Hear a Patient Power interview with Dr. Jeffery Meadows, pediatric cardiologist at UCSF Benioff Children's Hospital, and director of the Pediatric and Congenital Cardiopulmonary Exercise Laboratory.
Hello and welcome to Patient Power sponsored by UCSF Medical Center. I'm Andrew Schorr.
There are some children, fortunately not many, who are born with some heart valve problems, congenital heart problems, and these can weigh down on their quality of life over the years. And sometimes, even as they develop into adults the problem can get more severe, but certainly it's a concern. And it can cause big problems in some people down the road, even death, certainly an enlarged heart, but could lead to arrhythmias as well. So you want to recognize it, and you want to treat it.
Now, does that mean you need open heart surgery? Traditionally, that might be an approach, but what if you could go in with a catheter and fix that leaky valve or problem valve in the heart? We're going to talk with an expert now, Dr. Jeffery Meadows. He is an interventional pediatric cardiologist at UCSF Medical Center. He's director of the Congenital Exercise Physiology Lab there, too. Dr. Meadows, thank you for being with us on Patient Power.
It's a pleasure to be here.
Dr. Meadows, so first of all, what are we talking about? What's the valve that can be a problem that a child might be born with that's just not doing the job?
There are four valves in the heart, and two of them are within the heart and two of them that lead out of the heart. And the one that this Melody valve is made to help replace is the pulmonary valve, which is the valve that usually leads from the right hand side of the heart out to the lungs.
OK. So this is where the heart is pumping blood through a valve to the heart to be oxygenated so we have energy, right? And it fuels the body.
Yeah, indeed. If you look back to your days of general anatomy in high school and stuff, the heart has two sides and four chambers. The right hand side of the heart takes the blood that's been used by the body and needs to get more oxygen, and it pumps it out to the lungs, and the lungs give the blood oxygen, turn it bright red, and brings it back to the left hand side of the heart that brings it out to the body to be used.
It's the pulmonary valve, which is the valve on the right hand side of the heart leading to the lungs, that we're able to replace now in the Cardiac Catheterization Lab.
OK. And you mention this Melody valve, and I had sort of alluded to the fact that there had been big changes. So I said that traditionally somebody might ultimately need open heart surgery. What are you doing with catheters and this Melody valve now?
The Melody valve was initially designed to be used in patients who have already had surgery, so specifically in patients who either had no pulmonary valve to begin with, or a pulmonary valve that was simply too small to be adequate for them. The surgeons would go in, open the chest, put the patient on bypass, and they would sometimes insert something called a homograft, which is a cadaveric aorta or pulmonary artery, and they would sew that into place on the right ventricle and to the pulmonary arteries, and that would provide a means for unimpeded blood flow to the lungs.
Now, those would have valves in them, but ultimately the valves would usually fail. They would either become narrowed, or stenotic, or they would start to leak. And so that's the patient population that this Melody valve was originally designed for, was these circumferential tubes that were placed by a surgeon of known diameter that we could put this valve in.
And perhaps at this point it might be useful to describe what the valve actually is.
What it is, is a bovine, so a cow, jugular valve. So it's a valve from a vein in the cow's neck that's actually quite large, and it's sewn into a stent, which is a metal mesh structure, kind of like a mesh metal tube that can be crimped onto a balloon. And what you do is you bring the balloon and this stented valve up into the area that you want to place it, you blow up the balloon and that expands the stent and brings it in opposition to the homograft wall or the pulmonary artery wall. And you take the balloon down, and the stent stays there by its full expansion, and the valve starts to work immediately.
Wow. All right. So versus open surgery, do you stay in the hospital as long? Is there less risk? What are the benefits to the patient by having this valve put in by a catheter?
The benefits are really quite substantial. You know, the historical alternative to this is to have the surgeon go back in, open up the chest, put the patient on bypass, either remove or cut open the existing homografts that they put in there, and then lay a new one in there or put in a different type of pulmonary valve. Then they sew it back up, and then the patient has to recover for a week or so with lots of pain and the usual kind of postoperative stuff.
The Melody valve procedure is done without surgery. It's done through cardiac catheterization, which is usually done through two small holes down in the leg. And the whole procedure takes about, if it's uncomplicated and you don't need to do anything else, about two or three hours, and it can be done either with general anesthesia or even just somebody comfortably sleeping with some light sedation. And it's relatively painless. It doesn't require opening the chest or being placed on cardiopulmonary bypass. The valve works immediately, and the patient can go home the next day.
