In vitro two-dimensional echocardiographic imaging of a stented porcine bioprosthetic valve: the bent strut artifact.

BACKGROUND Echocardiographic imaging of a stented valve bioprosthesis can reveal apparent inward deflection of one or more struts. It could be assumed that this finding is related to actual strut distortion as opposed to an artifact of off-axis imaging. OBJECTIVE To determine whether normal (nondistorted) bioprosthetic struts can appear by artifact to be bent inward on two-dimensional echocardiographic imaging. METHODS A production-quality porcine bioprosthetic aortic valve was imaged in vitro using standard two-dimensional echocardiographic techniques. Apparent strut distortion on echocardiographic imaging was investigated relative to prosthesis orientation to the transducer. RESULTS The appearance of inward strut distortion was produced when two of three struts were simultaneously imaged, including imaging in an off-axis long axis orientation and from above or below the prosthesis. CONCLUSION Apparent inward distortion of bioprosthetic struts can be simulated in vitro using a normal, nondistorted valve, and is common if two struts are simultaneously imaged. A finding of inward distortion of strut tips on in vivo imaging should be used with caution, since the finding may not be representative of actual strut anatomy.