UAB Performing New Transcatheter Aortic Valve Replacement Procedure
In August, UAB’s Heart Team performed Alabama’s first transcatheter aortic valve replacement (TAVR). The process inserts a newly approved bioprosthetic valve percutaneously using a catheter and implants it in the orifice of the native aortic valve.
Designed by Edwards Lifesciences, the new TAVR valve received FDA approval last November. “The valve has been developed over the last 10 to 12 years, and there have been improvements made to it with its use in Europe for quite some time,” says James Davies, MD, cardiothoracic surgeon at UAB.
“The new valve is a tissue prosthesis that mounts on a metal exoskeleton,” Davies says. “The leaflets of the valve are the same as used in a standard valve replacement, but the support structure is different.”
Unlike in the open surgery approach, the patient’s damaged valve remains in place with the TAVR. “But we’re pushing the true valve out to the side, not really destroying it,” Davies says. “We use the balloon to push it out, and the exoskeleton of the prosthetic valve keeps it out of the way.”
The new valve is expected to last five years, which can’t quite match the non-mechanical valves used in open procedures. “Though some of the new TAVR ones have been out there longer than that; I think going on about seven years now,” Davies says.
TAVR gained FDA approval for use only on patients who do not qualify for the open procedure, which is about 10 to 20 percent of those with severe stenosis. “This is not a replacement for the standard aortic replacement, because we have such great success with that procedure,” Davies says. “But about 50 percent of those who qualify for TAVR would not be alive in 12 to 18 months without it.”
Because of the catheter approach in a TAVR, this procedure requires that both an interventional cardiologist and a cardiothoracic surgeon be on-hand. “This is a hybrid procedure between putting stents in and putting in valves,” Davies says. “Because of that complexity, you need two levels of expertise in the operating room.”
He and UAB interventional cardiologist, Massoud Leesar, MD, performed the first TAVR in the state. UAB has another team also in place performing the procedures.
On the UAB teams, the roles of each cardiac specialist have intermingled. “Here we chose to integrally involve the entire team,” Davies says. “We don’t think the role of the surgeon is just to open the groin and give access. We take turns doing different portions, so everyone is learning.”
Davies says the size of the sheaths creates a complexity that requires both areas of expertise. “But it’s not just that they’re very large sheaths, as large as eight to nine millimeters versus the normal two. It’s also that if the patient has a problem, it can lead to the need for open surgery.” That situation arises in less than five percent of cases, he says.
By the end of the year, one cause of that situation may be resolved with a new approach. “Right now, we access the valve through the groin, and some of those arteries are too small,” Davies says. “In the next phase, we’d open up on the left side of the chest to access the front of heart directly a trans-apical approach, so surgeons will be more directly involved.”
Having two primary experts doing the same procedure takes a willingness from both sides, Davies says. “We’re used to doing it all alone and making decisions by ourselves. But you need that input, so you have to put your ego aside. It’s like having a side-seat driver.”
To perform the procedure, a facility must outfit a hybrid operating room with the components of a standard operating room and the imaging equipment equivalent to a cath lab.
“You need that imaging expertise in the room,” Davies says. “In one portion of the procedure, you do a balloon valvioplasty, and when you transition from there to deploying the valve, it’s tricky. You need that imaging, because if you’re off, then you have a real complication.”
UAB had created their hybrid operating room a few years ago in hopes of participating in the study, but the sudden death of one of the cardiologists made that impossible. “But in that process, we had acquired the needed imaging equipment and had put in place a system to begin finding and identifying appropriate patients,” Davies says.
That put UAB ahead of other facilities in the state for performing the TAVR. In August and September, the UAB team did eleven TAVRs. They have about thirty more patients waiting to be evaluated.
“The best part of doing this procedure is seeing how well the patients look the day after surgery,” Davies says. “In August with our first four procedures, we had two 89-year-olds and two 85-year-olds who were walking the day after surgery. And they went home within three days.”
Davies thinks the next facilities to start doing TAVRS will be in Mobile and Huntsville this fall. “But no one else in Birmingham will likely have this in place before the first of the year.”