Porous Graft Device with Zigzag Support for Vascular Patency
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Solution Overview
Problem
Current graft devices, especially those for small diameter applications like coronary artery bypass grafting and peripheral uses, fail to promote endogenous tissue restoration and often occlude due to accumulated proteins and tissues, leading to stenosis and complications such as infections and chronic pain.
Innovation Solution
A graft device featuring an electrospun inner and outer tubular layer sandwiching a zig-zag patterned helix graft support device, with non-laminated areas allowing bending and preventing kinking, and porous biodegradable layers that facilitate cell ingrowth for tissue restoration, replacing the graft over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If synthetic vascular prosthesis (ePTFE or Dacron) are used for small diameter grafts, then structural integrity is maintained, but the grafts fail to remain patent and occlude due to accumulated proteins and tissues
Solution Approach 1:
The graft device employs a porous structure that allows blood vessels to grow through it, enabling tissue integration and preventing occlusion by accumulated proteins and tissues while maintaining structural integrity
Solution Approach 2:
The graft device combines multiple materials including a support device, inner tubular layer, and outer tubular layer to achieve both structural strength and biological compatibility for long-term patency
2Reliability
If native vein segments are used for CABG, then endogenous tissue restoration is achieved, but additional painful surgical procedures are required to harvest the vein
Solution Approach 1:
The graft device enables self-restoration by promoting endogenous tissue growth through its porous structure, eliminating the need for additional surgical procedures to harvest native veins while achieving the same tissue restoration benefits
3Reliability
If electrospun tubular layers are used to promote tissue restoration, then endogenous tissue growth is facilitated, but the graft may lack sufficient structural support
Solution Approach 1:
The graft device combines electrospun tubular layers with a support device to achieve both tissue restoration capability through the porous electrospun structure and sufficient structural support from the embedded support device
Solution Approach 2:
The electrospun inner and outer tubular layers are positioned specifically to facilitate tissue restoration at the graft surface while the support device provides structural support throughout the graft body
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 enables off-the-shelf, non-surgically harvested grafts that promote natural tissue restoration, maintaining structural integrity and preventing kinking, thus offering a durable and effective solution for small diameter vessel applications.
Implementation Method 1
porous biodegradable layers that facilitate cell ingrowth for tissue restoration
Implementation Method 2
electrospun inner tubular layer and an electrospun outer tubular layer
Data Source
AI summary
Graft devices are provided addressing a long need for off-the-shelf small diameter replacement vessels to overcome the drawbacks of currently available alternatives. As they are available off-the-shelf, the graft devices do not require additional surgery to harvest it such as for a vein graft. A porous nature of the graft devices enables restoration process, which results in new natural and patient-own tissue, in contrast to currently existing vascular prosthesis that can never fully heal. A built-in graft support device over-comes the limited kink-resistance that is typical for these kinds of (electro-spun) porous devices. A zigzag pattern with alternating laminating and non-laminating areas enables the incorporation of the graft support device without the need for additional suturing or connecting the inner and outer layer for good lamination, while maintaining adequate kinkresistance.