Is the 25mm Inspiris a Tissue Valve?
Yes, the Inspiris RESILIA is a bioprosthetic (tissue) valve made from bovine pericardial tissue, available in multiple sizes including 25mm. 1, 2
Valve Characteristics
The Inspiris RESILIA represents a newer-generation bioprosthetic valve with specific design features:
Tissue composition: Constructed from bovine pericardial tissue with RESILIA technology, which incorporates an improved anti-calcification treatment aimed at reducing structural valve deterioration 1, 2
Available sizes: The valve comes in multiple annulus sizes, with 23mm and 25mm being the most commonly implanted sizes in clinical practice 2
Expandable design: The valve annulus is specifically engineered to dilate during transcatheter valve-in-valve procedures (TAV-in-SAV), expanding from approximately 22mm to 24mm when a transcatheter valve is deployed inside it 1
Clinical Context for Valve Selection
When considering a 25mm Inspiris for aortic valve replacement:
Age considerations: Bioprosthetic valves are reasonable in patients over 70 years of age, and either bioprosthetic or mechanical valves are reasonable for patients between 60-70 years 3
Anticoagulation avoidance: A bioprosthesis is recommended in patients of any age for whom anticoagulant therapy is contraindicated, cannot be managed appropriately, or is not desired 3
Younger patients: For patients under 60 years, mechanical prostheses are generally reasonable if anticoagulation is not contraindicated, though the Inspiris has been studied in younger populations (mean age 58 years) with encouraging 1-year outcomes 3, 2
Hemodynamic Performance
The 25mm Inspiris demonstrates favorable hemodynamic characteristics:
Pressure gradients: The valve shows mean transvalvular pressure gradients of approximately 9 mmHg (IQR 7-11 mmHg) at early follow-up, which is lower than some predecessor valves 4
Patient-prosthesis mismatch: Severe patient-prosthesis mismatch occurs in only 1.2% of cases, indicating appropriate sizing for most patients 2
Valve regurgitation: Severe intravalvular regurgitation is rare (0.6%) when properly implanted 2
Important Caveats
Critical limitation: While the Inspiris shows promising early results in the aortic position, it demonstrates poor durability when implanted in the pulmonary position (native right ventricular outflow tract), with 18-month freedom from valve failure of only 59% 5. This is specific to pulmonary use and does not apply to aortic valve replacement.
Durability concerns: Despite improved anti-calcification technology, one case report documented structural valve deterioration requiring TAV-in-SAV at only 22 months in a hemodialysis patient, though this represents an extreme scenario with accelerated calcification risk 1
Long-term data: The valve has only been available since 2017, so long-term durability data beyond 5 years remains limited, and extended follow-up is mandatory to fully assess the benefit of RESILIA tissue technology 2