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Conan Gasque (Host): Welcome to Inside Pediatrics, the Podcast brought to you by Children's Hospital of Alabama in Birmingham. I'm Conan Gasque. February is American Heart Month and Children's of Alabama has one of the largest pediatric cardiovascular programs in the Southeast. Last summer we became the first hospital in a 10 state region of the Southeast to perform a procedure with a device that's intended to reduce the need for open heart surgery.

Joining us now is one of the doctors to perform that procedure, Dr. William McMahon. Dr. McMahon, thanks so much for your time today.

William McMahon, MD (Guest): I'm happy to be here. Thank you.

Host: So, first of all, let's talk a little bit about your role here at Children's of Alabama. You're an Interventional Cardiologist and you really have a focus of less invasive procedures. That's something that's a really big deal to you. Can you, can you kind of explain what that means?

Dr. McMahon: Yes. Some of my patients think I'm a surgeon, but what we do, what I do and what we do is, is minimally invasive catheter based procedures. I commonly say to my fam, my patients' families, similar to an adult, having an angiogram where we can frequently take care of heart defects, treat heart defects that in the past needed open chest or open heart surgery for repair that can now be treated or repaired with a transcatheter approach just going through the vein in the leg, rather than opening up the chest and opening the heart.

Host: And that is why we're talking to you today because you perform this particular procedure with the Harmony Transcatheter Pulmonary Valve. We'll talk a little bit more about that, that device in a minute, but first to kind of set things up here, we need to talk a little bit about the condition that this procedure is for, Tetrology of Fallot. For people not familiar with that, what exactly is it?

Dr. McMahon: So, to Tetrology of Fallot or we commonly call it Tetrology for short is one of the many birth defects of the heart. Like all congenital heart defects, it occurs when a baby's heart doesn't form correctly as the baby is developing in the first few weeks of pregnancy. Congenital heart defects of all types are really very common. Congenital heart defects affect a little less than 1% of all babies born in the United States. And that amounts to about 40,000 babies per year in the United States. Babies affected with Tetrology in particular, amount to about 1 in 2500 babies. So, between 1600 and 2000 babies per year. It's called Tetrology because the initial reports of this heart defect described four abnormalities that were commonly found together in affected children.

But for practical purposes, there's really two major abnormalities. One is a large hole in the wall between the two pumping chambers called a ventricular septal defect. And the second abnormality is stenosis or narrowing of the pathway from the right ventricle of the heart, to the pulmonary arteries. And this is called pulmonary stenosis. The severity of the pulmonary stenosis varies from baby to baby. And it's an important determinant of the overall severity of the baby's condition. Like most heart defects, the ultimate treatment is surgical repair of the defect. Most babies with Tetrology will have an operation at three to six months of age to repair the pulmonary stenosis and close the VSD.

Following that, most babies with Tetrology will go on to live active and healthy lives, during childhood, after they recover from the surgery. They do need regular checkups and visits with a pediatric cardiologist to look for potential problems. As older teens and young adults, persons with repaired Tetrology may need more surgery. The reason for that is that the most common surgical method to repair the pulmonary stenosis is for the surgeon to use a patch to enlarge the narrow area. This very commonly results in leakage of the pulmonary valve. The leakage is usually very well tolerated for a long time during childhood, but with time, heart enlargement occurs as a result of the leakage of the valve.

And at that time, cardiac symptoms are more likely to occur and there may be concerns about heart failure. When this occurs, most patients will be referred to have the defective pulmonary valve replaced. The most common age for children and young adults with Tetrology to have surgery to replace the pulmonary valve is the late teenage to young adult years. Traditionally, the pulmonary valve replacement requires another open heart surgery. The surgeon opens the chest. Places the patient on cardiopulmonary bypass. The cardiopulmonary bypass is a pump device that takes blood from the patient, oxygenates it and sends it back to the patient to support the blood flow and the blood pressure.

This allows the surgeon to stop the heart, open the heart, in the case of pulmonary valve replacement, they will open the area of the right ventricle and the pulmonary artery, and sew in a new valve. Once that's done, they close up that area, restart the heart, take the patient off of pulmonary, cardiopulmonary bypass.

Host: So I, it's obviously a very invasive surgery, when you talk about open heart surgery. Can you talk a little bit about the impact that, that can have on a patient in terms of what they experience in the aftermath of that surgery?

Dr. McMahon: Well, as common and safe as it has become, we can never really forget or minimize the fact that the midline sternotomy, the incision in the middle of the chest, the cardiopulmonary bypass and the conduct of an open-heart surgery on a person is among the most invasive and traumatic of treatments that are undertaken on a routine basis at a children's hospital.

It's a huge undertaking and requires massive dedicated resources. It's really a testament to improvements of medical care that surgery of this type can be performed with minimal risk of death and of major complications. Most patients undergoing pulmonary valve replacement will spend one or two nights in the ICU and be ready for discharge from the hospital after four or five days. Children in particular will, will continue to recover and regain strength at home. We generally consider them fully recovered at about six weeks after the operation. Most can return to non strenuous school or work activities after minimum of three to four to six weeks after the operation. So it's a, it's a pretty big hit on an active teenager's daily life routine.

