[Prosthetic valve re-replacement one year after the surgery using a mosaic bioprosthesis]

Area of Science:

• Cardiovascular Surgery
• Biomedical Engineering
• Cardiology

Background:

• Aortic valve stenosis can necessitate aortic valve replacement (AVR). Bioprosthetic valves are commonly used but can be subject to structural valve deterioration.
• Asymmetric septal hypertrophy (ASH) is a condition affecting the ventricular septum, potentially impacting cardiac function and hemodynamics.

Observation:

• A patient experienced recurrent syncope one year after AVR with a Mosaic bioprosthetic valve.
• Echocardiography revealed ASH, left ventricular outflow tract turbulence, and increased pressure gradient, indicating prosthetic valve dysfunction.

Findings:

• Surgical re-exploration identified tears on two coronary cusps of the bioprosthetic valve and subvalvular pannus formation.
• Analysis of the explanted valve showed distortion of the valvular stent, hypothesized to cause leaflet tears through contact.
• Pannus formation was attributed to turbulence induced by ASH and stent distortion.

Implications:

• Stent distortion in bioprosthetic aortic valves, potentially exacerbated by ASH, can lead to leaflet tears and valve failure.
• Pannus formation may be a consequence of altered hemodynamics secondary to ASH and valve stent distortion.
• These findings highlight the importance of considering ventricular septal morphology in the long-term performance of bioprosthetic aortic valves.