Valve replacement; Heart valve surgery; Heart valve prosthesis
Heart valve surgery is used to repair or replace diseased heart valves.
There are four valves in the heart:
1. Aortic valve
2. Mitral valve
3. Tricuspid valve
4. Pulmonary valve
The valves are designed to control the direction of blood flow through the heart. The opening and closing of the heart valves produce the sound of the heartbeat.
Heart valve surgery is open-heart surgery that is done while the patient is under general anesthesia. An incision is made through the breast bone (sternum). Tubes are used to re-route the blood away from the heart to a heart-lung bypass machine to keep the blood oxygenated and circulating while the heart is being operated on.
Valves may be repaired or replaced. Replacement heart valves are either natural (biologic) or artificial (mechanical):
- Natural valves are from human donors (cadavers).
- Modified natural valves come from animal donors (porcine valves are from pigs, bovine are from cows) and are placed in synthetic rings.
- Artificial valves are made of metal.
Natural valves rarely require life-long medication to prevent blood clot formation (anticoagulation), whereas artificial valves will require anticoagulation.
Heart valve replacement may be recommended for the following conditions:
- Narrowing of the heart valve (stenosis)
- Leaking of the heart valve (regurgitation)
Valve problems may be caused by infections such as rheumatic fever, birth defects, calcification, or certain medications such as Fen-Phen. Defective valves may cause heart failure (congestive heart failure) and infections (infective endocarditis).
Risks for any anesthesia include the following:
- Reactions to medications
- Problems breathing
Risks for any surgery include the following:
Risks for cardiac surgery include the following:
- Heart attack
- Renal failure
- Temporary postoperative confusion due to the heart-lung machine
Precautions for preventing valve infections are of prime importance, and antibiotics may be prescribed indefinitely or before dental work and other invasive procedures.
Expectations after surgery
The rate of success of heart valve surgery is high - and increasing. The operation provides symptom relief and prolongs life.
The death rate varies depending on the heart valve and averages 2% to 5%. Approximately 2 of every 3 patients who received an artificial mitral valve are still alive 9 years after the surgery.
Life-long anticoagulant therapy is necessary for patients with artificial heart valves. The clicking of the mechanical heart valve may be heard in the chest - this is normal.
The first 2 or 3 days following the operation are spent in an intensive care unit where heart functions can be monitored constantly. The average hospital stay is 1-2 weeks. A few weeks to several months should be allowed for complete recovery, depending on health before surgery.
by David A. Scott, M.D.