Heart Valve Replacement

Heart valve diseases, which are commonly observed in Turkey and nearby territories, have been threatening the quality of life of more individuals as a consequence of changing living conditions. Heart valve diseases may be life-threatening unless protective measures are taken. Successful results can be achieved with correct diagnosis and treatment in the early stage. Repair or total replacement of the heart valves due to heart valve diseases are called heart valve replacement surgeries. Heart valve diseases cause increased cardiac load, placing greater stress on the heart muscle and impairing heart functions. In such circumstances, replacement or repair of the heart valve is performed.

For which diseases is a heart valve replacement surgery performed?

Stenosis or regurgitation detected in one or multiple heart valves: The valve is repaired (plasty) or changed (replacement) for treatment. The heart is basically a pump composed of strong muscles, circulating 5-7 liters of blood around the body. This means pumping of 7500 liters of blood daily on average. Heart valves are structures that maintain the unidirectional flow of blood in the system. There are four valves between chambers of the heart, which are: Aortic, mitral, tricuspid and pulmonary valves. Narrowing of a valve prevents the valve from opening fully, which reduces or blocks blood flow from the heart. Valve regurgitation, on the other hand, places a strain on the heart as some blood spurts backward with each contraction. Both disorders place a stain on the heart muscle, resulting in the stretching and enlargement of chambers of the heart. Without intervention, the heart will lose normal functions which will ultimately lead to cardiac failure. The disease is most commonly observed in mitral and aortic valves.

Generally, surgical intervention may be required due to two types of disease in the heart valves.

• Stenosis: Narrowing of the valve
• Regurgitation: A condition in which the valve does not close tightly

Heart valve surgeries are performed by a cardiovascular surgeon. A heart valve surgery requires the surgeon to divide the sternum and dissect the heart in order to gain access to diseased area. The procedure requires connection of the heart to a heart-lung machine which completely takes over the function of heart and lungs, permitting the surgeon to temporarily stop the heart. During the procedure, the surgeon may replace the diseased valve with an artificial valve - which is referred to as valve replacement - and particularly repair mitral and tricuspid valves, or in other words, perform plasty. The most common cause of valve diseases in old-age individuals is the thickening and stiffening of heart leaflets, eventually resulting in inability of the valve to fully open.

How is heart valve replacement or repair performed?

The heart can carry out its pumping function normally only if the valves are able to open fully and they allow forward blood flow and prevent backward flow by closing tightly. Any back flow of blood or blockage which may be caused by the valves will place a strain on the heart. Heart valves, each representing a unique component of the heart, may sometimes fail to perform their mechanical function. In such case, the problem with heart valves is solved by surgical treatment. Mostly the valves between atrium and ventricle need surgical repair, which gives satisfactory results. The valve between the right atrium and ventricle is called the “Tricuspid Valve”, and the one on the left side is called the “Mitral Valve”. Heart valve diseases most commonly treated by a heart valve replacement surgery. The surgical procedure involves removal and repair of the diseased valve, and its replacement by a mechanical or biological valve.

Yet, surgery cannot repair all valves of the heart. In case of valve diseases which result from rheumatic diseases, chances of repair are low due to thickening and calcification which result from increased connective tissue in the valve. Additionally, valve regurgitations resulting from widening of the annulus, or prolapse of a part of the valve, etc. can be successfully repaired by surgical procedure. Mitral valve regurgitation may occur as a result of a heart attack. Valve functions may be impaired due to a number of conditions such as ruptured mitral chordae or weakening, or in other words, aneurysm of the heart wall on which they are attached, after heart attack or endocarditis. In such conditions, a valve repair is required in addition to coronary bypass surgery.

Valve repair procedures target an estimated durability of 10 years and over. The “Transesophageal Echocardiography” device, which is placed into the esophagus during and after the surgery, enables detailed examination of the structure and functions of the heart valves. The experience of anesthesiologists and cardiologists performing the echocardiographic study plays as much a great role as that of the surgeon and the surgical team in the procedure. Their experience make it possible to verify the success of the surgery even before the surgery is completed.

Artificial heart valves have several disadvantages as compared to the natural valves of the heart. Mechanical heart valves require administration of anticoagulants that help prevent blood clots. Without anticoagulants, blood clots may occur on the valve, and block blood vessels, eventually damaging circulation of organs. For example, an impaired circulation in the brain may lead to a stroke. Bioprosthetic valves, known as tissue valves, require a very short-term use of medication (for 3- 6 months). The drawback of this type of valves is the risk of exposure to stiffening and degeneration within a period of 10 years.

Another disadvantage of replacement of a mitral or tricuspid valve by a prosthetic valve is that it requires dissection of the muscles and fibers attaching the valves to the base of heart. Dissection of these muscles will affect the cardiac performance as they facilitate opening and closing function of the heart valve and play a role in contraction of the heart. Therefore, the repair option should be primarily considered instead of replacement if repair of the heart valve is possible and the valve can provide the physiological conditions for a long period.