Versus how long might they be in the hospital if they had open surgery?
The usual stay for an uncomplicated pulmonary valve placement in an older child or an adult is usually around five to seven days.
Wow. Versus going home maybe the same day or the next day.
Wow. OK. So is your experience that this has been as effective?
My experience with the Melody valve comes from two geographic areas. The Melody valve was first designed and utilized in the U.K. A doctor by the name of Philipp Bonhoeffer was the first to do this. He literally just sewed a valve into a stent he already had and started testing it, not in patients obviously, and then refined it. And so the Melody valve has been in use in the U.K. for much longer than it has in the U.S., as is often the case.
And so the evidence for the effectiveness and the long term efficacy of the Melody valve comes from the U.K., although trials had to be done in the United States to validate that. And it really is a very impressive system. And like most things in congenital heart disease, it's an evolving technology.
In terms of valve function, a valve can do one of three things. It can work perfectly, or it can leak, which means that it doesn't prevent the blood from going backwards, or it can become narrow, which means it makes it difficult for the heart to pump the blood out through it. And the Melody valves, once they go in, almost uniformly work beautifully immediately. And then over time their resistance to leakage is actually quite impressive. So the long term follow up that's coming out of the U.K. right now suggests that the Melody valves have very little leakage up to 70 months out, so several years out obviously.
The one issue that has come up with the Melody valve has been that some of them will get obstructed so there will be narrowing through the stented valve. And there seems to be a number of reasons why that happens. In the early generation of the Melody valve, which are no longer being implanted either in the U.K. or here, there were just some design issues related to how the valve was sewn in there that led to some of them getting narrowed. Since then the design and the manufacture of them has changed and they have less of that.
But still the dominant problem of the Melody valves seems to be that every once in a while the stent that the valve is sewn into will break. And it doesn't usually cause any acute issues, but it can cause the valve to get narrowed or the area that the valve occupies to get narrowed. And in that case one of the most efficacious things to do is simply just put in another stent.
Hmm. Dr. Meadows, so originally, as you said, this was approved for children and adults with congenital problems where they had already had open surgery.
But with your experience at UCSF, are you finding a broader use for it?
We are, we and many other centers in the United States. As you may or may not know, once the Food and Drug Administration approves a medical device, or a drug for that matter, for use by physicians, then it's available to use as physicians see fit. The indication for the Melody valve that was approved under the FDA was for very specific patient populations who had previously had surgery and had a tube placed from the right ventricle or pulmonary artery of a certain size.
But it clearly has found use outside of that. So in patients who haven't had that tube placed but just have narrowed pulmonary valves or pulmonary valves that leak, it's been implanted in what we call native right ventricular outflow tract, so people who have not had surgery but may have had a balloon procedure or may just have an abnormal pulmonary valve to begin with.
And you're having good results there, too?
We are. So far it seems to work reasonably well. The approach to Melody valve implantation, in part because of the original concerns about the stents breaking, very frequently we will place one or two or more stents without valves into the area that the valve will go into to help provide additional strength to the stented valve. And so people are doing that both here and elsewhere in the country, and these native outflow tracts as well, implanting bare metal stents that don't have valves, one or two of them, to help give added strength to the area, and then go ahead and planting the stented pulmonary valve within those stents, so you can end up with two or three stents and then a valve inside of that. And it ends up to being a very rigid, robust mechanism for supporting the pulmonary valve in the long run.
Dr. Meadows, just put this into perspective for us lay people. Is this a big deal?
It's a huge deal. It's really one of the first major advances in structural interventions and certainly valve interventions in the last 20 years. You know, some of the earliest interventional cardiac procedures performed for people with structural disease were opening narrowed valves, and it's a relatively crude mechanism but quite effective. You simply take a balloon, you advance it across the area of the narrowed valve and you blow the balloon up, and you just open up the valve with the balloon. And that was one of the very first structural interventions ever done.
But it's been well over 20 years since anybody has been able to deal with the leaky valve, and that's just been an issue of technology and the ability to do things at a scale that would actually work through a catheter. So it's revolutionized the treatment of valvular disease on the right hand side of the heart.
All right. So then you say, well, what difference does it make to an individual? So I know you have a lot of kids and adults come through there, and maybe the problem was known since birth, maybe it was noted by their pediatrician or somebody as they were growing older that there was this valve problem. So they think maybe they're doing OK, but somebody said, well, we've noticed this problem. So tell us about the difference you've seen it make in some of your patients.
