Surface topography of stenotic aortic valves by scanning electron microscopy

Area of Science:

• Cardiovascular Biology
• Biomaterials Science
• Pathology

Background:

• Aortic valve stenosis (AS) is a significant cardiovascular condition requiring valve replacement.
• Understanding the surface morphology of stenotic aortic valves is crucial for elucidating disease mechanisms.
• Previous studies have not comprehensively detailed the ultrastructural surface features of AS.

Purpose of the Study:

• To investigate the detailed surface topography of stenotic aortic valves using scanning electron microscopy (SEM).
• To identify and characterize cellular and extracellular components present on the valve surface.
• To correlate observed surface features with the pathology of aortic valve stenosis.

Main Methods:

• Scanning electron microscopy (SEM) was employed to examine the surface morphology of 19 stenotic aortic valves.
• Valves were obtained from patients undergoing surgical aortic valve replacement.
• Detailed imaging and analysis of surface features, including cellular morphology and extracellular deposits, were performed.

Main Results:

• Uniform endothelial disruption with focal loss of endothelial cells was observed across all examined valves.
• Villi, erythrocytes, and activated leukocytes were identified on the valve surfaces, indicating inflammatory and thrombotic processes.
• Platelets exhibited activation, forming aggregates, and focal deposits of crystalline material, likely calcium, were present in areas of disruption.

Conclusions:

• Stenotic aortic valves exhibit significant surface abnormalities, including widespread endothelial damage and evidence of inflammation and thrombosis.
• The presence of erythrocytes, leukocytes, and activated platelets suggests a complex interplay of cellular events contributing to AS.
• SEM provides valuable insights into the ultrastructural changes associated with aortic valve stenosis, potentially informing future therapeutic strategies.