Kink Resistant Vascular Graft With Composite Reinforcement
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Solution Overview
Problem
Current vascular grafts, particularly arterial vein grafts (AVGs), face significant challenges due to intimal hyperplasia, leading to luminal narrowing and occlusion, which limits their long-term patency and increases surgical complications such as kinking, stenosis, and thrombus formation.
Innovation Solution
A graft device is designed with a kink resisting element, which can be integrated into the fiber matrix or as a separate component, providing enhanced stiffness, hardness, or resilience to prevent luminal narrowing and radial collapse, utilizing materials like biodegradable metals or polymers to offer temporary or permanent resistance against kinking during and after implantation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a vascular graft is made flexible and compliant to match physiological conditions, then biocompatibility and integration are improved, but kink resistance and structural stability deteriorate
Solution Approach 1:
The graft device combines a flexible tubular conduit with a kink resisting element made of different material properties (biodegradable metal, polymer, or shape memory alloy), creating a composite structure that provides both flexibility for biocompatibility and structural reinforcement for kink resistance
Solution Approach 2:
The kink resisting element is positioned specifically at the distal end of the graft where kinking is most likely to occur during implantation and when navigating anatomical curves, providing localized reinforcement without compromising overall graft flexibility
2Reliability
If the graft structure is reinforced to prevent radial collapse and luminal narrowing, then structural stability is improved, but flexibility and ease of implantation deteriorate
Solution Approach 1:
The kink resisting element utilizes shape memory alloy properties that allow it to dynamically change stiffness - remaining flexible during implantation but providing rigid support when activated by physiological temperature or mechanical stress to prevent radial collapse
Solution Approach 2:
The graft employs a thin-walled tubular conduit that is flexible enough for easy implantation, combined with a kink resisting element that provides structural support only when needed to prevent collapse, maintaining flexibility during normal operation
3Reliability
If a kink resisting element is added to prevent luminal narrowing, then long-term patency is improved, but device complexity increases
Solution Approach 1:
The kink resisting element is nested within or integrated into the graft wall structure, with the element positioned inside or along the tubular conduit, reducing overall device complexity while maintaining the protective function
Solution Approach 2:
The kink resisting element is combined with the fiber matrix or graft wall structure, integrating multiple functions (structural support, kink resistance, and biocompatibility) into a unified device rather than separate 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 kink resisting element effectively minimizes undesirable conditions like buckling and thrombus formation, preserves laminar blood flow, and reduces stress concentration on the tubular wall, thereby improving the long-term patency and reducing surgical complications of vascular grafts.
Implementation Method 1
The kink resisting element can comprise a shape memory material, such as Nitinol, or another alloy of titanium, stainless steel, a cobalt-chrome-molybdenum alloy, silicone, Pebax, polypropylene, nylon, PTFE, polyethylene, UWMWPE, or other polymers
Implementation Method 2
The kink resisting element can comprise a shape memory material, such as Nitinol
Data Source
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AI summary
A graft device including a conduit and a fiber matrix surrounding the conduit for a mammalian patient is disclosed. The graft device further includes a kink resisting element such that the graft device is configured to reduce kinking. Methods and systems for creating kink resistant graft devices are also provided.