A certain amount of time is needed to make sure that stitches in the intracardiac area after valve repair and a ring-shaped prosthesis, which is often placed to support the repair, are covered by tissue. This requires a period of 3 to 6 months. During that period, anticoagulants are administered to prevent blood clots on the prosthesis and stitches. To assess the effect of this medication, blood tests will be performed as often as required by the cardiologist and at least once a month. INR home testing devices that have lately become widespread have significantly helped regulating the use of anticoagulants. Following this period, yearly follow-up and echocardiogram by a cardiologist will be sufficient.

FREQUENTLY ASKED QUESTIONS

What is a heart valve?

The heart beats 100,000 times per day, pumping blood through its chambers and valves that perform opening and closing functions in those chambers. There are 4 chambers in the heart, two of which are small and the other two are large. “How many valves are there in the heart?” . The small chambers in the heart are each called “atrium” and the large chambers are called “ventricle”. The left side of the heart receives oxygenated blood, while the right side of the heart receives deoxygenated blood. The valve between the small and large chambers in the left side of the heart is called the “mitral valve”, while the valve pumped out of the large chamber into the entire body is called the “aortic valve”. The valve between the small and large chambers in the right side is called the “tricuspid valve”, and the valve through which the blood is pumped out of the large chamber into the lungs for oxygenation is called the “pulmonary valve”.

What are the symptoms of heart valve diseases?

The heart valve diseases commonly known as thickening of the heart valve, calcification of the heart valve, heart valve prolapse, leaky heart valve, loose heart valve, narrowing of the heart valve and stiffening of the heart valve, is manifested by exercise induced sudden fatigue and shortness of breath. In later stages, the mentioned symptoms may also appear at rest. In asymptomatic patients, the disease may be detected on auscultation of a heart murmur in a routine cardiac examination. Definitive diagnosis of heart valve diseases is made by an echocardiogram and catheter angiography.

What are the causes of heart valve diseases?

Some patients may have congenital anomaly in their heart valves. Such patients may have aortic stenosis or regurgitation due to heart valve disorders which will later develop in time. These patients have risk of valve infection. Also, diseases may be observed in heart valves due to rheumatic fever, mitral valve prolapse, heart valve calcification and heart infections.

What are recommendations for prevention of recurring diseases or different problems in patients who previously underwent heart valve surgery?

Following a heart valve surgery, patients are recommended to avoid getting infection, take prophylactic measures such as getting flu vaccines, pneumonia vaccines, etc., visit their doctor in case of any infection and receive prophylactic antibiotic treatment. Patients often need to know if their condition will deteriorate after the surgery. The patient’s quality of life will be improved after the surgery.

What are the complications after a heart valve surgery? What are advices for patients after a heart valve surgery?

Heart valve diseases can be treated by valve repair or replacement surgery. A majority of cases require valve replacement procedure, which, however, requires lifetime use of medication. Following successfully performed heart valve replacement surgeries, patients are required to follow certain rules for their lifetime. In addition to regular administration of anticoagulants, patients are also expected to stick to their diet. The daily dose of anticoagulants is not fixed but it varies depending on the patient. A patient may be prescribed a quarter dose while another patient has to take 1-2 tablets daily. It is important to use the medication in the dosage prescribed by the physician according to the INR level in blood.

What are advices for patients when using anticoagulants?

Following a heart valve surgery, calculating the correct dosage of the anticoagulant alone is not the only measure which must be taken. This is because there may be an interaction between anticoagulants and foods or drinks. Certain foods may reduce or increase efficiency of the medication. Therefore, patients are required to organize their diet accordingly before starting to administer an anticoagulant. Patients are expected to stick to their diet for their lifetime as prescribed by their doctor under supervision of their dietician.

Is there a death risk in a mitral valve surgery?

There is no such thing as the best mitral valve surgery or best artificial valve. Every surgery and artificial valve has advantages and disadvantages. What is important is to select the most suitable surgery and valve for the patient. Patients should be provided with customized treatment. The most suitable treatment options should be selected by considering the patient’s general condition, mitral valve problem, heart rhythm problems, condition of heart vessels and other diseases, if any. Accordingly, the risks of a surgery can also be identified.

What is thickening of heart valve?

The disorder known as thickening of the heart valve is actually the thickening of the heart muscle. The heart muscle is thickened in case of an increase in the muscle mass or accumulation of different tissues within the muscle. The major cause of this problem is hypertension. Thickening of the heart muscle manifests itself with symptoms such as arrhythmia, palpitation, and late symptoms such as swelling of the feet, and sudden fatigue. Patients with hypertension and problems with their heart valves are the high-risk groups for this disease.

What is a heart valve prolapse?

Heart valve prolapse is a congenital problem. Heart valves perform opening and closing functions. Prolapse of the mitral valve is the situation in which one or two leaflets of the valve camber, extend above or prolapse on the plane of the left atrium during contraction of the heart.

How do heart valves function?

The heart, consisting of four chambers separated by muscles, must always pump blood forward, without allowing a backflow. This forward movement is ensured by heart valves.

What is a leaky heart valve / leaflet? What are the symptoms?

