Valve Replacement or Repair is required when a valve does not open or close properly, thus less blood moves through the body or blood leaks backwards. These problems occur due to stenosis (hardening of the valve) or regurgitation (weakening of the valve), which cause the valve to malfunction in either opening all the way or closing tightly. The mitral and aortic valves are on the left-hand side of the heart and work to supply blood to the body; they typically work harder than the valves on the right-hand side of the heart, thus they are the valves that typically require replacement or repair. During this type of valve surgery, the damaged valve is either repaired or it is replaced with either a tissue or mechanical valve.
Heart Valve Repair Surgery
Heart valve repair is a procedure that corrects a defective heart valve. Several different procedures may be performed to repair a valve, depending upon the nature of the valve problem.
- A valvotomy is a type of open-heart surgery in which the surgeon cuts into a valve to repair valvular damage.
- To repair the mitral or tricuspid valve, surgeons may also implant an annuloplasty ring at the point where the leaflets meet the fibrous ring (annulus). An annuloplasty ring is designed to help support the valve so the leaflets can come together properly.
- A complex mitral valve repair may involve a number of techniques including:
- Partial removal or resection of a faulty valve flap (or leaflet)
- Shortening of a faulty valve chord and/or repositioning of the chord
- Insertion of artificial chords
- Reducing the size of the valve ring
- Annuloplasty ring implantation to reinforce the techniques above
Heart Valve Replacement Surgery
Heart valve replacement is an open-heart surgery in which a defective valve that cannot be repaired is then replaced with either a tissue or mechanical valve. There are pros and cons to both tissue (or bioprosthetic) and mechanical valves. Tissue valves are taken from a pig, cow or human donor; although they do not last as long as a mechanical valve, they do not require long-term therapy with anticoagulant medication. On the contrary, mechanical valves are created from manmade materials; they last quite a bit longer but require lifetime therapy with anticoagulant medication.
Mechanical Valves are typically made of metal, carbon and/or artificial materials. These valves are durable. Structural failure of a mechanical valve is very rare. Typically these valves last a lifetime. But all types of mechanical valves require life-long blood thinner therapy (coumadin pill) in order to prevent clots forming on the valve. Thus, the main drawback to mechanical valves is the need for blood thinner therapy. This drawback is offset by the long-term durability of the valve.
Bioprosthetic or Tissue Valves are made of tissue, but they may also have some artificial parts to provide additional support and allow the valve to be sewn in place. Bioprosthetic valves can be made from pig tissue (porcine), cow tissue, pericardial (bovine) tissue, or pericardial tissue from other species. Typically, these valves do NOT require blood thinner pills. However, these valves may, over years, gradually deteriorate and require a repeat operation for removal of the valve and re-replacement.
As you can tell, medical science has yet to develop the perfect artificial heart valve. The primary difference between the two types of valves involves a trade-off between durability (how long will the valve function properly) and thrombosis (risk of blood clots.) Durability indicates how long the valve will last before requiring replacement, and thus, another surgery. Thrombosis or coagulation is the ability of the body to form blood clots. The ability of the blood to clot or clump (coagulation) is important, as it is the body’s way of fighting-off disease and infection. Because the mechanical valve is recognized by the body as artificial, clots can form around the valve potentially causing it to malfunction or causing a stroke. This risk is significantly less with a bioprosthetic valve. In order to fend-off clotting around the mechanical valve, patients are given blood-thinning medications, such as coumadin, to take on a regular basis. However, a blood-thinning medication does increase your risk of bleeding from injury or similar accidents. Therefore, the appropriate level of blood thinner medication will need to be monitored by you and your doctor through periodic blood testing.
There are several lifestyle constraints and adjustments that are common to all valve replacements:
- You will need antibiotics before any dental work or surgery
- You should carry a card that identifies the type of valve you have
- Blood thinner therapy requires you restrain from certain activities that expose you to the risk of trauma
Finally, there are other valve substitutes available such has human preserved valves, non-stented bioprosthetic valves, and procedures that “switch” the aortic and pulmonary valves (so-called “Ross” operation). These options require further discussion with your heart surgeon.
The following chart summarizes the advantages and disadvantages of both a mechanical and bioprosthetic valve.
|Mechanical||Very durable, can last a life-time||
- Must take blood-thinning medication
- Requires on-going monitoring by physician
- Increased risk of bleeding and stroke
|Bioprosthetic/Tissue||Reduced risk of blood clotting||- May require replacement after 10 to 15 years depending on age of patient when valve inserted|
Minimally Invasive Valve Surgery
Minimally invasive heart valve surgery replaces or repairs valves using smaller incisions. With this procedure, the CSA surgeon will either make a smaller incision down the center of the sternum or he will make a small incision above or below the right nipple.