What Is Aortic Valve Surgery?

What is an aortic valve and what is its role?

Aorta is the largest blood vessel in the human body which carries oxygenated blood from the left ventricle of the heart to the rest of the body. Aortic valve is located between the left ventricle of the heart and the aorta.  The main function of this valve is to regulate flow of blood from the heart to the aorta.

Body organs and tissues need continuous and adequate supply of oxygenated blood for proper functioning. During contraction of the heart aortic valve opens and oxygenated blood from the heart is pumped into the aorta. During relaxation of the heart this valve is closed so blood does not flow back from the aorta into the heart. If the aortic valve is not closed properly then the blood ejected into the aorta lacks force which results in drop in blood pressure and decreased blood supply to the body.  It also causes the heart to work harder which may result in conditions like left ventricular hypertrophy. If left untreated this can seriously impact normal cardiovascular functioning and result in serious complications like heart failure.

What are the types of aortic valve disorders?

Aortic stenosis

When the aortic valve narrows it is called aortic stenosis. This happens mostly due to thickening or calcification of valve leaflets. It restricts flow of blood from the left ventricle to the aorta and patient experiences chest pain, shortness of breath, fatigue, dizziness, and fatigue due to reduced blood supply.¹

Aortic regurgitation (aortic insufficiency)

When the aortic valve does not close properly it results in blood flowing back into the left ventricle this is called aortic regurgitation or aortic insufficiency.² This insufficiency results in chest pain, dizziness, shortness of breath.

Bicuspid aortic valve

Normally the aortic valve has three leaflets (tricuspid) but in some people this valve has only two leaflets (bicuspid) so the valve is unable to function properly and results in aortic stenosis or aortic regurgitation over the time.³

Aortic valve prolapse

In prolapse the valve leaflets prolapse or bulge back into the left ventricle during heart's contraction resulting in aortic regurgitation.⁴  

Aortic valve endocarditis

Endocarditis is an inflammation of the inner lining of the heart and the heart valves. This leads to dysfunction of the valve due to the damage it causes. Patients may experience fever, weight loss fatigue along with other valve dysfunction symptoms.

Rheumatic aortic valve disease

If the inflammation of the valve associated with rheumatic fever caused by streptococcal infection it is called rheumatic aortic valve disease.⁵

When is surgery needed?

1. Stenosis or narrowing of the valve especially when it is associated with regurgitation. Aortic stenosis patients shows clear improvement after aortic valve replacement as per this research report.⁶
2. In aortic regurgitation in which there is backflow of blood into the left ventricle, aortic valve surgery is helpful.⁷
3. Prolapse of the valve
4. Perforation in the valve
5. Congenital abnormality like bicuspid valve where the aortic valve has two leaflets instead of the normal three.
6. In young patients often repair is preferred over replacement to avoid lifelong dependency on anticoagulants. 

What surgical approaches are in practice?

Open heart surgery

In open heart surgery, the chest is opened by cutting through the breastbone. The patient is connected to a heart lung machine which takes over functions of heart and lungs. The surgeon stops the heart, and the repair or replacement of the valve is done. This kind of approach has larger incision, more risks and longer recovery time.

Transcatheter aortic valve replacement (TAVR)

In this approach smaller incisions are taken, and a catheter is used to deliver the valve to its location in the heart.⁸ This surgery has lower risks and quicker recovery times. TAVR is a relatively new procedure and mostly recommended for elderly patients or those who are at higher risk of surgery. More research is needed to compare its effectiveness over standard valve replacement procedures.

What surgical techniques are used?

Aortic valve repair

In aortic valve repair surgery patients' own valve is preserved and reconstructed surgically rather than replacedwith a new artificial one. Below are few of the techniques used for valve repair surgery.

Valvuloplasty

In this technique valve leaflets are reshaped or reconstructed to resolve the issue. For example, in commissurotomy fused valve leaflets are seperated.

Plication of valve leaflets

Sometimes excess tissue on valve leaflets causes prolapse of the valve so in plication technique this excess tissue is removed.

Resection of valve tissue

If there is leaflet perforation or localized valve disease then resection means a portion of the valve leaflets is removed to eliminate the defects.

