Heart Valve Surgery

Overview

Heart valve surgery is a solution for heart valve disease. Heart valve disease occurs when at least one of the four heart valves fails to function correctly. Heart valves keep blood flowing through the heart in the right way.

The mitral valve, tricuspid valve, pulmonary valve, and aortic valve are the four heart valves. Each valve has flaps, which are called leaflets for the mitral and tricuspid valves and cusps for the aortic and pulmonary valves, respectively. During each heartbeat, these flaps should open and close once. Blood flow via the heart to the body is interrupted when valves do not open or close appropriately.

In a healthy heart, valves direct the flow of blood in one direction through the heart and the body. If a valve fails to function properly, blood flow and the delicate network of blood arteries that transport oxygen throughout the body are disrupted.

If your valve problem is modest, your doctor may keep an eye on your symptoms or prescribe medication. If your problem is more severe, surgery to repair or replace the valve is typically necessary to prevent long-term damage to your heart valve and heart.

A surgeon performs heart valve surgery to repair or replace a damaged or diseased heart valve or valves. Many surgical procedures, including open-heart surgery and minimally invasive cardiac surgery, can be utilized to repair or replace heart valves.

The type of heart valve surgery required is determined by a number of variables, including your age, health, and the type and degree of heart valve disease.

Epidemiology of Heart Valve Surgery

All cardiac valve procedures had a mean yearly incidence of 4.75 per 100,000 people. The yearly mean incidence of RHD, degenerative valvular disease, and unrelated endocarditis was 2.86, 0.73, and 0.21 instances per 100,000 populations, respectively.

During the four-year study period, no temporal changes in the overall or etiology-specific yearly incidence of cardiac valve surgery were identified. Overall, the average yearly incidence of heart valve surgery was related to age.

Indications for Heart Valve Surgery

Aortic valve repair or replacement:

Aortic valve replacement is used to treat aortic stenosis in order to avoid angina, syncope, or congestive heart failure. Individuals with severe aortic stenosis are candidates for aortic valve replacement when symptoms emerge or their heart function is compromised. 

Some persons with asymptomatic aortic stenosis may potentially be candidates for aortic valve replacement, particularly if symptoms emerge during activity testing. If echocardiography reveals substantial heart abnormalities, patients with mild aortic valve stenosis who require another form of cardiac surgery (e.g., coronary artery bypass surgery) should also have their valve treated by the surgical team.

The combination of low gradient aortic stenosis and associated left ventricular failure raises substantial concerns for both the anesthesiologist and the patient. Stress echocardiography (using dobutamine infusion) can assist evaluate whether the ventricle is dysfunctional due to aortic stenosis or because the myocardium has lost its capacity to contract.

Many persons with aortic insufficiency do not experience symptoms until they have had the condition for a long time. Aortic valve replacement is recommended for symptoms such as shortness of breath and when the heart has begun to grow (dilate) as a result of pumping the increasing amount of blood that leaks back through the valve.

Mitral valve replacement/repair:

Mitral valve surgery is recommended for severe valvular dysfunction that is generally symptomatic, while surgery is also recommended in certain silent instances. Valvular disease severity is determined using established echocardiographic criteria. Cardiac magnetic resonance imaging may be useful in specific situations, such as chronic ischemic mitral regurgitation, when myocardial perfusion and viability must also be assessed.

The most common indication for mitral valve surgery is symptomatic chronic severe primary mitral regurgitation, usually owing to degenerative valve disease, with a left ventricular ejection fraction (LVEF) of >30%; mitral valve surgery is indicated in symptomatic patients with severe LV systolic dysfunction (LVEF <30%, and/or left ventricular end-systolic diameter [LVESD] >55 mm) refractory to medical therapy when there is low comorbidity, preferably mitral valve repair although mitral valve replacement may be considered in these patients when the likelihood of successful repair is low.

A randomised controlled clinical study has not been performed to explore the role of surgery against active monitoring for asymptomatic severe primary mitral regurgitation with intact LV function and no additional indications for surgery. A recent meta-analysis of the few published propensity-matched studies comparing early surgery with active monitoring discovered that early surgery had better long-term mortality, with no difference in operative mortality or repair rate between early surgery and surgery "triggered" by current criteria.

Immediate severe mitral regurgitation caused by papillary muscle rupture in the setting of inferior (right coronary artery region) or posterior (circumflex artery area) STEMI is poorly tolerated and frequently results in acute pulmonary oedema and cardiogenic shock. After initial stability and evaluation, emergency mitral valve replacement is necessary. Acute severe mitral regurgitation caused by immediate chordal rupture or endocarditis can cause acute pulmonary oedema, however surgery can be postponed for days to weeks with proper heart failure and/or antimicrobial medication.

