Surgery for aortic valve disease may be performed using cardiopulmonary bypass. Minimally invasive surgery involves 3-inch incisions made in or to the right of the sternum and is is now the most common approach for isolated heart value surgery. Although aortic valve surgery is a major intervention, early surgery is important to prevent progressive ventricular dysfunction and heart failure.

Indications for aortic valve surgery

• Aortic stenosis:
  • Symptomatic patients
  • Asymptomatic patients with an aortic valve area of less than 0.8 cm² or a mean systolic gradient greater than 50 mmHg with left ventricular hypertrophy¹
• Aortic Insufficiency:
  • Symptomatic patients
  • Asymptomatic patients should also be operated on when left ventricular function begins to deteriorate (before the ejection fraction falls below 55% or the end-systolic dimension exceeds 55 mm)¹

Aortic balloon valvuloplasty

• Percutaneous balloon valvuloplasty is usually considered as palliative treatment and may be undertaken in very ill patients who cannot safely undergo surgery.²
• Recent National Institute for Health and Clinical Excellence (NICE) guidelines state that current evidence supports the safety and efficacy of balloon valvuloplasty for aortic valve stenosis in adults and children.³
• In adults, the procedure should only be used to treat patients who are unsuitable for surgery, as the efficacy is usually short-lived.
• In infants and children, critical aortic stenosis is very rare and balloon valvuloplasty is usually used palliatively until the child is old enough to have valve replacement.³

Aortic valve repair

• In the past few years, aortic valve repair has become an option for patients with bicuspid aortic valve disease and other conditions of the aortic valve.
• Aortic valve repair is performed less often and is more technically difficult than mitral valve repair.
• Aortic valve repair is an option for aortic regurgitation but not stenosis.
• The majority of leaky bicuspid aortic valves can be repaired with good results.
• Patients do not need to take long-term anticoagulant medication.
• A repaired valve can last a lifetime, but about 25% of patients will require a valve replacement within ten years.

Aortic valve replacement

From 1990 to 2000, the choice of valve replacements indicated by the United States Society of Thoracic Surgery Registry for patients less than age 60 years with aortic valve disease was: mechanical valve in 77% of patients, bioprosthetic valves in 13%, homograft valves in 5% and Ross procedure in 5%.³

Trials are currently underway in the UK to assess transfemoral aortic valve replacement (heart valve prosthesis is implanted via the femoral artery) and transapical aortic heart valve replacement (heart valve prosthesis is implanted through the apex of the heart).⁴ The evidence on transcatheter aortic valve implantation for aortic stenosis is limited; the evidence shows good short-term efficacy but there is little evidence on long-term outcomes.²

Mechanical valve replacement

• The bileaflet valve is most often used. It consists of two pyrolite carbon leaflets in a ring covered with polyester.
• Reoperations for mechanical failures or tissue ingrowth are uncommon.
• Patients will need to take an anticoagulant medication for the rest of their lives.

Bioprosthetic valve replacement

• Made of tissue, but with some artificial parts to provide additional support and allow the valve to be sewn in place.
• Can be made from pig tissue, cow pericardial tissue or pericardial tissue from other species.
• Anticoagulation is not required unless for any other associated problems.
• There is a 50% chance of the valve lasting 15 years or longer, without decline in function. The valves do not last as long in younger patients.

Homograft (allograft) valve replacement

• A homograft is an aortic or pulmonary valve that has been removed from a donated human heart.
• This is particularly useful when the aortic root is diseased or endocarditis is present.
• Patients do not need to take anticoagulant medication.
• There is lack of availability of homografts and the surgery is technically difficult.
• Homograft valves are expected to last about 15 to 20 years but are less durable in younger patients.

Ross procedure ('switch procedure')⁵

• Usually performed on patients younger than ages 40 to 50 years who want to avoid requiring anticoagulation after surgery.
• The patient's normal pulmonary valve is removed and used to replace the diseased aortic valve. The pulmonary valve is then replaced with a pulmonary homograft. The pulmonary valve is anatomically very similar to the aortic valve.
• The autograft is a living valve and grows as the child or adolescent grows, making this a good option for young patients, especially athletes. The Ross procedure is therefore a popular choice for aortic valve replacement in infants and children.⁶
• The risk of thromboembolic complications and valve infection is very low - lower than for any alternative valve prosthesis.
• The Ross procedure is technically difficult and long surgery and only recommended for young patients who would tolerate a long surgery time. The Ross procedure is not recommended for patients with tissue defects (such as Marfan's syndrome) or for patients who have an abnormal pulmonary valve.
• The risk of requiring reoperation for a leaking autograft valve is about 10% within 10 years after the operation. The risk of requiring replacement of the pulmonary homograft is also about 10% by 10 years after the procedure.

Aortic valve-sparing operations⁷

• There is an increasing use of aortic valve-sparing operations, which preserve the aortic cusps in aortic root dilation with aortic insufficiency.
• Aortic valve-sparing operations have been shown to have improved long-term survival and a reduced risk of aortic insufficiency and thromboembolic complications.

Document references

1. Shipton B, Wahba H; Valvular heart disease: review and update. Am Fam Physician. 2001 Jun 1;63(11):2201-8. [abstract]
2. Transcatheter aortic valve implantation for aortic stenosis, NICE Interventional Procedure Guideline (June 2008)
3. Balloon valvuloplasty for aortic valve stenosis in adults and children, NICE Interventional Procedure Guideline (2004)
4. Ye J, Cheung A, Lichtenstein SV, et al; Six-month outcome of transapical transcatheter aortic valve implantation in the initial seven patients. Eur J Cardiothorac Surg. 2007 Jan;31(1):16-21. Epub 2006 Nov 28. [abstract]
5. Ross DN; Replacement of aortic and mitral valves with a pulmonary autograft. Lancet. 1967 Nov 4;2(7523):956-8.
6. Alsoufi B; Aortic Valve Disease and the Ross Operation.; eMedicine, January 2009.
7. Schmitto JD, Mokashi SA, Chen FY, et al; Aortic valve-sparing operations: state of the art. Curr Opin Cardiol. 2010 Mar;25(2):102-6. [abstract]

Internet and further reading

• Oxford Textbook of Medicine 4th edition; Section 15.34.5-7; Aortic stenosis, mixed aortic valve disease and aortic regurgitation.

Acknowledgements