The principal complications that have been reported for bioprosthetic cardiac valves include, but are not limited to , valvular stenosis, valvular and perivalvular insufficiency, calcification, fibrosis, haemolysis, leaflet perforation, rupture or creep, infection, and valve contamination.

Extensive published data suggests that some form of anticoagulation therapy may be beneficial after bioprosthetic cardiac valve replacement in order to reduce the risk of thromboembolic phenomena. In general, for bioprostheses, consideration should be given to anticoagulation therapy for 30 to 60 days after aortic replacement. For patients with moderate to severe atrial enlargement, atrial fibrillation, left atrial thrombus, left atrial wall calcification or other atrial wall abnormalties, or a prior history of thromboembolic events, consideration should be given to prescribing indefinite anticoagulation therapy.

Biological valves closely resemble natural valves in both form and function. They do not require ongoing anticoagulation medication and may provide a better quality of life for the patient. A key disadvantage of tissue valves is their low durability. Since the valves are similar to native valves, they are prone to the same disease characteristics. Valve leaflets can wear out and calcify, impairing the functionality of the valve, resulting in re-operation and valve replacement.
 

You should determine that the leaflets are operating properly and that flow is not occluded by pannus, a vegetation, or some other physical blockage. New valve patients often exhibit gradients that exceed the manufacturer's specification. These gradients are often the result of subvalvular narrowing of the outflow tract due to hypertrophy. You can expect the gradient to diminish over the year following the surgery as the hypertrophy regresses. The problem of the left ventricular outflow dynamic gradient is especially common in patients with aortic stenosis, left ventricular and/or septal hypertrophy and a normal or raised ejection fraction. It is essential to obtain correct and optimal echocardiographic views of the left ventricular outflow tract in calculating indices of valve function and to correct for body surface area to normalize the indices and assess possible valve/patient biological mismatch.