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| SURGERIES OF THE HEART |
Aortic Valve Replacement
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Aortic valve replacement is an open-heart surgery that removes a malfunctioning aortic valve and puts a new one in place. The replacement valve may be:
* Mechanical–Made entirely out of artificial materials
* Bioprosthetic–Engineered out of a combination of artificial materials and tissues from a pig, cow, or other animal
* Homograft or Allograft–Harvested from a donated human heart
* Ross Procedure (Self-donated)–In selected patients less than 50 years of age, another one of the patient’s own heart valves, the pulmonic valve, may be removed from its original location and sewn in to take the place of the faulty aortic valve. A homograft is then sewn in to take the original place of the pulmonic valve.
REASONS FOR THE PROCEDURE
Aortic valve replacement is performed when the aortic valve is not working properly. Sometimes, the aortic valve is misshapen due to a birth defect. This is called Congenital Aortic Valve Disease. Other times, the aortic valves work adequately for years before becoming too stiff or too floppy to open and close fully. This is called Acquired Aortic Valve Disease. This may happen due to normal aging (that leads to calcium build-up on the valves causing them to malfunction) or as a result of other conditions, such as:
* Rheumatic Valve Disease ( Rheumatic Fever) —a complication of streptococcal throat infection, which can damage the valve
* Endocarditis –an infection inside the heart that involves the valves
* Aortic Aneurysms –an abnormal widening or outpouching of the aortic artery
* Aortic Dissection –bleeding into the wall of the artery, usually due to the presence of an aortic aneurysm
* If the valve is too stiff to open fully ( aortic valve stenosis ), the ventricle may have a hard time pumping blood into the aorta. If the valve is too floppy to close fully, there may be a backwash of blood flow from the aorta that leaks back into the ventricle ( aortic valve regurgitation ). Both of these problems may become severe enough to require surgery to replace the faulty aortic valve.
RISK FACTORS FOR COMPLICATIONS DURING THE PROCEDURE
* Other heart conditions
* Lung conditions
* Chronic illness, including high blood pressure and diabetes
* Kidney or liver problems
* Elderly age
* Infections
* Smoking
* Obesity
BEFORE THE PROCEDURE
The following test may be conducted prior to the procedure:
* Physical Exam
* Blood Tests –to make sure that one do not have an infection, to make sure that the blood is clotting properly, and to determine the blood type in case one needs a transfusion during or after surgery
* Echocardiogram –a test that uses sound waves to produce a moving picture of the heart and its valves
* Electrocardiogram –a test of the electrical system of the heart
* Cardiac Catheterization –a test in which a very thin tube is threaded up through the aorta. Dye is squirted through the catheter, and digital images are captured. These images can reveal problems with the functioning of the aortic valve and also determine whether the heart arteries are unobstructed and free from disease.
In the days just before the procedure:
* Regular medications should be reviewed with the surgeon; one may need to stop taking certain drugs
* Do not eat or drink anything after midnight the night before the surgery, unless told otherwise by the doctor
* Arrange for help at home after returning from the hospital
* Arrange to have someone drive the patient home when leaving the hospital
* Wear comfortable clothing
PROCEDURE
* The patient will be completely under the anesthetic before surgery begins.
* An incision will be made down the middle of the chest, and the breastbone will be separated so that the heart can be accessed.
* The patient will be put onto a heart-lung machine. During the course of the operation, this machine will do the work usually performed by the heart and lungs, allowing the heart to be stopped so that it can be operated on more easily.
* Another incision is made in the aorta.
* The damaged valve is cut out, and a new valve is sewn into place.
* The aorta is sewn back together.
* The heart is started up again, so that the heart-lung machine can be withdrawn from use.
* The breastbone is wired together.
* The skin incision in the chest is sewn back together.
AFTER THE PROCEDURE
The patient will be monitored in an intensive care unit directly after surgery. It can be noticed that the patient is attached to a number of devices, including:
* Monitors to track the heart rate, breathing rate, blood pressure, and the percentage of oxygen in the bloodstream
* Ventilator tube in the mouth and into the lungs to breathe for the patient, or an oxygen mask or tube to give the patient extra oxygen
* Tubes to drain extra fluid from the chest
* A tube that goes into the nose and down to the stomach that drains the stomach of excess fluid and gas
* A catheter in the bladder to drain urine
* An intravenous line to provide fluids, electrolytes, and pain medications directly into a vein.
TIME TAKEN FOR THE PROCEDURE
2-4 hours
POSSIBLE COMPLICATIONS
* Infection of the skin or breastbone incision
* Bleeding
* Arrhythmias or irregular heart beats. Particularly atrial fibrillation.
* Complications from anesthesia
* Pneumonia
* Scarring
* Blood clots in the new valve, which can travel through the body—if these clots obstruct blood vessels in the body, depriving tissues of oxygen, severe complications can result, such as a stroke or kidney damage
* Mechanical problems with the valve’s functioning
* Endocarditis (inflammation of the sac around the heart)
* Phlebitis (inflammation of a vein)
POSTOPERATIVE CARE
* The patient will probably be given a device called an Incentive Spirometer which the patient will use every couple of hours during the day to make sure that he/she is breathing deeply and keeping the tiny sacs within the lung as open as possible. This can help to avoid the complication of pneumonia.
* The patient will be allowed to walk within 24 hours of the surgery.
* If the patient has a mechanical valve, he/she will have to take blood-thinning medications (anticoagulants) for the rest of the life to avoid developing clots around the valve.
* The patient will need to take an antibiotic whenever he/she have dental procedures or certain surgical and endoscopic procedures.
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| Last Modified :
Monday, May 11, 2009 |
Compiled and edited by the Editorial team and
approved by Expert panel of h4heart.com
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