How Is TAVI Performed? A Step-by-Step Guide to the Procedure

TAVI, or transcatheter aortic valve implantation, is a minimally invasive procedure used to replace a diseased aortic valve without the conventional open-heart surgery required for surgical aortic valve replacement.

For many patients, particularly those with severe aortic stenosis who are suitable for a transcatheter approach, TAVI can provide a way to replace the narrowed valve through a catheter. The new valve is delivered in a compressed form and positioned inside the patient's existing aortic valve.

If you are learning about the treatment as part of your care journey, our detailed guide to TAVI/TAVR treatment provides an overview of the procedure and its role in treating aortic valve disease.

What happens before the TAVI procedure?

The TAVI procedure begins well before the patient enters the catheterisation laboratory. Careful planning is essential because the replacement valve has to be selected and positioned according to the patient's individual heart and blood-vessel anatomy.

The Heart Team usually reviews:

• The severity of aortic stenosis
• Heart function and valve anatomy
• The size and shape of the aortic valve opening
• The position of the coronary arteries
• The condition and size of the blood vessels that may be used for catheter access
• Other heart conditions
• Overall health and procedural risk

Detailed imaging, particularly echocardiography and CT scanning, plays an important role in planning the procedure. These investigations help the team determine whether TAVI is suitable, which access route is safest and what size and type of valve should be used.

Step 1: Preparing the patient

On the day of TAVI, the patient is prepared in a specialised cardiac procedure area or catheterisation laboratory. Monitoring equipment is attached to continuously track heart rhythm, blood pressure, oxygen levels and other vital signs during the procedure.

The exact type of anaesthesia or sedation depends on the patient's condition, the access route and the centre's procedural approach. Many transfemoral TAVI procedures can be performed using local anaesthesia with sedation, while general anaesthesia may be required in selected situations. The access area, most commonly the groin, is cleaned and prepared using sterile techniques.

Step 2: Accessing the blood vessel

For most patients, the replacement valve is delivered through the femoral artery in the groin. This is known as the transfemoral approach and is the usual access route when the blood vessels are suitable.

A small opening is made to access the artery, and a specialised sheath is introduced. The catheter and other instruments can then be guided through the blood vessel towards the heart.

Because the procedure uses a catheter rather than requiring the chest to be opened, transfemoral TAVI does not involve the large chest incision associated with conventional surgical valve replacement.

If the femoral arteries or other blood vessels are unsuitable, alternative access routes may sometimes be considered. The appropriate route is determined during the pre-procedure assessment.

Step 3: Guiding the catheter towards the heart

The catheter is carefully advanced through the blood vessel towards the aorta and the diseased aortic valve. Doctors use continuous imaging to guide the equipment. X-ray imaging and contrast angiography help show the position of the catheter and the surrounding structures, while echocardiographic imaging may also be used when appropriate. The purpose is to guide the replacement valve accurately to the exact location where it needs to be deployed.

Step 4: Crossing the diseased aortic valve

A guidewire is carefully passed across the narrowed aortic valve. Once the wire is positioned safely, it provides a pathway over which the delivery system carrying the replacement valve can be advanced.

This is an important technical step because the wire and delivery system must be positioned carefully within the heart while avoiding injury to surrounding structures.

Depending on the patient's anatomy and the type of valve being used, additional preparation of the native valve may be performed before the replacement valve is implanted.

Step 5: Positioning the replacement valve

The replacement valve is compressed onto a delivery system so that it can pass through the catheter. Once the delivery system reaches the aortic valve, the new valve is positioned carefully within the diseased native valve.

This positioning has to be precise. The new valve needs to sit securely at the correct depth so that it can open properly and allow blood to flow from the left ventricle into the aorta. Imaging is used throughout this stage to confirm the position of the valve before it is released.

Step 6: Deploying the new valve

Once the valve is correctly positioned, it is expanded or released. Depending on the valve system, deployment may involve a balloon that expands the valve or a self-expanding mechanism that allows the valve to gradually open into position.

As the replacement valve expands, it presses against the calcified leaflets of the diseased native valve and takes over its function. The original valve is generally not surgically removed. Once deployed, the new valve creates a new pathway for blood to leave the heart and enter the aorta.

Step 7: Checking that the valve is working properly

Implanting the valve is not the end of the procedure. The team immediately checks its position and function.They assess whether:

• The replacement valve is positioned correctly
• The valve is opening and closing appropriately
• Blood is flowing properly through the new valve
• There is significant leakage around the valve
• The coronary arteries remain unobstructed
• There are any signs of complications

Imaging and pressure measurements can help the team determine whether the valve is functioning as expected. If necessary, additional adjustments may be performed before the procedure is completed.