You know, the difference can be quite dramatic, and sometimes, at least to the patient and their parents, unpredictable. And I think part of the reason for that is that when you're born with either a simple valve disease or more significant structural heart disease, you probably had a limited ability to exercise and exert yourself from the start.
Maybe you didn't know it.
Yeah. It's very hard for people who haven't experienced something to know what it's like until they've experienced it. This is the same for what it's like to have a child as it is for what it's like to taste chocolate for the first time. If you've never experienced it you don't know what it's like. And so children born with structural heart disease who had never experienced a normal ability to exert themselves don't know what it's like, and so often they will think that they're just fine because they've always felt this way, or because the change in their exertional capacity has been so slow that they just haven't noticed it.
And so it's not uncommon at all for children and for their parents to think that everything is just fine — this is the way my son or daughter has always been, and they're not limited. But then when you provide an important intervention such as the Melody valve or something else, the parents will come back and see you in clinic and say, 'Oh my god, I had no idea. I've never seen my child this active. They run better, they breathe easier.' I mean, it's a very impressive change.
And also you know that down the road, because of the body trying to compensate for the valve problem, they may be then heading off more severe problems in the future, right?
Indeed. And this is one of the things that's changing as a result of the Melody valve placement is that, no valve that we put in right now, either surgically or in the catheterization lab, will last forever. And so whenever we have to think about when to put the valve in, we have to weigh the risks of putting the valve in with the potential benefits.
And so historically we've waited a fair amount of time even though we know the dysfunctional valve is having a bad effect on the heart. We let it go on for a little while because we don't want to do seven surgeries, we want to do six surgeries over the course of somebody's life. And so that risk/benefit analysis happens every time you think about a medical intervention, because you don't want to take somebody with a trivial valve problem and subject them to the risks of surgery or another procedure if you don't need to, or if you can delay it a little longer.
Well, now that the risks of replacing a pulmonary valve have changed — because you don't need to open the chest and you don't need to go on bypass and you don't need to be in the hospital for a week, but rather you simply need to be asleep for a couple hours while we put it in — the risk analysis changes. Because the benefit is the same but the risk has decreased. And so we find ourselves actually implanting pulmonary valves in the cath lab a little bit sooner than we otherwise would send somebody to surgery.
Well, it sure seems like a real quantum leap in your ability to repair valves, and, as you said, give people a brighter future and perhaps have fewer interventions. So I guess in your field of pediatric interventional cardiology, as you said, this is a big deal.
It's really a revolutionary change in the way we manage patients because it allows us to do a procedure that was formerly surgical as an outpatient type of procedure. And then at least in our minds, avoiding surgery is a really big deal because there are risks to the surgery itself, but in addition to that every time the surgeon has to go into the chest to do a different operation it gets harder and harder every time, because of adhesions and scar tissue that forms within the chest.
So the first time a surgeon goes into somebody's chest to do a surgery for congenital heart disease everything is pristine, and everything is as it was originally made. The next time he goes in there he sees a lot of scar tissue, and he sees a lot of fibrosis and other stuff, and it's very difficult. And there's a lot of bleeding just trying to find the heart. So if you get somebody who has had more than a couple surgeries the surgeons get really apprehensive about going in there because it's just so difficult to find what they're looking for.
Well, I am glad that we can eliminate some surgeries as you have a device like this that you can put in through a catheter. Thank you for explaining it to us, and I know it's very helpful for parents and as people maybe have been living with this for a while, maybe they're now an adult, to understand what the options are at a center such as yours, UCSF. Dr. Jeffrey Meadows, thank you so much for being with us, and thanks for all you do for people with these valve problems.
Thank you. It's a privilege to be able to help folks.
All right. Andrew Schorr here. Thank you so much for joining us, and as we like to say, remember, knowledge can be the best medicine of all.
Recorded October 2012
Reviewed by health care specialists at UCSF Benioff Children's Hospital.
This information is for educational purposes only and is not intended to replace the advice of your doctor or health care provider. We encourage you to discuss with your doctor any questions or concerns you may have.
Pediatric and Congenital Cardiopulmonary Exercise Laboratory
505 Parnassus Ave., Suite M-344
San Francisco, CA 94143
Phone: (415) 353-1931
Fax: (415) 353-8675
Interventional Cardiology Program
505 Parnassus Ave.
San Francisco, CA 94143
Phone: (415) 353-4704
Fax: (415) 353-4144