Valve-in-Valve Transcatheter Aortic Valve Replacement (TAVR) represents an advanced, minimally invasive cardiac procedure designed to address failing heart valves. This specialized technique offers a less invasive alternative to traditional open-heart surgery for patients who have previously undergone a heart valve replacement. It involves implanting a new artificial valve within an existing, failing prosthetic valve.
When a Heart Valve Needs Replacing Again
Heart valves, whether natural or surgically implanted, can deteriorate over time. Bioprosthetic valves, often derived from animal tissue, are commonly used in initial valve replacement surgeries due to their lower risk of blood clot formation compared to mechanical valves. However, these tissue valves are not designed to last indefinitely and typically have a lifespan of 10 to 15 years before they begin to degenerate.
The degeneration of a bioprosthetic valve can manifest in two primary ways: it may become narrowed, a condition known as stenosis, due to scarring or calcification. Conversely, a leaflet within the valve might fail to close completely, leading to regurgitation. When either of these issues significantly impairs the valve’s function and causes symptoms, a re-intervention becomes necessary to restore proper cardiac function. Factors such as younger age at the time of the initial implant, patient-prosthesis mismatch (when the implanted valve is too small for the patient’s body size), and comorbidities like diabetes can accelerate this deterioration.
The Valve-in-Valve TAVR Procedure
The Valve-in-Valve TAVR procedure places a new transcatheter heart valve inside a previously implanted, failing bioprosthetic valve. This technique avoids the need for repeat open-heart surgery, which carries higher risks, especially for older or more fragile patients.
The procedure typically begins with a small incision, most commonly in the femoral artery in the groin, although other access points like the chest or neck may be used if the femoral artery is unsuitable. Through this incision, a thin, flexible tube called a catheter is inserted and guided through the blood vessels to the heart. The new, collapsible replacement valve is then threaded through the catheter.
Once the new valve reaches the site of the old valve, it is carefully positioned and then expanded. Some valves are expanded using a balloon at the catheter tip, while others are self-expanding. As the new valve expands, it pushes the leaflets of the old valve aside, securing itself firmly within the existing valve’s structure. The new valve then takes over the function of regulating blood flow. After the new valve is confirmed to be functioning correctly and any potential leaks are addressed, the catheter is removed, and the incision is closed.
Who is a Candidate and What to Expect
Patient eligibility for Valve-in-Valve TAVR is determined through a comprehensive evaluation by a multidisciplinary heart team, which includes interventional cardiologists, cardiac surgeons, and other specialists. Generally, candidates are individuals with a previously implanted bioprosthetic aortic valve that has degenerated, causing severe symptoms like shortness of breath or chest pain. Factors such as the patient’s age, overall health status, and the specific characteristics of their existing valve, including its size and design, are considered. While initially reserved for high-risk surgical patients, TAVR is now approved for a broader range of patients with severe aortic stenosis. Patients with certain conditions, such as a recent heart attack within the last month, severe weakening of heart chambers, or active infections, might not be suitable candidates.
The patient experience with Valve-in-Valve TAVR generally involves a shorter hospital stay and faster recovery compared to traditional open-heart surgery. Recovery time can vary, but most individuals can gradually return to light activities within days of the procedure, with many resuming daily tasks sooner than with conventional surgery. Significant improvement in energy levels and a reduction in fatigue are often noticeable within about a month. Patients are typically advised to avoid heavy lifting or strenuous physical activity for at least one week, or longer depending on the catheter insertion site. Regular follow-up appointments, including echocardiograms and bloodwork, are scheduled to monitor the new valve’s function and the patient’s overall progress.