Prosthetic Valve Dysfunction




Key Points





  • Bioprostheses may develop transvalvar or perivalvar insufficiency, and mechanical prostheses may develop thrombotic or pannus-mediated obstruction or paravalvar insufficiency.



  • The consequences of valve prosthesis dysfunction may be evident on the chest radiograph; left-sided prosthesis insufficiency or obstruction may result in radiographically evident heart failure.



  • In the absence of another apparent reason, when a patient with a valvular prosthesis develops hemodynamic duress, the prosthesis should be suspected of dysfunction, until disproven.





Prosthesis Dysfunction


The presence of heart failure in a patient with a valve prosthesis warrants due consideration of prosthesis dysfunction.


Bioprostheses are susceptible to transvalvar insufficiency due to wear-and-tear degeneration or infection and to perivalvar insufficiency, which is usually caused by infection ( Fig 12-1 ). Bioprostheses may develop obstruction, likewise due either to wear-and-tear degeneration or infection.


Mechanical prostheses rarely develop significant transvalvar insufficiency but often develop paravalvar insufficiency, which may be sterile, but usually is due to infection, and often includes dehiscence ( Figs. 12-2 and 12-3 ). Obstruction of a mechanical prosthesis may occur because of thrombosis, pannus (fibrous scar tissue) ingrowth, both conditions, or, rarely, to infection with large vegetations ( Figs. 12-4 to 12-7 ).


All mechanical prostheses are apparent on chest radiograph. Most, but not all, bioprostheses are radiographically apparent. Prior sternotomy wires may be the only sign of prior stentless bioprosthesis insertion. For now, all percutaneously or transapically inserted aortic valve bioprostheses are radiographically apparent.




Figure 12-1


Anteroposterior (AP) and abdominal radiographs in a patient with emphysema and an infected, ruptured mitral bioprosthesis resulting in pulmonary edema. At the time of presentation, the bioprosthesis was fortuitously apparent on the abdominal film. The AP radiograph demonstrates a normal cardiothoracic ratio. Sternotomy wires are evident. There are extensive infiltrates, predominantly in the inferior lobes and around the hila. The lungs are overinflated. The abdominal film reveals a stented mitral bioprosthesis at its very top.

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Apr 10, 2019 | Posted by in CARDIOVASCULAR IMAGING | Comments Off on Prosthetic Valve Dysfunction
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