Surgical aortic valve replacement
The diseased aortic valve is cut out and a mechanical or tissue valve is sewn in its place.
Why it's done
- Severe aortic stenosis with symptoms (breathlessness, angina, syncope).
- Severe aortic stenosis without symptoms but with LV dysfunction, or when the patient is having other heart surgery anyway.
- Severe aortic regurgitation with symptoms or a dilating, failing left ventricle.
- Endocarditis with complications such as abscess or heart failure.
The steps
- Arrest the heart: Bypass, cross-clamp and cardioplegia as usual.
- Open the aorta: A transverse incision just above the valve (aortotomy) exposes the leaflets.
- Excise and debride: The leaflets are cut out and calcium is carefully removed from the annulus. Loose calcium can embolise to the brain, so the ventricle is protected while debriding.
- Size and sew: The annulus is sized, then pledgeted sutures go through the annulus and the sewing ring of the new valve.
- Seat the valve: The valve is lowered into place and tied down. The surgeon checks the coronary ostia aren't covered.
- Close: The aorta is closed, the heart de-aired and the patient weaned from bypass. Echo (TOE) checks the new valve.
Risks
- Stroke
- Heart block needing a permanent pacemaker (a few percent)
- Bleeding
- Paravalvular leak
- Prosthetic valve endocarditis
- Patient-prosthesis mismatch, where the valve is too small for the patient
Recovery
Similar to CABG: ICU for a night or so, home after about a week, sternal precautions for around 6–12 weeks. Mechanical valves need lifelong warfarin. DOACs aren't used for mechanical valves.
St George's Cardiothoracic Surgery Society, City St George's, University of London.