Tricuspid valve replacement/ repair:

Isolated tricuspid valve repair is uncommon in spite of the fact that tricuspid valve abnormalities can result in significant morbidity and mortality. Most of the tricuspid valve procedures are performed secondarily with other primary cardiac surgical procedures. The current most common indication is to perform tricuspid valve surgery in patients who have symptomatic severe primary tricuspid regurgitation. Following are the indications for tricuspid valve repair or replacement:

• Symptomatic severe tricuspid stenosis.
• Severe tricuspid stenosis without symptoms when the patient is undergoing left-sided valve surgery.
• Symptomatic severe primary or secondary tricuspid regurgitation.
• Severe primary or secondary tricuspid regurgitation (symptomatic or asymptomatic) when the patient is undergoing left-sided valve surgery.
• Moderate to severe primary tricuspid regurgitation when the patient is undergoing left-sided valve surgery.
• Asymptomatic or mildly symptomatic primary tricuspid regurgitation with evidence of progressive right ventricular dilatation and dysfunction.
• Mild or moderate progressive functional (secondary) tricuspid regurgitation with a dilated annulus (more than 40 mm or more than 21 mm/m2) when the patient is undergoing left-sided valve surgery.
• Tricuspid valve endocarditis.
• Carcinoid involvement of the tricuspid valve. 
• Congenital malformations e.g., Ebstein anomaly.
• Traumatic or iatrogenic injuries to the valve when taking biopsies or from pacemaker leads.

Pulmonary valve replacement/repair:

PVR is now used to treat symptomatic and asymptomatic individuals who are at high risk of right ventricular (RV) dilatation, RV failure, exercise intolerance, arrhythmia, and sudden cardiac death. 

Types of Heart Valve Surgery

Depending on the problem, there are a several different procedures for repairing or replacing valves.

Surgical valve repair:

Surgical procedures are generally used for problems with the mitral or tricuspid valves.

1. Commissurotomy: it is a treatment for a tight valve. The valve flaps (leaflets) are cut to loosen the valve slightly, allowing blood to pass easily.
2. Annuloplasty: it is done for a leaky valve. There is a ring of fibrous tissue at the base of the heart valve called the annulus. To repair an enlarged annulus, sutures are sewn around the ring to make the opening smaller. Or, a ring-like device is attached around the outside of the valve opening to support the valve so it can close more tightly.
3. Valvulotomy: A valvulotomy, valvotomy, valvuloplasty, or valvoplasty is a procedure used in heart valve surgery that consists of making one or more incisions at the edges of the commissure formed between the two (mitral valve), or three tricuspid valve leaflets. This relieves the constriction of valvular stenosis (especially mitral valve stenosis).

Non-surgical valve repair:

1. Percutaneous or catheter-based procedures: they are done without any incisions in the chest or stopping the heart. Instead, a thin flexible tube called a catheter is inserted into a blood vessel in your groin or arm and then threaded through the blood vessels into your heart.
2. Percutaneous or balloon valvuloplasty/valvotomy: it is used for stiffened or narrowed (stenosed) pulmonary, mitral or aortic valves. A balloon tip on the end of the catheter is positioned in the narrowed valve and inflated to enlarge the opening.
3. Percutaneous mitral valve repair methods: such as edge-to-edge repair - can fix a leaky mitral valve in a patient who is considered high risk for surgery. A catheter holding a clip is inserted into the groin and up into the left side of the heart. The open clip is positioned beyond the leaky valve and then pulled back so it catches the flaps (leaflets) of the mitral valve. Once closed, the clip holds the leaflets together and stops the valve from leaking.

Heart valve replacement:

If your heart valve is too badly damaged to be repaired, surgery may be needed to replace it with a new mechanical or biological valve. Age is generally a factor in deciding which type to use – biological valves are generally preferred for older people. You and your doctor will discuss the options and decide which is best for you and your circumstances.

1. Mechanical Heart Valves:

Mechanical heart valves are made from materials such as titanium and carbon. They usually consist of two leaflets and a metal ring surrounded by a ring of knitted fabric, which is sewn onto the heart in place of the original valve. There are several different models available for aortic and mitral replacement surgeries. 

Mechanical valves have the benefit of being extremely durable. These valves, however, create a surface on which blood clots can easily develop. As a result, everyone who has had a mechanical valve implanted must take blood-thinning medication for the rest of their lives, such as warfarin, to avoid the formation of blood clots, which can lead to a heart attack or stroke. These valves should be avoided in women of childbearing age, as warfarin is not recommended for usage during pregnancy, as well as those who are at high risk of falling or bleeding.