Briefly, a heart valve disease is characterized by the following disorders: In the first type of disease, valve opening function is restricted. The valve is unable to open, causing a narrowing which prevents most of blood from moving forward. This leads to symptoms such as shortness of breath, edema and swelling of the feet. In case of narrowing of a heart valve, signs appear in the early stage due to the mechanism of the problem. The second type of valve diseases is caused by a problem not with the opening but closing function of the valve. The basic function of the valves is to always ensure forward movement of blood. The dysfunction is caused by inability of the valves to close tightly, resulting in a leaky leaflet.

Does a leaky heart valve cause heart failure?

In medical terms, there is no such thing as mild leakage in the heart valve. If there is a high amount of leakage, tissues will not receive adequate amount of blood and the blood pressure will tend to decrease. The blood unable to move forward will accumulate in the heart cavities; but this time, the heart muscles will be stretched and enlarged by an increase in volume, not in pressure, and this will gradually damage the heart’s ability to pump and contract and relax. This is the development process of heart failures due to heart valve diseases.

What are the symptoms of a leaky heart valve?

Leaky heart valves do not cause significant symptoms for a long time especially when they have a slow progress. When serious symptoms are observed, the disorder in the heart might be at an irreversible stage. Therefore, leaky heart valves are more tolerable than narrowing of the valves, but with an insidious progress.

What are the risks of a heart valve surgery?

Like in any other surgical procedure, heart valve surgeries may also have some risks. The cardiovascular surgeon will inform the patient about possible risks of a heart valve replacement surgery. Yet, the risk expected in this type of surgeries is around 1 percent in our country.

What is an inflammation of the heart valves?

Endocarditis is the medical term which refers to an inflammation of the valves of the heart. ‏The immune system of a healthy body is able to kill the bacteria entering the body; however, the bacteria can lodge on heart valves in individuals with a heart valve disease. This causes a serious infection of the heart valve, which is medically known as “infective endocarditis”. This infection is highly resistant to antibiotics. It is characterized by symptoms such as fever of unknown origin and septicemia. Endocarditis may remain undiagnosed as patients usually refer to the hospital with totally different complaints.

What is an enlarged heart valve?

The four chambers of the heart may be individually or collectively enlarged, the cardiac muscle may become enlarged or a buildup of excess fluid may occur in the pericardium. As a result, the heart becomes enlarged.

Is it possible that flaps of the heart valve are floppy?

Yes. Yet, this condition is known as mitral valve prolapse. In fact, mitral valve prolapse (MVP) (also known as floppy valve syndrome) does not threaten human life but restricts the quality of life due to emerging symptoms; it affects 2-5% of the population. In addition to complaints such as chest pain, heart palpitations and shortness of breath, the disease may cause fears of having a heart attack or even cardiophobia due to accompanying panic attack.

What is "backward leakage of blood” at the heart valve?

Certain disorders of the heart valves may lead to backward leakage of some blood after closing of the heart valve. Although this condition is commonly known as the backward leakage of blood at the heart valve, it is medically defined as coronary failure.

Is there a closed surgery option for heart valves?

Mitral valve regurgitation can be repaired without surgery. This method is called Mitraclip. Mitraclip is a minimally invasive treatment method applied for a leaking mitral valve. Leaking mitral valves can be conventionally treated by open heart surgery.

Is there an option for a robot-assisted heart valve surgery?

Robot-assisted treatment is possible, yet in form of open heart surgery. The use of robotic technology involves sternal incisions. The Mitraclip procedure, on the other hand, is totally based on angiography. The procedure involves no thoracic incision; it is performed through a small incision in the groin. The standard method of treatment is the repair of mitral valve. This method is applied by heart surgery. Currently, Mitraclip is a partly experimental method. Mitraclip is the name of the device. The device is similar to a small clip. The mitral valve consists of an anterior and posterior leaflet. Angiography method is applied by advancing a catheter through the femoral vein into the vena cava inferior to gain access to the heart.

Is Transcatheter aortic valve implantation (TAVI) an option for heart valve surgery?

Recently, TAVI has been feasible for aortic valve surgeries. Patients with aortic valve diseases, particularly including old age individuals with chronic cardiac disease in addition to heart disease, and ineligible general health condition for general anesthesia and surgery, can receive treatment with TAVI (Transcatheter Aortic Valve Implantation), which id an interventional method. This is a closed surgery method.

What are the eligibility criteria for MITRACLIP (Non-Surgical Mitral Valve Repair)?

As the procedure has a lower risk for patients whose health condition is ineligible for open heart surgery, Mitraclip is used from time to time in old-age high risk patients with concomitant diseases. However, open surgery for repair of the valve has still been the standard treatment method. This procedure is performed by cardiovascular surgeon, while Mitraclip procedure is performed by interventional cardiologists.

What are advices for patients after a heart valve surgery?

Patients are recommended to avoid getting infection, take prophylactic measures such as getting flu vaccines, pneumonia vaccines, etc., visit their doctor in case of any infection and receive prophylactic antibiotic treatment. Patients often need to know if their condition will deteriorate after the surgery. The patient’s quality of life will be improved after the surgery.

 

Prepared by Memorial Medical Editorial Board.