Valvular Heart Disease: Surgical Treatment

In adults in the Western world, cardiac valve lesions are usually caused by degenerative heart disease, which produces aortic valve stenosis and insufficiency and mitral insufficiency. In developing countries, rheumatic heart disease is the most frequent cause of valve lesions, including stenosis, insufficiency, or both. It is the leading cause of mitral stenosis. A common cause of aortic stenosis is a congenitally bicuspid aortic valve that calcifies later in life. Myocardial ischemia, as well as nonischemic cardiomyopathy, can alter mitral valve geometry and result in severe mitral regurgitation. Treatment should be considered for any patient with symptoms of heart valve disease. Asymptomatic patients with critical aortic stenosis should be referred for surgical intervention. In these cases, the onset of symptoms (chest pain, congestive heart failure, and syncope) is associated with poor survival without surgery. Asymptomatic patients with aortic insufficiency should be referred for surgery on the basis of enlarged left ventricular size on echocardiography. In adults, symptomatic aortic valve disease almost always necessitates valve replacement. Stenotic mitral valves can often be repaired by interventional cardiologists, using a double-balloon valvotomy technique. Balloon valvotomy has fallen into disfavor for repairing stenotic aortic valves, because the results are not long lasting. When mitral valve surgery is necessary, repair is preferred over valve replacement. If the anterior leaflet is relatively normal, most mitral lesions can be repaired by means of a combined commissurotomy, posterior leaflet resection, and annuloplasty. When deterioration is advanced, valve replacement is often unavoidable. Recent techniques using artificial chordae tendineae have expanded the indications for mitral valve repair. Tricuspid valve disease can be alleviated by an annuloplasty, a valvotomy, both of these procedures, or valve replacement. Functional tricuspid insufficiency accompanying mitral stenosis will sometimes resolve after correction of the mitral condition. Postoperatively, the main complication of valve replacement is thromboembolism, which is associated mostly with mechanical prostheses, especially in the mitral position. Patients with mitral mechanical prostheses should routinely take an anticoagulant such as sodium warfarin. In addition, those with aortic mechanical prostheses should undergo long-term anticoagulation. Most patients with chronic atrial fibrillation should also receive warfarin. For redo valve procedures, the operative mortality is increased, particularly in patients with poor cardiac functional status and a need for emergency surgery. Limited-access heart valve surgery, with the use of a small incision, is gaining popularity. It may be performed via the port access approach, which entails peripheral perfusion and use of a balloon catheter for aortic occlusion; with standard cannulation and a specially designed aortic cross-clamp; or with a combination of these two approaches. The results are similar to those obtained in conventional procedures using a sternotomy, but some patients report less musculoskeletal discomfort after the limited-access procedure. A number of promising new catheter-based valvetreatment technologies are on the medical horizon but are not yet ready for clinical use.