Threaded Valve Delivery Sheath for Controlled Aortic Deployment
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Solution Overview
Problem
Existing prosthetic heart valves, particularly self-expanding ones, face challenges in precise and controlled deployment due to their tendency to 'jump' out of the delivery sheath, and may not adequately anchor to non-stenotic native valves, often requiring additional anchoring devices that can complicate future interventions.
Innovation Solution
A delivery apparatus with a first elongated shaft and a rotatable second shaft featuring external threads or grooves, a sheath retaining ring, and a valve-retaining mechanism, allowing controlled axial movement of the delivery sheath to deploy the prosthetic valve precisely and minimize anchoring into non-diseased areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a self-expanding prosthetic valve is advanced from the delivery sheath, then the valve expands to its functional size, but the valve tends to jump out quickly from the end of the sheath due to outward biasing force, making controlled delivery difficult
Solution Approach 1:
The delivery sheath applies a constraining force opposite to the outward biasing force of the self-expanding valve frame before deployment. The sheath is designed to resist the expansion force until the operator intentionally releases it, preventing premature jumping and enabling controlled delivery to the target site.
Solution Approach 2:
The prosthetic valve is pre-loaded into the delivery sheath in a compressed state before the procedure. The sheath maintains the valve in this constrained configuration during navigation through the vasculature, and only releases it when positioned correctly at the implantation site, ensuring controlled deployment.
2Reliability
If anchoring devices are added to the prosthetic valve to resist migration, then anchoring force is improved, but the devices extend into non-diseased areas of the vasculature, complicating future interventions
Solution Approach 1:
The anchoring mechanism is designed to engage only with the diseased native valve tissue at the implantation site, not with the healthy vasculature. The prosthetic valve frame is configured to provide sufficient anchoring force locally at the valve annulus without extending into non-diseased areas, preserving future intervention options.
3Reliability
If additional anchoring devices are added to the prosthetic valve, then the valve can resist migration, but the device complexity increases
Solution Approach 1:
The anchoring function is merged into the prosthetic valve frame itself rather than being a separate component. The frame is designed with integrated features that provide both structural support and anchoring capability, eliminating the need for additional separate anchoring devices and reducing overall system complexity.
Solution Approach 2:
The prosthetic valve frame serves multiple functions simultaneously: it provides the structural support for the valve leaflets, delivers the self-expanding mechanism, and provides anchoring to resist migration. This multi-functionality eliminates the need for separate dedicated anchoring components.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables precise and controlled deployment of prosthetic valves, reducing trauma risk and simplifying future interventions by minimizing anchoring into non-diseased tissue, thus enhancing procedural control and safety.
Implementation Method 1
The distal end portion of the second shaft has an outer surface comprising external threads or grooves. A sheath retaining ring is disposed on the threads or grooves of the second shaft and is fixed against rotational movement upon rotation of the second shaft. The second shaft is configured to be rotatable relative to the first shaft such that rotation of the second shaft causes the sheath retaining ring to move axially along the threads or grooves
Data Source
Figure 1~2
Figure 3~4
Figure 5A
AI summary
Certain embodiments of the present disclosure provide a prosthetic valve (10) (e.g., prosthetic heart valve) and a valve delivery apparatus for delivery of the prosthetic valve to a native valve site via the human vasculature. The delivery apparatus is particularly suited for advancing a prosthetic heart valve through the aorta (i.e., in a retrograde approach) for replacing a diseased native aortic valve. The delivery apparatus in particular embodiments is configured to deploy a prosthetic valve from a delivery sheath (106) in a precise and controlled manner at the target location within the body.