Implantable Flexible Valve Member for False-Lumen Backflow
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Solution Overview
Problem
Existing implantable medical devices fail to effectively prevent backflow into a false lumen of dissection, particularly after treating aortic dissection, due to incomplete sealing and potential leakage through downstream tears.
Innovation Solution
An implantable medical device featuring an elongate support member and an unstented flexible tubular valve member with resilient members that self-close upon deployment, using shape-memory materials like nitinol wires to ensure complete occlusion of the false lumen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional candy plug is used to occlude the false lumen, then the upstream end of the false lumen is closed, but backflow from downstream tears cannot be prevented
Solution Approach 1:
The device divides the occlusion function into two segments: the support member handles upstream occlusion while the valve member handles downstream occlusion and backflow prevention. This segmentation allows each component to specialize in preventing backflow from specific locations, achieving complete sealing without requiring a single complex device.
Solution Approach 2:
The valve member acts as an intermediary element between the support member and the false lumen downstream. It provides an additional occlusion mechanism that specifically addresses backflow from downstream tears, mediating the flow control to ensure complete prevention of backflow into the false lumen.
2Ease of operation
If the valve member is made flexible and unstented, then it can be easily deployed and self-closing is achieved, but structural strength and stability are reduced
Solution Approach 1:
The device applies different structural qualities to different components: the support member is rigid and stented to provide structural strength and stability for upstream occlusion, while the valve member is flexible and unstented to enable easy deployment and self-closing function for downstream occlusion. Each component has optimized local properties suited to its specific function.
Solution Approach 2:
The valve member is designed with dynamic characteristics, being flexible and unstented to allow it to collapse and close automatically upon deployment. This dynamic design enables the valve member to adapt to the vascular environment and achieve self-closing without requiring active control mechanisms, while the rigid support member provides stable anchoring.
3Reliability
If resilient members are interwoven with the valve member, then retention is improved, but manufacturing complexity increases
Solution Approach 1:
The resilient members are merged with the valve member through interweaving, creating a single integrated component. This merging ensures that the resilient members remain retained with the valve member during deployment and operation, preventing loss while simplifying the overall device structure compared to separate attached 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
The device effectively prevents backflow into the false lumen by self-closing, facilitating thrombosis and reducing strain on the dissection, thereby minimizing the risk of false lumen expansion and rupture.
Implementation Method 1
The at least one elongate resilient member may be at least one shape-memory material member. The at least one shape-memory material member may be at least one pre-coiled nitinol wire.
Data Source
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AI summary
An implantable medical device for preventing backflow into a false lumen of dissection includes an elongate support member, an elongate flexible tubular valve member having a length, a proximal end, and an open distal end. At least one elongate resilient member extends at least partially along the length of the elongate flexible tubular valve member, the at least one elongate resilient member having a proximal end distal to the elongate support member, a distal end proximal to the open distal end of the elongate flexible tubular valve member, an elongated configuration, and a coiled configuration. The at least one elongate resilient member is unattached to the elongate support member. The at least one elongate resilient member, upon release from a constraining force, is configured to move from the elongated configuration to the coiled configuration thereby closing the open distal end of the elongate flexible tubular valve member.