Hybrid Intraluminal Device Alternating Wireforms
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Solution Overview
Problem
Conventional intraluminal grafts, particularly self-expanding and pressure-expandable types, face challenges in conforming to irregularly shaped or angulated vascular anatomy, leading to suboptimal attachment and seal, especially in regions like the thoracic aortic arch and abdominal aortic aneurysms, due to their inherent material properties and design limitations.
Innovation Solution
The intraluminal device incorporates a tubular main body with alternating groups of self-expanding and balloon-expandable wireforms, allowing for enhanced conformability and attachment to irregular vessel walls by using balloon-expandable wireforms to support protrusion portions, which expand to match the vessel's contours, combined with self-expanding wireforms for radial elasticity and recoil resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If self-expanding wireforms are used to provide radial elasticity and recoil resistance, then the graft maintains structural integrity, but the graft cannot conform well to irregularly shaped or angulated vessel walls
Solution Approach 1:
The graft divides the support structure into two distinct segments: self-expanding wireforms for radial stability and pressure-expandable wireforms for conformability. This segmentation allows each type to perform its specialized function without compromising the other.
Solution Approach 2:
The graft combines two different types of wireforms (self-expanding and pressure-expandable) into a composite structure. This composite design integrates the advantages of both materials: the elastic recoil resistance of self-expanding wireforms and the plastic deformability for conforming to irregular shapes.
2Shape
If pressure-expandable wireforms are used to improve conformability to vessel contours, then the graft adapts better to irregular anatomy, but the graft lacks sufficient radial and hoop strength
Solution Approach 1:
The graft segments the support function between two wireform types: pressure-expandable wireforms provide conformability to irregular shapes, while self-expanding wireforms provide the necessary radial and hoop strength.
Solution Approach 2:
The composite structure combines pressure-expandable wireforms (which conform to vessel contours) with self-expanding wireforms (which provide radial and hoop strength), allowing the graft to simultaneously achieve both conformability and structural strength.
3Shape
If a rigid bare stent is introduced to force radial expansion and improve vessel wall apposition, then the graft achieves better attachment, but the procedure becomes more complex and the stent may damage the graft fabric
Solution Approach 1:
The invention merges the functions of the bare stent and the graft into a single integrated structure. The pressure-expandable wireforms are built into the graft itself, eliminating the need for a separate bare stent implantation step and reducing procedural complexity.
Solution Approach 2:
The pressure-expandable wireforms are pre-integrated into the graft structure during manufacturing, so the conformability function is already prepared before implantation. This preliminary integration avoids the need for subsequent stent placement and potential fabric damage.
4Device complexity
If self-expanding grafts are used to simplify the procedure, then the implantation is less complex, but the graft foreshortens and recoils within the vessel
Solution Approach 1:
The graft segments the expansion mechanism: self-expanding wireforms provide initial deployment simplicity, while pressure-expandable wireforms provide stable positioning by allowing controlled expansion to match the vessel length, preventing foreshortening and recoil.
Solution Approach 2:
The composite wireform structure combines self-expanding and pressure-expandable elements, where the self-expanding portion enables simplified implantation while the pressure-expandable portion ensures stable positioning without foreshortening or recoil.
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
This design enables precise placement and secure attachment of the graft to irregularly shaped vessels, reducing the risk of dislodgement and leakage, while providing improved conformability and hoop strength to match the vessel's contours, thus enhancing the treatment of aneurysms and similar vascular damage.
Implementation Method 1
Self-expanding intraluminal grafts, are supported and/or attached via resilient or shape-memory material such as spring steel or Nitinol
Implementation Method 2
Pressure-expandable intraluminal grafts are supported and/or attached via plastically deformable material such as stainless steel or Elgiloy that is initially formed in its radially compact diameter
Data Source
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AI summary
An intraluminal device has a tubular main body and a plurality of expandable wireforms. The wireforms are grouped in a first group of one or more self expandable wireforms and a second group of one or more pressure expandable wireforms and arranged in alternating groups of wireforms comprising the first group and the second group. Also described is an intraluminal device for positioning within a branched vessel of a patient having an elongate main body and a branch portion. The branch portion is independently moveable relative to the main body.