A case of commissural dehiscence 13 years after mitral valve bioprosthesis replacement

Excerpt

The patient, a woman in her 80 s, underwent mitral valve replacement (Medtronic Mosaic 29 mm) 13 years ago for functional mitral regurgitation due to old myocardial infarction. In the past 3 months, the patient was hospitalized three times for heart failure exacerbation, all of which resolved with medical treatment. As in the previous three admissions, transthoracic echocardiography did not reveal the prosthetic valve itself due to prosthetic stent post artifacts, but the apparent deviated mitral regurgitation jet and increased mitral inflow velocity over time led to suspicion of severe mitral regurgitation due to bioprosthetic valve insufficiency, and transesophageal echocardiography (TEE) was performed. TEE showed severe mitral regurgitation, probably due to valve leaflet prolapse of the bioprosthetic valve, as well as mobile structures on the left ventricular side of the prosthetic valve. There were no febrile events, blood cultures were negative, and the mobile structure was considered to be pannus-forming, although it was at atypical sites for pannus formation. Since the patient had severe mitral regurgitation and it was considered difficult to control the heart failure with medical therapy alone, redo mitral valve replacement was performed. Observation of the explanted valve revealed that two of the three commissures of the prosthetic valve had detached from the stent post (commissural dehiscence), and the entire valve leaflet was deviated. The structure that appeared to be a pannus preoperatively was thought to be an observation of one of the two detached commissures (Figs. 1).

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