Other AreasFen-Phen
Health RisksValve Surgery
Heart Valve Surgery
Valvular damage may progress to a point where surgical repair or replacement of the damaged valve is recommended. Surgery is often indicated in cases of severe mitral or aortic valve stenosis and/or insufficiency (regurgitation). In the case of valvular stenosis, surgical intervention is necessary to expand the valve opening so that blood flow through the valve can be increased. In the case of regurgitation, surgery is necessary to stop blood from leaking back through the valve and into the chamber from which it came.
Valve Replacement Surgery
Valvuloplasty, i.e. replacement of the heart valve, is a surgical procedure that can take between 2 and 4 hours and requires the use of general anesthesia and a heart lung machine. During the surgery, the damaged heart valve is removed and replaced with a valve made from either from biologic tissue (human or animal) or artificial (usually plastic) materials. Generally, artificial valves tend to last longer than those made of biological tissue. However, implantation of artificial valves may necessitate anticoagulant medication to help reduce the risk of clotting.
There are different types of artificial (prosthetic) valves. One is the ball-cage. This prosthetic valve consists of a free-moving, small ball that is housed inside of a cage. The flow of blood and pressure generated by the heart's contraction, i.e. systole, push the ball to the top of the cage. When the heart relaxes, i.e. diastole, and the blood flow and pressure decline, the ball drops to the bottom of the cage thereby sealing the valve opening and preventing the blood from leaking backward into the chamber from which it came. Another type of artificial valve is made of artificial compounds and designed in the image of the human valve. It consists of a circular base to which are attached carbon leaflets designed to function as the replaced leaflets once did.
Biologic valves are made from animal or human tissue and are designed to function identically to the replaced valve. These valves are either "stented," i.e. mounted on an artificial ring, or, if no artificial ring is used, "stentless." Sometimes a homograft valve is used to replace the aortic or tricuspid valves. A homograft valve is one that has been donated by a human donor. A bioprosthetic valve is usually one that has been obtained from a pig. Homograft and bioprosthetic valves are "stentless" valves.
Valvular Repair Surgery
Surgeons employ different techniques to repair (rather than replace) faulty valves. The nature of the valve damage, if subject to repair, will dictate the technique used. For example, if calcium deposits have formed on the valve leaflets thereby reducing their mobility, a surgeon may decalcify the leaflets by removing calcium deposits. This should restore flexibility and mobility to the leaflets. In contrast, if the valve leaflets have fused together, the surgeon will separate them by performing a commissurotomy. Other techniques may also be used to improve the mobility, efficiency and functionality of the valve leaflets.
If the structures, chordae tendinea, and/or muscles, papillary muscles that support and control the valves and their function are damaged, the surgeon may utilize techniques designed to strengthen and support these structures and muscles. Sometimes the circular structure that supports the valve leaflets, i.e. the annulus, becomes fatigued and too wide. Surgeons often repair the annulus by tightening its supporting structures and/or by implanting a circular support, i.e. a ring.
Repair of the mitral valve, i.e. mitral valvotomy, involves the surgical widening of the mitral valve opening. This alternative avoids complete replacement of the mitral valve.
A more recent procedure, ballon valvuloplasty, involves the insertion of a balloon, delivered by catheter, to the valve opening. The balloon is threaded into the valve opening and then inflated, Similar to angioplasty, this procedure is designed to increase the size of the valve opening, thereby increasing the excursion of blood through the valve.
