Stent-Graft Suture Locks for Migration Prevention
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Solution Overview
Problem
Current stent-graft devices for aneurysm repair face challenges such as high mortality rates, extended recovery periods, difficulties in suturing grafts to the aorta, and issues with maintaining fluid tight seals and preventing migration, especially in complex or emergency cases, due to their invasive nature and susceptibility to leaks and disruption of normal blood flow.
Innovation Solution
The development of a stent-graft suture lock system that uses modified suture knots with cauterized ends to create tailored profiles, allowing for secure anchoring and sealing of stent-graft components to each other and to vessel walls, preventing relative movement and migration, while maintaining fluid tight seals and accommodating various vessel geometries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional suturing methods are used to attach graft material to stent structures, then the device can be assembled, but the connection strength is insufficient and migration occurs
Solution Approach 1:
The suture knot configuration is modified by changing physical parameters including knot density (number of knots per unit length), knot tightness (constriction force), and suture material properties. These parameter changes transform the suture lock from a simple tying mechanism into a high-friction anchoring system that prevents migration while maintaining flexibility in the graft-stent connection.
2Ease of operation
If the suture ends are left long to allow for adjustment and securing, then the device is easier to assemble, but the suture knots may unravel and lose their locking capability
Solution Approach 1:
The potentially harmful unraveling of suture ends is converted into a beneficial self-locking mechanism. By allowing the suture ends to protrude slightly and fraying them deliberately, the invention creates increased surface area and interlocking fibers that enhance the locking capability. The frayed ends embed into the graft material and stent structure, transforming the weakness of loose ends into a strong anchoring feature that prevents both unraveling and migration.
3Reliability
If the stent-graft device is made more complex with additional anchoring features, then migration prevention improves, but the device complexity and difficulty of manufacture increase
Solution Approach 1:
The suture lock serves multiple functions simultaneously: it attaches the graft material to the stent structure, prevents migration of the entire device, provides adjustment capability for positioning, and creates friction-based anchoring. This multi-functionality eliminates the need for separate anchoring features such as barbs, hooks, or additional fixation elements, thereby maintaining device simplicity while achieving reliable migration prevention through the optimized suture configuration alone.
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 stent-graft suture lock system significantly increases the pull-out force required to separate components, providing a durable and effective solution for maintaining the position of stent-graft devices, reducing the risk of leaks and migration, and facilitating less invasive, percutaneous delivery and deployment.
Implementation Method 1
modified suture knots with cauterized ends
Data Source
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AI summary
Modified suture knots may be utilized to effective anchor one stent-graft to another stent-graft wherein the stent-grafts are normally connected via an interference fit in an overlap configuration. The sutures that are utilized to affix the graft material to the underlying stent structure may be modified to have a profile that allow it to lock (131) and secure it to another stent-graft or a vessel into which it is implanted.