Aortic Valve Replacement: A Patient Guide
 
The Aortic Valve

The aortic valve is one of the four valves of the heart. The other three are the tricuspid, the pulmonary and the mitral valves. The aortic valve is located between the left ventricle of the heart and the aorta. It normally has three cusps or leaflets, while approximately 2% of the population have an aortic valve with two leaflets (bicuspid).
The aortic valve opens fully when the left ventricle contracts (systole) allowing blood to be expelled forward into the aorta. The aortic valve closes when the contraction ends (diastole) preventing blood from flowing backwards into the left ventricle.

The term aortic valve disease includes conditions such as stenosis, regurgitation or mixed disease.
 
Aortic Valve Stenosis

The aortic valve might sometimes become thickened with age. Its cusps become calcified and immobile leading to narrowing (stenosis) of the valve. As a result, the heart pumps blood under high resistance leading to symptoms such as shortness of breath, chest tightness and dizzy spells. If left untreated, aortic valve stenosis results in thickening of the left ventricle followed by failure of its function.
 
Aortic valve regurgitation (insufficiency) 

In this condition, the aortic valve does not close fully allowing the backward flow of blood. Aortic valve regurgitation places the left ventricle under strain as it has to accommodate abnormally high volumes of blood. It results in enlargement of the heart and heart failure. Shortness of breath on exertion is the commonest symptom. Conditions associated with regurgitation of the aortic valve include bicuspid aortic valve, degeneration of the cusps, enlargement of the aorta, Marfan’s syndrome and infections (endocarditis).
 
Treatment for aortic valve disease

A large body of research work has been carried out aiming to answer the question of when and how to replace the aortic valve. In general, the aortic valve needs replacement when the stenosis or regurgitation cause symptoms or enlargement of the heart. Recent evidence which suggests that the Aortic Valve should be replaced when it has stenosis even without symptoms.

The commonest technique of aortic valve replacement involves complete opening of the chest bone (sternum), connecting the patient with cardiopulmonary bypass, stopping the heart before the valve is removed and a new artificial valve is placed.

Risks 

Like any major surgery, valve replacement carries risk.  Risk varies depending on the fitness of the individual and the function of the heart. Generally if left untreated, the risk of heart failure and death is significantly higher than the risk of surgery to repair the defect.

 There are currently several artificial (prosthetic) aortic valves available – these are discussed and usually decided in conjunction with the patient before surgery. Prosthetic valves can be divided into two types: Tissue or mechanical
 
Tissue aortic valves

Tissue prosthetic aortic valves are made of animal tissue that is mounted within an artificial frame. These valves have an average durability between ten and fifteen years following which they often need re-intervention. Modern tissue valves are likely to last longer that the ones used in the past. The main advantage of tissue valves is that they do not require blood thinning medication (anti-coagulants such as warfarin).
 
Mechanical aortic valves

These are made of totally artificial material such as pyrolytic carbon and titanium. They last for a very long time but can cause formation of clots inside the aorta. They do, therefore, require thinning of the blood (anti-coagulation) through warfarin.
 
Trans-catheter Aortic Valve Implantation (TAVI)

TAVI is performed by a specialist cardiologist mostly to treat aortic stenosis.  A TAVI is the insertion of a prosthetic tissue valve through a puncture in an artery (most commonly the femoral artery). The valve is then advanced and deployed within the stenotic native aortic valve. TAVI has revolutionised the treatment of aortic valve stenosis in patients who are over the age of 75 or who are regarded are high risk for open surgery. It is not widely used in young patient as there is uncertainty concerning its durability.
 
Sutureless Aortic Valves

These are tissue prosthetic valves that are inserted surgically and do not require the use of sutures. Their advantages include rapid deployment, and larger size. Sutureless valves allow a quicker operation in complicated procedures and facilitate minimally invasive aortic valve surgery.
 
Minimal Access Surgery

This allows replacement of the aortic valve through a smaller incision through the upper one third of the sternum in a suitable cohort of patients. It is often associated with less pain, improved respiration and quicker recovery after surgery.
 
References for further reading:

Detailed information on the topic of aortic valve disease and treatment is included in the ‘2025 ESC/EACTS Guidelines for the management of valvular heart disease’. This document is available at https://academic.oup.com/eurheartj/article/46/44/4635/8234488