Mechanical valves, as opposed to tissue valves, increase a patient's risk of blood clot formation as well as severe bleeding from anti-clotting medication. As a result, for patients who are at high risk of clotting or bleeding, tissue valves are frequently preferable to mechanical valves. Women who want to have children are also included in this category, as warfarin cannot be administered during pregnancy owing to the risk of fetal abnormalities. 

Mechanical valves, on the other hand, are more durable and, as a result, are generally preferred in younger patients who would otherwise require many re-operations to replace a degenerating tissue valve. Aside from these distinctions, there is no discernible difference in long-term survival between these two types of valves.

2. Biological (also called bioprosthetic) or tissue valves:

Tissue valves are made of animal or human tissue and are also known as biological or bioprosthetic valves. The valves are made from porcine (pig), bovine (cow), and equine (horse) tissue and then treated with a preserving solution before being installed on a flexible frame to aid in deployment during surgery.

The bottom of a tissue valve, like mechanical valves, is frequently enclosed with a ring of knitted fabric that is sewed onto the heart. A human tissue valve from a donor human heart, known as an allograft or homograft, may also be utilized as a replacement valve in addition to animal-derived valves. Tissue valves can be utilized in open heart surgery or in transcatheter aortic valve implantation, a minimally invasive aortic procedure (TAVI).

Tissue valves provide several advantages over mechanical valves, including the elimination of the need for lifetime warfarin medication to prevent the formation of blood clots. One downside is that they are less durable than mechanical valves, with many requiring re-operation after 10 to 20 years.

Minimally invasive valve repair and replacement

Minimally invasive surgery, as opposed to traditional surgery, does not entail cutting through the breastbone and opening the chest. It does not necessitate the stopping of your heart or the use of a heart-lung machine. The surgeon operates with long-handled surgical equipment placed through small incisions while watching your heart on a television screen. Robotic arms are employed in various circumstances. Although minimally invasive valve repair and replacement are appropriate for some kinds of valvular heart disease, they are only offered in a few institutions. It is also known as endoscopic or robotic cardiac surgery.

TAVI (transcatheter aortic valve implantation) is also known as transcatheter aortic valve replacement (TAVR). TAVI is a minimally invasive surgical valve replacement technique used to treat symptomatic aortic valve stenosis. It differs from typical valve replacement surgery in two important ways. TAVI is performed through minor incisions in the groin or chest rather than opening up the chest. Instead than mending or replacing the damaged aortic valve, a new one is implanted immediately on top of the damaged one.

Through small incisions in the groin or chest, the surgeon inserts a catheter holding a replacement, collapsible aortic valve. The catheter is directed to the right spot in the heart using ultrasound and chest x-rays, and the new valve is inserted and inflated. When the replacement valve is installed, it instantly begins to regulate blood flow.

Persons who have TAVI tend to recover faster and stay in the hospital for less time (three to five days on average) than people who have open-heart valve surgery. TAVI is often recommended for patients who are at high risk of complications following open-heart surgery. Your healthcare team will evaluate your symptoms and general health to see if TAVI is a good fit for you.

How to prepare yourself for the surgery?

Your doctor and treatment team will go over the details of your heart valve surgery with you and answer any questions you may have. Before being admitted to the hospital for heart valve surgery, discuss your hospital stay with your family and the assistance you will require when you come home.

• Food and medications:

Before you have heart valve surgery, talk to your doctor about:

1. When you can take your regular medications and whether you can take them before your surgery.
2. Allergies or reactions you've had to medications.
3. When you should stop eating or drinking the night before the surgery.

• Clothing and personal items:

If you're having heart valve surgery, your treatment team might recommend that you bring several items to the hospital, including:

1. A list of your medications.
2. Eyeglasses, hearing aids or dentures.
3. Personal care items, such as a brush, a comb, shaving equipment and a toothbrush.
4. Loose, comfortable clothing.
5. A copy of your advance directive.

During heart valve surgery, don't wear:

• Jewelry
• Eyeglasses
• Contact lenses
• Dentures
• Nail polish

You may need to have your body hair shaved where the incisions will be made. A special soap might be used to wash your skin to help prevent infection.

What happens during the procedure?

During the operation, you will be sedated with anesthetics to put you to sleep. During the treatment, you'll be hooked up to a heart-lung bypass machine, which will keep blood flowing through your body. Standard open-heart surgery, which includes piercing your chest through your breastbone, can be used to replace a heart valve. Smaller incisions are utilized in minimally invasive cardiac surgery than in open-heart surgery.