Host: And you mentioned it, I think six weeks of recovery, I believe you said, needless to say it, it it's a lot, like you said to overcome in spite of the fact that you said that there's so many advancements that it's usually very successful. That's where the Harmony Transcatheter Pulmonary Valve comes in. Tell, tell us a little bit at first about what specifically this device is.

Dr. McMahon: So yes, so physicians and scientists have been working for a very long to develop a way to replace a heart valve that can be implanted without the need of open-heart surgery. While there are previous valves that have been used for patients with Tetrology, the previous valves were used only in certain circumstances for patients who had less common types of repair. The Harmony Valve is composed of a nitinol metal stent it's, so it's got a metal framework that has self-expanding properties. The stent has a polyester fabric covering and a porcine pericardial tissue valve, meaning a, the pericardium, the tissue that surrounds the heart from a pig is formed in the shape of valves. And that valve is sewn into the middle of the stent. The valve frame has a complex three-dimensional structure that allows it to hold itself in place once we implant it in the pulmonary artery. A person having the Harmony Valve Implant procedure is asleep, like they would be for a minor operation under general anesthesia. It's a one and a half to two hour procedure, most commonly. These are catheter based procedures. So, we place a catheter in the vein in the leg, from there up to the heart, through the heart and out into the pulmonary arteries.

We take pictures or angiograms to visualize the area that we need to implant the valve. Once we've done that, we then compress the valve to a small size in order to load it into a delivery catheter. And the delivery catheter system is advanced over a guide wire through the heart, out into the pulmonary artery.

The patient's heart is still beating. Their heart rate and their blood pressure is their own. We're not having to do anything artificial. So, while the heart's beating, we then deploy the valve into the main pulmonary artery and area of the native pulmonary valve. And the valve, because it's a self-expanding stent, it opens up on its own in place. And as it does that, the valve inside it also opens up and begins to work right away. Once the entire valve is opened and determined to be accurately deployed in the correct location, then it can be released from the delivery system. The patient spends one night in the hospital in a regular floor room, no need to go to an ICU and most commonly ready for discharge about 10:00 AM or noon the following day. Most of our patients are up and walking the evening of the procedure or the morning following the procedure. Medical treatment after a valve implant is aspirin to reduce the risk of blood clots forming related to the new valve. After a few days to recover at home, most, most persons are able to return to non strenuous activity at school or work within a few days and back to most strenuous physical activity after seven to 14 days.

Host: So we're talking about six weeks full recovery versus really just a few days, maybe a couple of weeks of full recovery with this new particular procedure that we're talking about. I know that's gotta be a big deal for these patients as they're, as they're recovering.

Dr. McMahon: That's a big part of it, but also a big part of it is that the family has been worried about this day for years. You know, they've been told since early on that the child is going to need another surgery and as successful as it is, in the minds of many of our, of our patients and rightfully so, it's a big, big deal. So, being able to treat the residual underlying heart condition with a transcatheter option, relieves a great deal of anxiety on the part of the patients and the families. And yes, for the young adults who have full-time jobs that we've done this procedure on, they're very grateful to be able to not have to take so much time off of work and feel pretty darn good when they go back to work.

Host: Certainly a big deal in terms of medical advancements and in terms of what it means for the patients. For you as a doctor, being able to perform this procedure and you and your colleague, Dr. Mark Law, being the first to perform this in that 10 state region of the Southeast that we mentioned, what does it mean to you? How special is that to you to play a role in this groundbreaking milestone?

Dr. McMahon: Well, I think we all want to be the best that we can be in our chosen fields and Dr. Law and I, individually got into this field because we're interested in providing the best treatment possible, the safest way. And we've known that these sort of developments and improvements in care are coming down the pathway of research and development and then clinical trials, and then release to be available for general procedures. We've known these things are coming for quite some time.

So, it's quite exciting to be able to be among the first in the country to take part in reaching this new milestone that we're able to treat patients the safest and the best way possible.

Host: And I guess having this procedure out there, with it being possible, that's a big deal for other hospitals around the country and patients everywhere who may be dealing with Tetrology of Fallot.

Dr. McMahon: Absolutely the, of course the, there's been a great deal of success with this procedure and with this valve so far. There's a company behind it that, that produces it. And they're doing a great job of, very safely moving forward with deploying the use of this valve at many of the best children's hospitals around the country and, and being important stewards of making sure that everybody gets the proper training that's necessary.

There certainly are some things that are, that are involved in this procedure that are not the same thing as what we've done over the years. There are certainly some new things that cardiologists like Dr. Law and myself have to learn, have to become more familiar with so that we are able to safely deploy this valve.

Host: Certainly a big milestone for Children's of Alabama and for everyone out there dealing with Tetrology of Fallot. Once again, Dr. William McMahon of Children's of Alabama. Thanks so much for your time.

Dr. McMahon: Thanks. It was great to talk to you.

Host: Thanks for listening to Inside Pediatrics. You can find more podcasts like this one at children'sal.org/insidepediatrics.