Transcatheter aortic valve implantation
A new valve is crimped onto a catheter, threaded up from the groin and opened inside the old one.
Why it's done
- Severe symptomatic aortic stenosis in older patients, or those at higher risk from open surgery.
- European guidance broadly favours TAVI from around age 75 or in higher-risk patients, with SAVR for younger, lower-risk patients. Every case goes through the heart team.
The steps
- Plan with CT: A CT scan measures the annulus, the height of the coronary arteries and whether the leg arteries are big enough.
- Access: Usually through the femoral artery, often under local anaesthetic and sedation rather than a general anaesthetic.
- Cross the valve: A stiff wire is passed across the narrowed valve into the left ventricle.
- Rapid pacing: The heart is paced very fast for a few seconds so it barely ejects, keeping the valve still while it's deployed.
- Deploy: A balloon-expandable or self-expanding valve is opened inside the old one, pushing the diseased leaflets aside.
- Check and close: Echo and angiography check position and leaks. The femoral artery is closed with a closure device.
Risks
- Permanent pacemaker (more common with self-expanding valves)
- Paravalvular leak
- Vascular injury at the access site
- Stroke
- Rare but serious: coronary obstruction, annular rupture
Recovery
Most patients are walking the same or next day and home within a few days. There's no sternotomy, which is the main appeal for frail patients.
St George's Cardiothoracic Surgery Society, City St George's, University of London.