Minimally invasive heart surgery involves surgery with long tools introduced via one or more small incisions in the chest (thoracoscopic surgery), surgery with a small incision in the chest, or surgery conducted by a surgeon with the help of a robot (robot-assisted heart surgery).

Minimally invasive heart surgery might involve a shorter hospital stay, quicker recovery and less pain than you'd have with open-heart surgery. Minimally invasive heart surgery ideally should be performed at medical centers with medical teams experienced in performing these types of procedures.

• Heart valve repair:

Your doctor may often recommend heart valve repair when possible, as it saves the heart valve and may preserve heart function. Heart valve repair surgery may include:

• Patching holes in a valve.
• Reconnecting valve flaps (leaflets or cusps).
• Removing excess valve tissue so that the leaflets or cusps can close tightly.
• Replacing cords that support the valve to repair the structural support.
• Separating valve flaps that have fused.
• Tightening or reinforcing the ring around the valve (annulus).

A long, thin tube (catheter) and clips, plugs, or other devices are used in several heart valve replacement operations.

A catheter treatment known as balloon valvuloplasty may be used to treat a valve with a constricted valve opening. A small, flexible tube (catheter) with a balloon on the tip is inserted into an artery in your arm or groin and guided to the damaged valve by a doctor.

The balloon is inflated, causing the aperture of the heart valve to widen. The balloon is subsequently deflated and the catheter and balloon are removed by the doctors.

• Heart valve replacement:

If your heart valve cannot be repaired and a catheter-based surgery is not an option, it may be necessary to replace the valve. Your doctor will remove the heart valve and replace it with a mechanical valve or a valve manufactured from cow, pig, or human heart tissue (biological tissue valve).

Biological valves frequently need to be changed since they deteriorate over time. If you have a mechanical valve, you will need to take blood-thinning drugs for the remainder of your life to keep blood clots at bay. Doctors will go through the risks and advantages of each kind of valve with you.

Certain heart valves may be replaced using a less invasive catheter surgery. A catheter method, for example, might be used to introduce a replacement valve into a biological replacement valve in the heart that is no longer functioning effectively.

What happens after the surgery?

You'll usually stay a day or more in the intensive care unit following your heart valve surgery (ICU). An IV will be used to provide fluids and drugs to you. Other tubes empty the bladder of urine and the chest of fluid and blood. Oxygen may be administered to you through a mask or nasal prongs in your nose.

After your time in the ICU, you'll most likely be transferred to another hospital room for a few days. The length of your hospital stay is determined on your health and procedure.

After heart valve surgery, your treatment team will monitor your condition and watch for signs of infection at the incision sites. The team will check your blood pressure, breathing and heart rate. The team will also work with you to manage any pain you have after surgery.

You'll likely be asked to walk regularly to gradually increase your activity, and to cough and to do breathing exercises as you recover.

You'll be given instructions to follow during your recovery, such as:

• Watching for signs of infection in your incisions
• Taking your medications
• Properly caring for incisions
• Managing pain and other side effects after your surgery

After heart valve surgery, your doctor will tell you when you can return to activities. You'll need to attend regular follow-up appointments with your doctor. You might have several tests to evaluate and monitor your condition.

Your doctor may recommend making healthy lifestyle changes to keep your heart working well. Examples of heart-healthy lifestyle changes are:

• Eating a healthy diet.
• Getting regular exercise.
• Managing stress.
• Avoiding tobacco use.

Conclusion

Heart valve surgeries and procedures are used to repair or replace a heart valve that isn't working correctly due to valvular heart disease (also called heart valve disease). Heart valve surgery is an open-heart procedure that is performed via the breastbone into the chest. It is a major procedure that can take two hours or more to complete, and recuperation can take several weeks. There are newer, less invasive techniques available for specific forms of valvular heart disease, but these are only available at a few facilities.

Proper evaluation of the patient with valvular heart disease begins with a thorough history and physical examination. Today, sophisticated noninvasive tests(especially echocardiography with color flow Doppler imaging) complement the information gained at cardiac catheterization. Information previously available only through cardiac catheterization can now be obtained from these noninvasive techniques. Serial evaluations can be performed, which are important in managing lesions of borderline hemodynamic significance and in avoiding subclinical deterioration of left ventricular contractility. 

Heart valve surgery is done to treat heart valve disease. There are two basic types of heart valve problems: a narrowing of a valve (stenosis), a leak in a valve that allows blood to flow backward (regurgitation).

Sometimes, doctors recommend heart valve surgery even for those who don't have symptoms. If you need heart surgery for another condition, doctors might perform heart valve repair or replacement at the same time. Together, you and your doctor should discuss whether heart valve surgery is right for you and if minimally invasive heart surgery is an option.