Interventional Catheter-Based Therapies
Minimally-invasive therapies for heart valve problems are an option for those patients who are at high-risk for surgery, particularly those who have either aortic or mitral valvular stenosis. Advancement in technology also permits us to be at the cutting-edge of other minimally-invasive treatments such as closure of patent foramen ovale, atrial septal defect, ventricular septal defect and prosthetic paravalvular regurgitations.
Balloon Valvuloplasty for Valvular Stenosis
MDCA cardiologists are experts in treating congenital (birth) or acquired valvular defects by performing the most up-to-date catheter-based procedures, including balloon valvuloplasty to treat heart valvular stenosis (valve stiffening and narrowing). The two most common disorders are mitral valve stenosis and aortic valve stenosis. The mitral valve sits between the left atrium and left ventricle, and the aortic valve (in the left ventricle) opens to allow blood flow into the aorta and throughout the body.
Valvuloplasty involves a catheter being passed through the femoral vein in the groin and then gently threaded into the heart with the aid of x-ray fluoroscopy. In balloon mitral valvuloplasty to treat mitral valve stenosis, a catheter with a balloon on its tip is passed into the left atrium and then into the mitral valve. The cardiologist then inflates the balloon several times to widen the valve, and then removes the catheter. Balloon aortic valvuloplasty to treat aortic valve stenosis uses the same procedure. Balloon pulmonary valvuloplasty is also done in a similar manner to treat pulmonary valve stenosis. The pulmonary valve, located in the right ventricle, opens to allow blood flow into the pulmonary artery and then to the lungs for oxygenation.
Percutaneous PFO, ASD and VSD Closures
Other minimally invasive heart catheterization procedures involve closing holes between heart chambers due to congenital defects. It is not clear what causes these defects from birth that can result in non-oxygenated blood mixing with oxygenated blood in the heart chambers, thus making the heart work harder.
Common congenital openings include atrial septal defects (ASD) involving the upper heart chambers, and those affecting the lower chambers known as ventricular septal defects (VSD). Patent foramen ovale (PFO) is a flap over a small hole between the left and right atria that exists before birth, but in most cases, closes after birth. PFOs that don’t close after birth can also result in oxygenated and non-oxygenated blood mixing. In addition, blood clots that can occasionally form in veins can travel through a PFO to reach the brain causing a stroke or mini-stroke (TIA).
While small holes often cause no symptoms and need no treatment, larger openings are more serious and can be closed through heart catheterization. During the procedure, the hole in the heart chamber is first measured using a balloon at the end of the catheter. This is followed by what’s called a closure device, made of wire mesh and covered by a membrane or fabric, which is expanded over the hole. Within a few months after the procedure, the body’s natural reaction eventually covers the device with heart tissue and it becomes part of the heart wall. Patients who are not likely candidates for such procedures are those where the hole is too big or if the patient has structural heart defects, blood clots or other complications. In these cases, open heart surgery is the preferred option.
Paravalvular Regurgitation Repairs
A backward regurgitation of blood flow occurs in a small percentage of patients who undergo surgical valve replacement. The backflow, however, is not due to a faulty valve but instead to a cavity or hole that has developed between the prosthetic valve and heart wall tissue where the valve was implanted.
Newly developed catheterization procedures can help seal the holes. A catheter is threaded through an artery and into the heart. On the tip of the catheter is balloon which is pulled into the cavity by the force of the leak, identifying the hole. Using X-ray and live 3D echocardiogram images, a wire with a stent is then guided to the location of the hole around the artificial valve. The stent, covered with an impermeable membrane, is then place over the leak and thus sealing the hole. For many patients this procedure will improve their symptoms of heart failure (usually shortness or breath) or anemia (low blood count).