Although aortic valve bypass surgery has been around for quite some time, very few surgeons in the world recognize it as a viable treatment option for patients diagnosed with aortic stenosis. Below, Dr. James Gammie, a cardiac surgeon at the University of Maryland Heart Center, answers some frequently asked questions about aortic valve bypass surgery and how it can be used to successfully treat aortic stenosis in the older population.
As we get older, in a certain percentage of the population, the outflow valve from the main pumping chamber of our heart gets progressively narrower. This narrowing of the valve is known as aortic stenosis, and it presents a real problem for patients because it chokes off the blood leaving the heart. The traditional treatment for aortic stenosis has been open heart surgery, which involves a surgeon making a large incision in front of the chest. Open heart surgery has been performed for more than 50 years now.
Typically, when patients have aortic stenosis, they will experience the following symptoms:
To perform open heart surgery, the surgeon will put the patient on a heart-lung machine, crack open the patient's chest and stop the heart. Once the heart is stopped, the surgeon can cut out the old aortic valve and sew in the new valve. This operation relieves the blockage and patients often feel much better afterwards.
At the University of Maryland Heart Center, we have explored an alternative to open heart surgery that we call aortic valve bypass surgery. The idea behind aortic valve bypass surgery is pretty simple -- rather than replacing that narrowed valve as we do in open heart surgery, we do an end-run around it; we bypass it. Aortic valve bypass surgery has been around for a long time, but it hasn't been widely used. In fact, there are only a handful of surgeons that perform this procedure in the world.
The human heart is shaped like a football with the narrowed valve at one end. To perform aortic valve bypass surgery, the surgeon makes a small incision on the left-side of the chest, goes to the opposite end of the heart and "bypasses" the narrowed valve by sticking a small tube in the tip of the heart. Inside of this tube is a standard, one-way replacement pig valve. The surgeon runs this tube down to the main blood vessel in the back of the chest, creating a "back door" that previously did not exist to allow blood to get out of the heart.
There are a number of patients who cannot undergo traditional open heart surgery for a variety of reasons, and aortic valve bypass surgery offers a great alternative for these higher risk patients. For example, some patients have a lot of calcium build-up in the main blood vessel coming out of the heart. We call that a porcelain aorta. In cases involving a large amount of calcium build-up in the aorta, surgeons do not want to put a clamp on that blood vessel or stick a tube in it for the heart-lung machine; that's a very dangerous situation, and until recently, those patients had no alternatives and have had to simply go on with the narrowed valve. As you can imagine, the outcomes were not very good. Aortic valve bypass surgery offers an alternative to these patients who previously had no other options. We also think that elderly patients -- for example, those who have had strokes or who have a lot of scar tissue from previous heart surgeries and open bypasses -- are also good candidates for aortic valve bypass surgery.
Aortic valve bypass surgery has a number of advantages compared to traditional open heart surgery. These advantages include:
We think all of these things, in some way, make aortic valve bypass surgery a better operation than traditional open heart surgery; it is clearly an alternative.
At the University of Maryland Heart Center, we've performed aortic valve bypass surgery in over 60 patients. This operation has a long history. There are patients alive today who have had an aortic valve bypass in place for more than 25 years. It is a time-tested approach; we know that it works and we have patients of our own who are out about six years out from when we started performing this operation eight years ago.
Here at the University of Maryland Heart Center, we are focused on advanced technology and one of our areas of expertise is robotic surgery. We have a robot, which is a machine that allows us to work through very tiny ports and to do all of the things that we normally do in traditional open surgery, except through much smaller incisions.
Absolutely! The robot-assisted approach to aortic valve bypass surgery exceeded all of my team's expectations and will continue to be used on future patients. The process of sewing the bypass graft into the aorta in the back of the chest was actually much easier with the robot than it was with an open approach. In addition, the robot provides better magnification; we can see things better through the robot than we can with open surgery. Even with the first case, this approach brought significant benefits and it really was a great way to perform this procedure. We're very enthusiastic to continue moving forward.
With any procedure, it takes time to understand who benefits most from an operation. The way we do that is we look at outcomes and we look at clinical trials. Although we have a bit of a bias that this operation is a better alternative for all patients, we haven't proven that quite yet. Typically, we have performed this operation on higher risk elderly patients. As a result, we would be more inclined to perform a more conventional operation on a healthy 50-year-old patient. However, for a 75 or 80-year-old patient who is particularly interested in avoiding being on the heart-lung machine or who is avoiding having his or her heart stopped, we think this is a really good option.