Believe it or not, this technology allows doctors to place a new valve in your heart without your having to undergo open heart surgery.  The technology is already being used in Europe and Canada.  Currently, the procedure is undergoing investigational studies by the FDA in the United States.

Below is the Edwards Lifesciences SAPIEN percutaneous valve.  It is the one that most likely will be first to be approved in the U.S.  It consists of a bovine pericardial valve that is held together by a collapsible stainless steel frame.  At this point in time, almost all of the percutaneous valve procedures are done for aortic stenosis --blockage of the aortic valve.

Another percutaneous aortic valve that has been implanted overseas is the Medtronic CoreValve shown below.

It also consists of a bovine pericardial valve but it's held together by a self-expanding nitinol stent.  The Medtronic CoreValve will soon be part of investigational studies in the U.S.

So, how do they put an aortic valve in your heart without surgery?

So far, there are two approaches:  "trans-femoral" and "trans-apical."

In the trans-femoral approach, a catheter in placed in an artery in the groin, similar to a standard cardiac catheterization.  The difference is that currently the catheter sizes are quite large, so an incision is required to place these catheters.  In time it is likely that the catheter sizes will decrease.

The first step is to take a balloon and bust open the aortic valve.  After that, the percutaneous valve is put in place and a second balloon expands the new valve, cementing it into position.

Below is an animation of the procedure provided by Edwards Lifesciences.

Below is a patient who was deemed too high risk for conventional aortic valve replacement.

You're watching the fluoroscopy (moving x-ray) of the valve being opened in place by the balloon.  The valve and balloon are inserted via the artery in the groin and followed on the x-ray until it lays perfectly across the old valve.

You might ask, "What happens to the old valve?"  Well, that's a great question.  It's simply gets pushed out the way with the new valve taking it's place.

That's actually one of the controversies about this procedure.  Is this "valve inside a valve" technique as safe or as durable as the conventional techniques of replacing a valve...  see my discussion below.

Sometimes the femoral (groin) vessels are too diseased to allow for catheters to be placed.  In addition, many older patients have a lot of calcified plaques all along the aorta leading back to the heart.

The trans-apical approach alleviates the worry of injuring the leg vessels or causing a stroke by putting catheters through the aorta.  By making a small incision in the left chest (the same incision we make for "minimally invasive heart surgery"), the surgeon can place the percutaneous valve directly through the apex of the heart, as shown in the video below...

This so-called "antegrade" approach is becoming the preferred method in Europe with placement times consistently be completed in less than 45 minutes!  There are also some reports that the stroke rate may be less with the trans-apical approach.

This patient has a completely calcified aorta making both the convention open heart surgery and the femoral trans-catheter approach inoperable.

You can see the catheter entering the heart from right to left across the apex with the catheter remaining perfectly still across the aortic valve.

In the femoral approach, the valve and balloon are on a long flexible catheter which makes it harder to maneuver.  In the trans-apical approach, the catheters can be more firm and thus more stable with regards to quick and perfect positioning.

It may seem risky to put a hole in the apex of the heart and to suture it closed, but actually it's a very old technique that goes back almost to the beginning of heart surgery.  Heart surgeons are used to placing sutures and catheters in the heart, of course.

Percutaneous (Trans-Catheter) Valves and the Hybrid Approach to Heart Surgery

One of the issues with any new, less invasive technology is trying to determine who will perform the procedure.

For example, heart surgeons were trained to perform open heart valve surgery.  Interventional cardiologists were trained to perform catheter-based procedures.  So, the big question is, "Who should perform trans-catheter valve surgery?"

The answer is complex and quite frankly, the future is unknown.  However, for now, the philosophy is that these procedures should be done by both the surgeon and the interventional cardiologist working together as a team --the so-called "hybrid" approach.

And, to that point, across the globe hospitals are actually building what are known as "hybrid operating rooms."  These are oversized operating rooms that are equipped with both surgical and x-ray equipment.  In other words, these rooms combine all of the x-ray technology found in the cardiac catheterization laboratory with all of the equipment and safety of an operating room.

The Hybrid Operating Room

The hybrid operating room is being used by a number of major centers already performing these procedures, including Leipzig, Germany, and Quebec, Canada, as well as at investigational sites in the U.S. such as the University of Pennsylvania and Columbia.

The hybrid operating room may be important for both accuracy as well as safety.  The high-tech x-ray equipment and 3-D echocardiography, allows for precise placement of the percutaneous valves.  While these procedures are "less invasive" they are still very high risk.  If something goes wrong, it goes wrong quickly and we must be able to immediately convert to a conventional open approach.  The hybrid operating room is fully equipped to handle any eventuality. 

Will percutaneous valves replace open heart surgery?

It would seem unlikely at this point (at least I hope not until I pay for my kids' college education!).  Keep in mind that coronary artery stenting has not eliminated the need for coronary artery bypass surgery and I suspect there will be a similar balance with percutaneous valves.

For now, these procedures are only being done in the most high risk of patients --that is, patients who are deemed too high risk for conventional techniques.

The reason is, in part, because we really don't know the long term success or safety of these new and, quite frankly, experimental procedures.

For example, we already know that most patients who have received a percutaneous, trans-catheter aortic valve are left with what is known as a "para-valvular leak" or a leaking of blood around the new prosthetic valve as shown below:

This most likely occurs because the original bad valve, full of calcium and debris is left behind, as the new valve is simply placed within the old valve.  This can lead to long term instability of the valve or possibly the risk of infection to the new valve, known as prosthetic endocarditis.  It could take 10 or more years from now to know the true results.

There are many other risks and unknowns about the technology as well.  That's why at this point in time, the safest and most reliable procedure for aortic valve replacement remains the conventional open replacement for the majority of patients.

Preparing for the future...

There is no doubt that "hybrid" cardiovascular procedures and high-tech devices are here to stay.  The key to the success of these procedures is to breakdown the barriers that historically have separated different specialties in medicine and surgery.  What is needed is not just hybrid procedures and operating rooms, but "hybrid cardiovascular centers."

In the past, hospital organizations looked like this:

Basically, cardiology was solely in the department of medicine, cardiac surgery in the department of surgery, anesthesia in the department of anesthesiology and so on.  Traditionally, patients requiring an invasive procedure ended up in one silo of care or the other.  Yet there are components of each silo that are advantageous to the patients.

I believe the future should be one in which there is a virtual heart hospital within the hospital network such that the patient benefits from a collaborative effort of all specialists working together as a team, as illustrated below:

The goal is to optimize patient care.  New technology costs a lot of money and with each new advance comes potential risk to patients until long-term studies can prove if the new technology is actually beneficial or not.

With the health care dollar already being stretched to the point of a crisis, the only chance to provide the best, most cost-effective care to our patients is by working together... surgeons, cardiologists, hospital administrators, and so on.

It's all about the team approach...