May 29, 2016
The thought of having heart surgery can be frightening no matter the odds, but as science continues to press forward, the advancement of minimally invasive procedures is changing the outlook for patients and health care professionals.
Surgeries that once required months of downtime are being reduced to mere days, and for some high-risk patients who need a new heart valve, transcatheter aortic valve replacement (TAVR) is the minimally invasive process that can decrease recovery time. “TAVR is a procedure that changes the conventional methods for aortic valve replacement, and with a very high level of success,” said Jeffrey Levisman, MD, interventional cardiologist, Director of TAVR program at MountainView Hospital.
What is a valve replacement?
There are four valves in the heart: the aortic valve, the pulmonary valve, the tricuspid valve and the mitral valve. Any of these valves can be replaced if necessary, but an aortic valve replacement is the most common because, unlike the others, the aortic valve cannot be treated with medication.
Most aortic valve replacements require open-heart surgery. During the procedure, the patient is put under anesthesia and the surgeon makes a long incision in the chest (usually eight to 10 inches) before dividing the breastbone and exposing the heart. From there, the surgeon removes the damaged valve and sews a new valve in its place. The surgery typically takes three to six hours, and the healing time can last a couple weeks to a couple months, depending on the patient.
What causes aortic valve problems?
There are two main reasons someone may need an aortic replacement: aortic stenosis and aortic regurgitation. Aortic stenosis is when the valve has narrowed (because of age, birth defects, infections, etc.), and aortic regurgitation is when the valve leaks, allowing blood to return back into the heart rather than moving through the rest of the body. Both conditions can be life-threatening if not treated properly.
How does the transcatheter aortic valve replacement process work?
Using a method somewhat similar to a heart stent surgery, the minimally invasive TAVR method uses a collapsible replacement valve that is inserted into the heart via a catheter through the groin. The replacement valve is made of biological material encased by a tiny wire net, which is what allows it to collapse. Once the valve is in place, it is expanded and the catheter is removed.
“The entire procedure takes about two hours, including the anesthesia, but the actual deployment of the valve only takes about 10 seconds,” Levisman said.
After surgery, patients usually stay in the hospital for three to five days for monitoring, though Levisman notes that some patients have been able to leave as soon as one day later. “It just depends on the specifics of the patient’s case and their overall wellness,” he said.
The Food and Drug Administration has approved the TAVR method for patients who are classified as high-risk or inoperable. This usually means the patient is too weak to endure and recover from a full open-heart surgery. “TAVR gives some patients a potentially life-saving option that they likely wouldn’t have had before. And going forward, we’re hopeful that this method will be approved for more patients, as well,” Levisman said.
Because the procedure is still so new — it received initial FDA approval in 2011 — it requires a team of people to determine whether it is right for each patient. Levisman attributes the procedure’s success, in part, to this highly collaborative process.
Where do replacement valves come from?
Replacement valves are either mechanical or biological. A mechanical valve is manmade and lasts longer than biological valves in most cases, though mechanical valves also require the lifelong use of blood thinners.
Biological valves are tissue valves that come from animals, most often from pigs and cows. Biological valves last 10 to 20 years and usually do not require long-term medication.
Rarely, replacement valves from human donors can be used, but that is an option usually reserved for patients who have an illness that affects the valve.