Annuloplasty

Aortic valve annulus is a ring-like structure which supports the valve leaflets. This ring is replaced to improve valve closure and reduce back flow of blood in annuloplasty.

Cusp extension or augmentation

If additional tissue is added to the valve leaflets to increase their size it is called cusp extension.

Aortic root reconstruction

If there is dilation of the aortic root then aortic root reconstruction is performed which stabilizes aortic root and improves valve function.

Patch repair

If there is perforation or tear in the valve leaflets patch repair can be done. For the patch either the patient's own tissue or synthetic material is used.

Aortic valve replacement

Not all cases can be treated by repair of the existing valve sometimes valve replacement remains the ideal option. Below are the types of valves used in this procedure.

Mechanical valve replacement

Mechanical valves are made from man-made or artificial material like titanium or pyrolytic carbon. They are durable and resistant to wear and tear, but the patients need to take lifelong anticoagulant medications to prevent blood clot formation. They may produce an audible click.

Bioprosthetic valve replacement

Bioprosthetic valves are made from animal tissues, mostly pig or cow. They may need to be replaced after 10-15 years because tissues can degenerate over time.There is no need for anticoagulants (blood thinning medications) because they carry lower risk of blood clot formation. 

Potential complications and management

Most patients have a successful outcome however complications may still occur.

Bleeding

Just like with any other surgery bleeding is a common concern with aortic valve surgery. If excessive bleeding occurs, blood transfusion or additional surgery might be needed.

Infection

Infection can occur at the heart valve or at the incision site, for which antibiotics are typically administered before and after surgery to reduce the risk.

Blood clots

Risk of blood clot formation is increased after aortic valve surgery. This can result in stroke or pulmonary embolism, to avoid this blood thinning medications are prescribed.

Heart rhythm disturbances (Arrhythmias)

Normal electrical impulses of the heart can get disrupted due to the surgery which causes a condition called arrhythmia or heart rhythm disturbance. In such cases temporary or permanent placements of pacemakers is advised.

Stroke

If any blood clots or debris gets dislodged during surgery and travels to the brain, it disrupts the blood supply to the brain causing stroke.

Heart attack

Additional stress on the heart during surgery can cause a heart attack if there are any other coexisting coronary artery diseases.

Prosthetic valve complications

Those who receive a prosthetic valve there is a risk of complications specific to the type of valve.

Pulmonary complications

If a patient has any preexisting lung conditions, it can lead to complications like pneumonia or other respiratory conditions.

Kidney problems

Some people may experience kidney function abnormalities if there is prolonged blood pressure reduction during the procedure.

Prognosis and outcome after surgery

As stated in a research report “nearly 80% of patients undergoing surgery for valve replacement have outcomes that are superior to those by the predicted risk models.”⁹

Regular follow up with tests like ECG at regular intervals is required for monitoring after surgery. The long-term outcome of the surgery depends on the seriousness of the underlying condition, patients age and health.

Balanced diet, regular exercise, stress management, avoiding smoking and alcohol also helps to improve the quality of life and outcome after surgery.

Summary of aortic valve surgery

Aortic valve is located between the left ventricle of the heart and the aorta.  It is one of the four valves present in the heart. The main function of the aortic valve is to regulate flow of blood from the left ventricle of the heart to the aorta. If there are any abnormalities in the structure and function of the aortic valve it causes symptoms like chest pain, dizziness, fatigue, and shortness of breath. If this is not investigated and treated on time it can lead to serious complications like heart failure.  

In aortic valve repair surgery patient's own valve is preserved and reconstructed surgically, if it cannot be treated with valve repair, then replacement of the valve with a natural origin (bioprosthetic) or synthetic material (mechanical) valve is considered.

The surgery can be done either by traditional open-heart surgery or the newer TAVR techniques. In TAVR smaller incisions are taken, and a catheter is used to deliver the valve to its location in the heart. Natural-origin valves might need replacing after a few years. Synthetic valves are more durable, but patients need to be on blood-thinning medications for a lifetime.

With advancements in surgery, risks are reduced, and most patients have a successful outcome with aortic valve surgery. Patients report improved quality of life and relief from symptoms after the surgery. A balanced diet, regular exercise, stress management, and avoiding smoking and alcohol also help to improve the quality of life and outcome after surgery.