Aortic valve replacement
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Aortic valve replacement is a surgical procedure in which a patient's aortic valve is replaced by a different valve. The aortic valve can be affected by a range of diseases and require aortic valve replacement. The valve can either become leaky (regurgitant or insufficient) or stuck partially shut (stenotic). Aortic valve replacement currently requires open heart surgery. As of 2006, percutaneous aortic valve replacement is being researched, which allows the implantion of valves using a catheter without open heart surgery.
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[edit] Types of Heart Valves
[edit] Mechanical, Tissue and Homograft Valves
There are two basic types of artificial heart valve, mechanical valves and tissue valves. Tissue heart valves are usually made from animal tissues, either animal heart valve tissue or animal pericardial tissue. The tissue is treated to prevent rejection and to prevent calcification.
There are alternatives to animal tissue valves. In some cases a human aortic valve can be implanted. These are called homografts. Homograft valves are donated by patients and harvested after the patient expires. The durability of homograft valves is probably the same for porcine tissue valves. Another procedure for aortic valve replacement is the Ross procedure or pulmonary autograft. The Ross procedure involves going to surgery to have the aortic valve removed and replacing it with the patient's own pulmonary valve. A pulmonary homograft (a pulmonary valve taken from a cadaver) is then used to replace the patients own pulmonary valve.
[edit] Durability
Mechanical valves are designed to outlast the patient, and have typically been stress-tested to last several hundred years. Tissue valves will typically last between 10-15 years. In younger patients, tissue valves will wear out faster. For this reason, older patients are often recommended tissue valves.
[edit] Surgical Procedure
Aortic valve replacement is most frequently done through a median sternotomy, meaning the chestbone is sawed through. Once the pericardium has been opened, the patient is placed on cardiopulmonary bypass machine, also referred to as the heart-lung machine. This machine takes over the task of breathing for the patient and pumping his blood around while the surgeon replaces the heart valve.
Once the patient is on bypass, an incision is made in the aorta. The surgeon then removes the patient's diseased aortic valve and a mechanical or tissue valve is put in its place. Once the valve is in place and the aorta has been closed, the patient is taken off the heart-lung machine. Transesophageal echocardiogram (or TEE, an ultra-sound of the heart done through the esophagus) can be used to verify that the new valve is functioning properly. Pacing wires are usually put in place, so that the heart can be manually paced should any complications arise after surgery. Drainage tubes are also inserted to drain fluids from the chest and pericardium following surgery. These are usually removed within 36 hours while the pacing wires are generally left in place until right before the patient is discharged from the hospital.
[edit] Hospital Stay and Recovery Time
Immediately after aortic valve replacement, the patient will frequently stay in a Cardiothoracic Intensive Care Unit for 12-36 hours. After this, the patient is often moved to a lower-dependency unit and then to a cardiac surgery ward. Total time spent in hospital following surgery is usually between 4 and 10 days, unless complications arise.
Recovery from aortic valve replacement will take 1-3 months if the patient is in good health. Patients are advised not to do any heavy lifting for 6-8 weeks following surgery to avoid damaging the sternum (breast bone) while it heals.
[edit] Surgical Outcome and Risk of Procedure
The risk of death or serious complications from aortic valve replacement is typically quoted as being between 1-5%, depending on the health and age of the patient, as well as the skill of the surgeon. Older patients, as well as more fragile ones, are sometimes inelegible for surgery because of elevated risks.
[edit] See also
[edit] External links
ValveReplacement.com - Forum for valve replacement patients and their relatives: [1]
| Health science - Surgery - Cardiac surgery - edit |
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| Surgeries/Surgical diseases of the aorta |
| Aortic aneurysm, Aortic dissection, Bentall procedure, David procedure, Marfan syndrome |
| Valvular Heart Disease |
| Aortic valve repair, Aortic valve replacement, Ross procedure Mitral valve repair, Mitral valve replacement Tricuspid valve repair, Tricuspid valve replacement |
| Surgeries/Surgical diseases of the myocardium |
| Coronary artery disease, Ischemic VSD, Maze procedure, Septal myectomy |
| Heart transplantation |
| Ischemic cardiomyopathy, Hypertrophic cardiomyopathy |
| Congenital heart disease |
| ALCAPA, Atrial septal defect, Ebstein's anomaly, Pulmonary stenosis, Tetralogy of Fallot, Transposition of the great arteries, Ventricular septal defect |
