about how it would pan out five or ten years after implantation. The data so far are looking very encouraging, so more clinicians believe in the technology. Patients want it because it's much less invasive and requires only a one-night stay in the hospital.
TAVR and MitraClip seem like very different applications of endoscopic technology.
Oh yes, there are fundamental differences. TAVR is reasonably similar to open surgical repair because both are replacements. Mitraclip is very different from mitral valve repair because mitral valve repair essentially restores the normal anatomy, whereas Mitraclip destroys the normal anatomy. It’s not a technology for young healthy patients who would benefit from having normal anatomy, it won’t be able to replace surgery. And with excellent valve restoration surgery that Arnar Giersson does, for example, it’s very difficult to ever reproduce those results with the transcatheter technology.
The Evolution of Heart Failure Treatment
How is the field of heart failure changing?
In the broad view, what's most impressive is the fact that the number of heart transplants in the US has significantly increased for a couple of reasons. One very sad reason is the fact that there are more deaths from drug overdose, making more healthy hearts available. But the other exciting reason is that we’re now using more organs from diseased donors.
So now we have two types of heart donors: DCD [donation after cardiac death] and DBD [donation after brain death]. Historically, donation after brain death was the only way because we didn't want the heart to be dead. But we can now use a chamber to bring the heart back to life really, really quickly as soon as we retrieve it. We basically put the heart in a machine and reanimate it as soon as the heart is removed from the donor. It’s pretty amazing.
How have hearts from diseased donors expanded the donor pool?
Previously, we thought the number of donors would remain stagnant. Meanwhile, medicine advanced. One example is the treatment of Hepatitis C. Hepatitis C was thought to be a progressive disease, ultimately leading to liver failure, but now new therapies are allowing for a cure. Obviously, that changes the scope of the donor pool. Currently, Hepatitis C donors are being accepted, provided recipients are aware of the history. So that has allowed us to do more life-saving transplants.
Do you see the availability of donor hearts expanding even further?
Yes, absolutely. It’s definitely opening a new field. One interesting niche area that’s expanding is the types of DCD donors. With donors from circulatory death, it’s becoming a more complicated question that has a more conservative and more aggressive application. The conservative way is that once the patient is off the ventilator and the heart stops beating, we quickly open the chest and retrieve the heart. The more aggressive approach, so to speak, is that once the patient is off the ventilator and the heart stops beating, they are placed on ECMO [a machine that temporarily takes over heart and lung function].
ECMO actually resumes circulation, and the heart will start beating again. So, you can resuscitate the heart in the body and then determine whether it can be used or not. Because ECMO can be placed very quickly and circulates the patient's own blood, there are many, many advantages.
Will this aggressive approach to DCD donation likely become used more widely?
As you can imagine, the aggressive approach has an ethical dilemma because you are restarting the circulation for somebody who is supposed to be dead. And before death, we know their brain was not completely dead because if it were, that would be a regular DBD. But through many, many ethical discussions, it’s slowly being adopted by many centers. We are about to start practicing this approach after a lot of continuous discussions with the ethics team. The conversation is actually going beyond transplant medicine now too. It’s a fascinating topic.
Cutting-Edge Approaches to Coronary Disease
What can you tell us about the treatment of coronary disease?
Two developments are particularly exciting: robotic minimally invasive hybrid revascularization and multi-arterial grafting.
With robotic minimally invasive hybrid revascularization, we are basically doing a bypass surgery through a small chest incision and stenting the rest of the coronary arteries.
With arterial grafting, the conventional way of doing coronary artery bypass surgery (CABG) is to do LIMA (left internal mammary artery) to LAD (left anterior descending artery), which improves blood flow. Patients usually need three or four bypasses for revascularization—one artery going to the LAD, and the rest are usually bypassed with a vein graft.
But our program has been doing this multi-arterial grafting for years. Dr. Craig Smith is the international expert on this topic, particularly using bilateral internal mammary arteries, and the world has finally caught up. Now, guidelines mention the importance of multi-arterial grafting. And that includes LIMA and at least one more arterial graft, like RIMA, or the radial artery from the forearm.
You mentioned the niche area of heart surgery earlier. Would you say that’s hybridized treatment, where surgery and interventional (catheter-based) approaches are combined?
Yes, championing existing open procedures with the introduction of minimally invasive robotic approaches, as well as hybridizing and exploring total endovascular or transcatheter options.
So, there are more options than ever before to repair a damaged heart, whether it's coronary artery disease, valve disease, aortic disease, or heart failure.
Our surgeons are at the forefront of incorporating all the therapeutic interventions. If it's a pure transcatheter or endovascular approach, both surgeons and non-surgical specialists like interventional cardiologists or vascular surgeons would be able to do it. But we are the only ones who can do them all.
Do you mean heart surgeons are incorporating endo or transcatheter therapies into surgery more and more?
Absolutely. In that sense, our division at Columbia is very aggressive in incorporating those cutting-edge technologies. We have two dedicated surgeons working with the interventional cardiologists on valve disease. And we're actually hiring another person who can do endo or transcatheter therapy on the aortic valve. We have developed many innovative procedures in that area.
What are you most excited about? What goals do you hope to achieve in the next 5 to ten years?
The fundamental part of our work remains the specialty of open surgical practice, which still accounts for 75 percent of what we do. So, we will continue our ongoing effort to improve outcomes in that huge domain. That will be the mission for the next five years or so.
At the same time, this currently smaller, even somewhat niche, fraction of the important work being done through either transcatheter or endovascular approaches should grow. I want to make sure our group stays at the forefront of advancing those therapies.
Related:
- Heart Disease Is Getting More Complex — But So Is Our Toolbox
- What the “Big Three” outcomes mean for you
- Why Robotics? Five Questions with Heart Surgeon Dr. Arnar Geirsson