Heart valve surgery: repair and replacement

What is it?
Heart valve surgery or other procedures are performed to repair or replace a valve in the heart that is not working properly.

Why is it performed?
There are four valves in the heart:

• Tricuspid
• Pulmonary
• Mitral
• Aortic

Valves control the flow of blood by making it move in one direction through the different chambers or parts of the heart. If a valve is not working correctly, blood flow is impaired. (See Anatomy of the heart.) For example, if a valve does not close properly, blood may leak between the chambers or flow backwards, a condition known as valve regurgitation, insufficiency, or incompetence. If a valve is narrowed (also called stenosed), blood flow through the heart may be restricted.

If the valve problem is minor, it may be treated with medication. But if the heart valve damage is severe, a procedure may be required to repair or replace the malfunctioning valve.

Valve repair or replacement may be required if a valve has been damaged by:

• Infection (endocarditis).
• Rheumatic heart disease.
• Congenital heart defect.
• Mitral and/or aortic valve disease.
• Normal aging and wear.

What is done?
There are a number of procedures for repairing or replacing valves. Surgery is commonly required, although there are some newer, non-surgical procedures.

Valve Repair

Surgical

• A commissurotomy is surgery to open up valves that have thickened and are perhaps stuck together. The valve is opened by cutting the points where the leaflets of the valve meet. Commissurotomy is a type of valvuloplasty or valve re-shaping.
  
• Annuloplasty is a technique to repair an enlarged annulus, a ring of fibrous tissue at the base of the heart valve. To repair the annulus, sutures are sewn around the ring to make the opening smaller. Alternatively, a ring-like device is attached around the outside of the valve opening. The ring provides support to the valve so it can close more tightly.
  
• A surgeon may reshape a valve by cutting out a section or sections of a leaflet and then sewing the leaflet back together.
  
• Decalcification is surgery to remove calcium buildup from the leaflets.
  
• Valves are supported by cords (called chordae tendineae) and papillary muscles. If these are stretched or weak, the valve may not close properly. By replacing or shortening the cords, the valve will be strengthened and able to close properly.
  
• If there are holes or tears in the leaflets of the valve, a surgeon may repair them with a tissue patch.

Minimally Invasive Valve Repair

Unlike conventional surgery, minimally invasive surgery does not involve sawing through the breastbone and opening the chest. The surgeon watches the heart on a video screen and operates using long-handled surgical tools inserted through small incisions. In some cases, robotic arms are used. Minimally invasive valve repair is only available in some hospitals. It is also referred to as endoscopic or robotic heart surgery.

Non-Surgical Valve Repair

Percutaneous or catheter-based procedures do not include making any incisions in the chest or stopping the heart. Instead, a thin flexible tube called a catheter is inserted into a blood vessel in the groin or the arm and then threaded up into the interior of the heart.

• Percutaneous or balloon valvuloplasty is used in people with stiffened or narrowed (stenosed) pulmonary, mitral or aortic valves (more commonly for the mitral than the aortic valve). A balloon tip on the end of the catheter is positioned in the narrowed valve and inflated to enlarge the opening or to crack open calcified tissue.
  
• Several different methods of percutaneous mitral valve repair are being developed. In one, the catheter tip is used to push the valve back into shape. In another, a small clip-like device is put into place to strengthen the valve leaflets. These procedures are still in the developmental phase and are available in a limited number of centres.

Valve Replacement

Replacement is more commonly used to treat aortic valves or severely damaged mitral valves. There are two kinds of valves that are used for valve replacement and you should talk with your doctor about which type is best for you.

• Mechanical valves are made from durable metals, carbon, ceramics and plastics. A fabric sewing ring is used to attach the valve to the tissues in the patient’s heart. The major advantage is durability. However, blood thinners must be taken the rest of the patient’s life to prevent blood clots. The valve makes a soft clicking sound when it floats shut, which may bother some patients. People generally adjust quickly to this sound.
  
• Biological valves are made from:
  • Animal tissue, either an actual pig valve or a bovine pericardial engineered valve (a xenograph).
  • Human tissue of a donated heart (an allograft or homograft), used most often to replace infected valves.
  • A patient’s own tissues (an autograft). A Ross Procedure (also called a Switch Procedure) involves taking the patient’s normally functioning pulmonary valve and using it to replace a diseased aortic valve. The pulmonary valve is then replaced with a donated (homograft) pulmonary valve.

Biological valves are not as durable as mechanical valves and may need to be replaced between 5 and 15 years. Patients with biological valves will need to take blood thinners in the short term.

Minimally Invasive Valve Replacement Surgery

In minimally invasive valve surgery, long-handled tools are inserted into the chest through four or more small incisions. While watching a video monitor, the surgeon manipulates the tools and conducts the surgery. In some cases, robotic arms may be used to manipulate the tools for the surgeon. Only some hospitals can offer minimally invasive valve surgery. This type of surgery is sometimes referred to as endoscopic or robotic heart surgery.

Non-Surgical Valve Replacement

Percutaneous valve replacement is a non-surgical approach to valve replacement that uses long, flexible tubes called catheters. Instead of opening the chest to operate on the heart, a catheter is inserted into an artery (usually in the groin or arm) and threaded through the blood vessels into the heart. Percutaneous valve replacement does not require stopping the heart or the use of a heart-lung machine.

What you can expect
Usually, valve surgery is scheduled ahead of time. Approximately a week before your surgery, you may be asked to visit your hospital’s preadmission unit. Blood and urine tests, an electrocardiogram, and an X-ray may be performed in preparation for your surgery. Your doctor will explain the risks and benefits of the procedure and you will be asked to sign a consent form. Please inform your doctor if you:

• Have ever had a reaction to any contrast dye, iodine, or any serious allergic reaction (for example, from a bee sting or from eating shellfish).
• Have asthma.
• Are allergic to any medication.
• Have any bleeding problems or are taking blood-thinning medication.
• Have a history of kidney problems or diabetes.
• Have body piercings on your chest or abdomen.
• Have had any recent change in your health.
• Are, or may be, pregnant.

Most patients are admitted to the hospital the day before their procedure. The night before, you will be asked to bathe to cleanse or disinfect your skin. At the hospital, the area to be operated on will be washed, scrubbed with an antiseptic cleanser and if necessary, the hair on your chest will be clipped.

Valve surgery is conducted under a general anesthetic so you will be asleep throughout the procedure. To reduce the risk of vomiting while asleep, you will be asked not to eat or drink after midnight the night before surgery. If you smoke, you should stop at least 2 weeks before your surgery, as smoking can contribute to blood clotting and breathing problems.

The heart must be stopped so the surgeons can work on the valve or valves. To ensure your body continues to receive a flow of oxygen-rich blood, you will be hooked up to a heart-lung machine. This machine takes over the pumping action of the heart.

The surgery can take anywhere from 2 to 4 hours, depending upon the number of valves that need to be repaired or replaced. When you wake up, you will be in the recovery room or an intensive care unit (ICU). You can expect to stay in the hospital for about a week. How quickly you recover from surgery will depend in large part upon how healthy you were before the surgery.

If you have minimally invasive surgery, your hospital stay will probably be shorter and your recovery quicker.

When you return home, keep an eye on your incisions. Some bruising is normal, but contact your doctor if you experience increased pain, redness, swelling, bleeding or other draining from an incision, fever, chills or generally feeling unwell.

Last reviewed March 2007.