Questions and Answers about Percutaneous Treatments for Valve and Aortic Disease
Director, Center for Aortic Surgery
Director, Marfan Syndrome and Connective Tissue Disorder Clinic
Specialties: Adult cardiac surgery; cardio-aortic and aortic surgery, including combined valve and aneurysm surgery; minimally invasive mitral and aortic valve surgery; blood conservation; prevention of stroke and paralysis after aortic surgery; Marfan syndrome; peripheral vascular surgery; and the Maze procedure.
Hello I’m Lars Svensson one of the surgeons at the Department of Thoracic and Cardiovascular Surgery at the Cleveland Clinic, and I’m heading up one of our research projects on percutaneous valves together with our Cardiology colleagues. This is really an exciting field for us in Cardiology and Cardiac Surgery because we looking at new ways of treating cardiac disease. As you perhaps know for most patients who have an aortic, mitral, or tricuspid valve disease what we have to do is open up our patient’s chest to repair or replace a valve. The results for that are excellent and, for example, for aortic valve we can do that with a .6 % of death, and for mitral valve its less and we ran usually at .5 % risk of death with minimally invasive mitral valve repairs or aortic valve replacements. We also do a lot of aortic valve repairs particularly with patients with bicuspid valves, or Marfans Syndrome.
However, there are a lot of patients, particular older patients, in whom we find it very risky to operate on those patients for various reasons. For example, if a patient has had big doses of radiation to the chest or they’ve had multiple heart operations previously, or they have got other reasons, for example, bad lung disease, and they’re on home oxygen. [For these] patients, we approach open surgery with a lot more caution. There are techniques that we use to do these operations. But they are patients we prefer not to have to operate on because of the risks. So, we have been looking at ways of trying to operate on these patients without having to open the chest. And that’s how the percutaneous valve techniques have been developed and we’ve been doing this now in the animal lab - doing research on replacing aortic and treating mitral valve disease in the laboratory. We’ve been able to develop techniques now that we can approach these valves without having to open patient’s chests.
We have several studies now at the Cleveland Clinic in which we’re enrolling patients in these research protocols. These are Institutional Review Board approved protocols, and they’re also approved by the FDA. Now for example, for the aortic valve what we can do in selective patients who are typically at this stage high-risk patients for open operations. We will go in through the femoral artery in the groin and snake a catheter and a wire to the aortic valve. Then we take a valve that is seated on a balloon which hasn’t been inflated, and we then feed it up under x-ray screening, up to the aortic valve and when we know where in the right position, we get the heart to race faster so it’s not pumping as much and we then blow up a balloon and those seats the new metal valve which has biological leaflets in position.
Surprisingly to us, particularly in the surgical community, this has worked out very well, and there are obviously risks. The risk is higher for somebody who is having a routine open heart operation, but it is an option in high risk patients. So we are enrolling patients in this study. We will be very careful in whom we select for these operations but that is one approach. Now, for the mitral valve we have two options. One is to go into the vein that snakes around the back of the heart that is known as the coronary sinus. And what we do, there are several approaches, but the one we’re using here is we put in flexible wires into the coronary sinus and by using them we can tighten up the mitral valve so if its leaking we can improve that an reduce amount of leakage.
This is one option that we’re starting and will be in interesting on to see how it develops in the long term. Another option, which is based on a surgical technique, is known as the Alfieri stitch. We go in with a catheter, we go across the septum, that’s the wall between the two filling chambers; the left and right filling chambers. Then we approach the mitral valve and put a little clip on it.
Initially what we do is we put a temporary suction device and clip there to see if the valve leaks once we bring the leaflets together. If it looks pretty good, we put a permanent clip on. And we use echo and radiology and geography techniques to see that it’s working. We can, in fact, remove that clip if we’re not happy with its positioning. And if it looks pretty good, we then leave that in position. And the six month data that we have now is pretty good, its still early but its still an experimental approach that allows some patients not to have to have their chests opened to have open heart surgery.
These are new techniques that we’re developing apart from obviously in the aorta now for many years we’ve been using what are called endovascular stent grafts. Where we go in through typically the femoral artery and put new tubes into the aorta to treat aneurysms in either the abdominal aorta or in the part of the chest aorta between the artery to the left arm and going down to the arteries to the stomach and intestines. So these are new exciting developments that are potentially and option for more selective patients and we can certainly screen patients to see if this is something that you may be a candidate for.
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