Purpose of the intervention
The aortic valve usually opens when blood is pumped from the heart to the rest of the body during contraction. Aortic stenosis is a condition where the aortic valve cannot open and close properly. This puts a strain on the heart and can lead to shortness of breath, swelling in the ankles, chest pain, dizziness and sometimes syncope.
What is percutaneous aortic valve replacement (TAVI)?
Transcatheter aortic valve replacement (TAVI) is a procedure that allows the implantation of an aortic valve using a long tube called a catheter. Usually, the catheter is inserted into a large blood vessel in the groin or through a small incision in the chest. Transcatheter aortic valve replacement (TAVI) is a procedure for patients with severe and symptomatic aortic stenosis (narrowing of the aortic valve opening). TAVI is performed in a beating heart and does not require cardiopulmonary bypass. It is approved for patients who are considered intermediate or high risk for surgical aortic valve replacement (SAVR) or are inoperable.
Prosthetic aortic valves are specially designed for this procedure. They consist of natural tissue, which is redesigned and implanted over the existing valve. The new valve starts working immediately.
The TAVI valve is made of bovine or porcine pericardium and is supported by a metal splint (frame). TAVI does not require traditional anticoagulation or "blood thinners" like mechanical heart valves.
a) Balloon catheter on the diseased valve
b) Balloon with valve in place
c) Balloon expansion for fixing the valve
TAVI approaches
There are currently four different approaches.
Percutaneous approach
This is the most common approach, used in almost 97% of cases. A sheath (hollow tube) is placed in the femoral artery (in the groin-bottom of the leg). The compressed heart valve is placed in the catheter and guided by fluoroscopy until it is placed directly into the diseased aortic valve. Once in place, the new valve is deployed to secure it in place. Once the valve is secured in place, all catheters are removed.
Often, the procedure is performed under "monitored anaesthesia care", using intravenous (IV) sedatives and pain medications, as well as local anaesthetic and without the need for endotracheal ("breathing tube" or "breathing machine") anaesthesia. A team of interventional cardiologists, imaging specialists, cardiac surgeons and cardiac anesthesiologists work together to place the valve and make sure it works properly.
The following alternative approaches are used in patients for whom the pelvic vessels are not large enough to pass the valve catheter.
Sub-key approach
This procedure is performed under general anesthesia with an endotracheal (breathing) tube in place. The subclavian approach requires appropriate sizing of either the right or left subclavian artery, located near the right or left shoulder, respectively, to deliver the valve catheter.
An incision is made at the location of the subclavian artery and a sheath (hollow tube) is inserted into the opening to the aorta. The compressed heart valve is inserted through the sheath into the aorta and placed directly into the diseased aortic valve. Once in place, the valve is deployed into position. Once your valve is functioning properly, the sheath is removed and the incision is closed.
End-to-end approach
This procedure is performed under general anaesthesia with an endotracheal (breathing) tube. During the procedure, the surgeon makes an incision between the ribs and the catheter (hollow tube) is inserted into the opening and through the top of the heart. The compressed heart valve is inserted through the sheath and placed directly into the diseased aortic valve.
Once the valve is in place, it expands into position. Once the valve is functioning properly, the sheath is removed and the chest incision is closed.
Transfemoral approach
This procedure is performed under general anaesthesia with an endotracheal (breathing) tube. During the transthoracic procedure, the surgeon makes a J-shaped incision at the top of the sternum. A sheath (hollow tube) is inserted into the opening to the aorta. The compressed heart valve is inserted through the sheath into the aorta and placed directly into the diseased aortic valve. Once in place, the valve is deployed into position. Once the valve is functioning properly, the sheath is removed and the chest incision is closed.
Brain protection
To prevent vascular strokes, a potential risk during TAVI, the TAVI team often uses the Sentinel Cerebral Protection System in appropriately selected patients. The team has been using the device since 2019. This Sentinel system was approved by the FDA in June 2017.
Special cases of a valve within a valve
Patients with previous surgical aortic SAVR replacement or surgical mitral valve replacement may experience valve degeneration after the initial surgery. For these patients, there is the option of either reoperation or percutaneous valve-to-valve (ViV) placement. For these procedures, the standard TAVI device is placed in either the aortic or mitral position. The TAVI group recommends valve-to-valve (ViV) placement when:
- A patient has a previous bioprosthetic valve
- The valve opening (prior heart valve) is the right size to support a TAVI valve
- Patient is at high risk for traditional heart surgery
What you need to know about TAVI
- Transcatheter aortic valve replacement (TAVI) is performed in intermediate or high-risk patients with aortic valve stenosis.
- In 2019 and 2020, the TAVI PARTNER-3 and EVOLUT LOW RISK trials were announced for low-risk patients randomised to either TAVI or surgical aortic valve replacement (SAVR). This trial showed equivalent results with both methods.
All patients are carefully evaluated to see if TAVI or SAVR will provide the best treatment. Regardless of the "less invasive" nature of valve replacement using TAVI, it is important to understand that this is still an important cardiac procedure and each patient should have a detailed conversation with members of the heart team about the risks and benefits on an individual basis.
Experience at the "Agios Loukas" Clinic
The "Agios Loukas" Clinic started the TAVI program in 2006 as one of the two early pioneering centers in Thessaloniki and three in Athens. Since 2012, the Clinic has become an accredited center by the KESY in the use of this specialized treatment, carefully evaluating patients from the heart team.
Between 2012 and 2021, the TAVI team performed more than 400 procedures (including >300 procedures with a transmural approach and >100 procedures with a transmural approach), with success rates greater than 98%.
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