Computed tomography image processing to detect the real mechanism of bioprosthesis failure: implication for valve-in-valve implantation.
Résumé
BACKGROUND AND AIM OF THE STUDY: Transcatheter valve-in-valve implantation is an emerging option for patients with structural deterioration of an aortic bioprosthesis and who are at a high surgical risk. The present case underlines the need for dedicated imaging to accurately understand the mechanism of valve failure, and the feasibility of a valve-in-valve procedure. METHODS: A patient with structural bioprosthetic deterioration at echocardiography was investigated using computed tomography (CT) scanning and novel 3D slicer software. The findings were compared with those revealed at intraoperative pathology. RESULTS: Post-processed CT images showed the bulk of calcifications to be located at the subvalvular level, suggesting the presence of calcified pannus. Pathology of the explanted valve confirmed that the valve stenosis was due primarily to pannus. Misdiagnosed calcified pannus represents a major threat during valve-in-valve procedures, due mainly to embolic risk. CONCLUSION: The 3D slicer elaboration of CT images may be invaluable in providing a precise definition of the mechanism of valve failure, and also to establish the feasibility of either a valve-in-valve procedure or conventional surgery.