Surgical intervention becomes necessary when mitral valve problems become severe. Mitral valve replacement is an open heart surgical procedure involving replacement of the diseased valve with an artificial valve.
The open-heart surgery is performed under general anesthesia and requires the patient to be placed on heart-lung bypass machine. Once the incision is made to expose heart and blood rerouting to bypass machine is complete, mitral valves are exposed and replaced with artificial ones. The procedure overall is a low risk, but post-operative complications such as atrial fibrillation have been reported. Other risks include:
- Reaction to anaesthesia
Mitral valve replacement is considered for patients in functional classes III or IV (NYHA functional classification for heart failure: I = no limitations; II = slight limitation of physical activity; III = marked limitation of physical activity and IV = symptoms at rest) and who do not respond to medical therapy . Mitral insufficiency in the following diseases may also require valve replacement:
- Rheumatic disease
- Rupture of mitral chordae tendineae
- Post infarction papillary muscle rupture
- Intractable infective endocarditis
- Malfunctioning prosthetic valve
- Floppy mitral valve
Artificial valves available are of two types. Mechanical valves are made of metal and pryolytic carbon, while bioprosthetic valves are made of animal tissues. Both the types carry their own risks and have their own set of advantages and disadvantages. The choice of valve depends on:
- Patient’s preference
While mechanical valves have an advantage of being durable, there is a significant risk of clotting on these valves, which directly affects their function. Despite the necessary lifetime intake of anti-coagulants, there is always a risk of stroke. Biological valves on the other hand have an advantage of being free from the risk of clotting, but wear out with time and require replacement. This however, depends on the patient’s age, since an elderly patient may not require the valve to be replaced at all, whereas a younger patient would only carry it for a few years.
 Fowler NO, van der Bel-Kahn JM. Indications for surgical replacement of the mitral valve. With particular reference to common and uncommon causes of mitral regurgitation. The American Journal of Cardiology. 1979 Jul;44(1):148-57.