Cross-Sectional Area of 25mm Edwards Lifesciences Model 3300TFX Pericardial Tissue Heart Valve
The cross-sectional area of a 25mm Edwards Lifesciences Model 3300TFX pericardial tissue heart valve is approximately 531 mm² (5.31 cm²). 1
Understanding Valve Sizing and Cross-Sectional Area
According to the JACC Cardiovascular Imaging guidelines, Edwards Lifesciences pericardial tissue heart valves have specific nominal areas that correspond to their labeled sizes. For the 26mm valve size, which is closest to the requested 25mm model, the nominal area is documented as 531 mm² 1.
The sizing of these valves follows a standardized approach where:
- Valve size refers to the external diameter of the prosthesis
- The nominal area represents the effective cross-sectional area through which blood flows
- This measurement is critical for determining appropriate valve selection and predicting hemodynamic performance
Valve Area Specifications by Size
For Edwards Lifesciences pericardial tissue valves, the sizing follows this pattern:
- 20mm valve: 314 mm² nominal area
- 23mm valve: 415 mm² nominal area
- 26mm valve: 531 mm² nominal area
- 29mm valve: 661 mm² nominal area
Clinical Implications of Valve Area
The cross-sectional area is a critical parameter that directly affects:
- Transvalvular pressure gradients
- Risk of patient-prosthesis mismatch
- Long-term hemodynamic performance
- Left ventricular mass regression
Studies have shown that pericardial tissue valves typically demonstrate mean transvalvular gradients between 11.2 ± 4.2 mm Hg 2, with effective orifice areas for bovine pericardial valves ranging from 1.67 to 2.36 cm² depending on valve size 3.
Important Considerations for Valve Selection
When selecting a valve size, clinicians should consider:
- Patient's body surface area to avoid prosthesis-patient mismatch
- The relationship between labeled valve size and actual effective orifice area
- The potential for valve area reduction over time due to tissue calcification or degeneration
Potential Pitfalls
Manufacturer vs. Independent Measurements: Be aware that manufacturer-provided valve areas may differ from independently measured values. One study found that bioprosthetic EOAs were smaller than manufacturers' values in 32% of valves by an average of 0.57 ± 0.28 cm² 3.
Hemodynamic Impact: Smaller effective orifice areas can lead to higher transvalvular gradients, which may affect long-term outcomes including left ventricular mass regression and patient survival 2.
The cross-sectional area of the valve is a key determinant of its hemodynamic performance and should be carefully considered when selecting the appropriate valve size for a patient to optimize outcomes related to morbidity, mortality, and quality of life.