Step 8: Removing the catheter and closing the access site

Once the team is satisfied with the valve's position and function, the delivery system and other catheters are removed. The access site in the artery is then closed using appropriate closure techniques. Because the procedure is usually performed through a blood vessel rather than through the chest, the access wound is considerably smaller than the incision required for open-heart valve surgery.

How long does a TAVI procedure take?

The duration varies depending on the patient's anatomy, the valve being used, the access route and whether any additional procedures are necessary.

The procedure itself may be completed within a relatively short period, but the total time spent in the procedure area also includes preparation, anaesthesia or sedation, imaging, monitoring and recovery.

Patients and families should therefore not judge the complexity of TAVI simply by the length of the procedure. Considerable planning and monitoring take place before and after the valve is implanted.

What happens immediately after TAVI?

After the procedure, the patient is moved to a recovery area or monitored cardiac unit, depending on their condition and the hospital's care pathway. The medical team monitors:

• Heart rhythm
• Blood pressure
• Heart and valve function
• The catheter access site
• Signs of bleeding or vascular complications
• Kidney function and other relevant blood tests

Heart rhythm monitoring is particularly important because changes in the electrical conduction system can occur after aortic valve implantation. Some patients may require a permanent pacemaker if significant conduction problems develop.

What happens before going home?

Before discharge, the medical team evaluates the patient's recovery and makes sure there are no significant complications.

The team may perform further examinations or echocardiography to assess the newly implanted valve and heart function. The access site is also checked carefully.

The length of hospital stay varies. Some patients, particularly those who recover smoothly after transfemoral TAVI, may be discharged relatively soon after the procedure. Older patients or people with other medical conditions may require longer monitoring.

Does TAVI always use the groin?

No. The transfemoral route is the most common approach when the femoral arteries are suitable, but it is not the only possible access route.

If the blood vessels are too narrow, heavily diseased or otherwise unsuitable, the Heart Team may consider another route based on the patient's anatomy and the available valve system.

The access route is therefore decided before the procedure using detailed imaging rather than simply being selected on the day of treatment.

Is the patient's old aortic valve removed?

Usually, no. One of the defining features of TAVI is that the replacement valve is positioned inside the existing diseased aortic valve. As the new valve expands, it pushes the native valve leaflets aside and takes over their function. This is different from surgical aortic valve replacement, in which the surgeon removes the diseased valve and implants a new one.

What can make the procedure more complex?

Although TAVI is minimally invasive, it remains a technically demanding heart procedure. Procedural complexity can be influenced by factors such as:

• Unusual aortic or valve anatomy
• Heavy valve calcification
• Small or difficult blood vessels
• Bicuspid aortic valve anatomy
• Low-positioned coronary arteries
• Severe heart dysfunction
• Other significant heart or vascular disease

What makes TAVI different from open-heart valve replacement?

The biggest difference is how the new valve is delivered. In TAVI, the valve is carried to the heart through a catheter, most commonly through the femoral artery. The diseased native valve generally remains in place.

In surgical aortic valve replacement, the chest is opened, the patient is placed on a heart-lung machine, the diseased valve is removed and a replacement valve is surgically sewn into position.

This difference is why TAVI can offer a less invasive treatment pathway and, for appropriately selected patients, a faster early recovery. However, the choice between TAVI and surgery depends on the individual patient's anatomy, age, overall health and long-term treatment needs.

The Bottom Line

TAVI is performed by delivering a compressed replacement aortic valve through a catheter and positioning it inside the patient's diseased native valve. For most suitable patients, the catheter is introduced through the femoral artery in the groin and guided through the blood vessels to the heart.

The procedure involves several carefully controlled stages: preparing the patient, obtaining vascular access, guiding the catheter to the heart, crossing the diseased valve, positioning and deploying the replacement valve, checking its function and closing the access site.

Although TAVI does not require conventional open-heart surgery, it remains a sophisticated cardiac procedure that requires detailed imaging, precise valve positioning and continuous monitoring. The patient's anatomy and overall health determine how the procedure is planned and whether the transfemoral route is appropriate.

For patients and families, understanding these steps can make TAVI easier to visualize: the new valve is brought to the heart through a catheter, placed inside the diseased valve, expanded into position and then carefully checked before the procedure is completed.