Table of Contents
Clinical examination
- Metallic valves
- Metallic mitral valve: S1 sounds metallic
- Metallic aortic valve: S2 sounds metallic
- There is often a click audible without a stethoscope
- Tissue valves
- Relevant heart sounds may be normal, loud or quiet
- Systolic flow murmurs are normal for aortic valve replacements
- Assess for valve function (signs of regurgitation of replaced valve), cardiac decompensation (signs of heart failure), and signs of infective endocarditis
- Also look for signs of over-anticoagulation (bruising) and anaemia (haemolysis)
Indications for surgery
- Left-sided valve dysfunction
- Any valve: associated LVF, symptomatic
- If regurgitation, also: acute onset, associated LV dilation
- If mitral, also: presence of pulmonary hypertension
NB: for MR, valve repair is preferred when possible; for MS, balloon valvuloplasty is preferred unless contraindicated (i.e. coexistent MR, thrombus or calcified valve).
- Infective endocarditis
- Associated heart failure
- Uncontrolled infection (fistula, enlarging vegetation, false aneurysm, aortic root abscess, persistently positive blood cultures, fungal/multidrug-resistant organism)
- High embolic risk (persistent large vegetation)
NB: If prosthetic valve, surgery also indicated if: <2 months post-op, valve dysfunction or Staphylococcus aureus infection.
Types
- Tissue valve
- Usually porcine xenograft
- Needs replacing after 10-15 years; sooner if patient is active
- No need for warfarin
- Recommended for older people, people with low life expectancy and females of child-bearing age
- Mechanical valve
- Longer lasting (older valves 20-30 years, newer valves >30 years)
- Lifelong warfarin
- Makes a quiet clicking noise
- Recommended for younger people (<60 years) so they don’t need repeat surgeries (unless female and of child-bearing age because warfarin is teratogenic)
Procedure
- Pre-operative: transthoracic ± transoesophageal echo, coronary angiography
- May be performed by:
- Open surgery: via midline sternotomy
- Minimally invasive surgery
- Aortic valve: via right anterior mini-thoracotomy (2nd intercostal space) or mini-sternotomy
- Mitral valve: via right lateral mini-thoracotomy (below nipple or in breast crease)
- Patient is put on cardiopulmonary bypass while valve is replaced
NB: if there is also coronary artery disease, CABG is usually performed concurrently – check the legs for a vein grafting scar.