Expandable Graft Anchoring Frame for Stent Migration Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing stent grafts for treating vascular aneurysms face issues such as migration due to limited vessel wall area for fixation, poor tissue fixation capabilities, and mispositioning during delivery, leading to potential leakage and unwanted blockage of branching arteries.
Innovation Solution
A tissue anchoring device with a radially expandable frame and deployable struts that transition from a collapsed to an expanded configuration, featuring angled expandable struts and tissue-penetrating anchors, stabilized by a dual balloon catheter system for precise deployment and secure anchoring within the vessel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stent graft is used to treat vascular aneurysms, then the aneurysm can be sealed off, but the stent graft may migrate over time due to blood flow forces and arterial pulsation
Solution Approach 1:
The stent graft is divided into modular components with separate anchoring mechanisms. The frame includes multiple expandable struts that can be independently deployed to engage with the vessel wall at different locations, creating discrete anchoring points that prevent migration while maintaining the integrity of the graft structure.
Solution Approach 2:
Anchors are pre-positioned on the stent graft frame before deployment. These anchors are configured to engage with the vessel wall immediately upon expansion, ensuring that the graft is secured to the tissue before blood flow forces can cause migration. The anchors are designed to be deployed in a controlled manner during the procedure.
2Reliability
If anchors are added to the stent graft for tissue fixation, then migration can be prevented, but the device complexity increases
Solution Approach 1:
The anchors are integrated directly into the stent graft frame structure, combining the anchoring function with the support structure. The expandable struts serve dual purposes: providing structural support for the graft and acting as anchors to secure the graft to the vessel wall. This merging of functions reduces the need for separate, complex anchoring devices.
Solution Approach 2:
The anchors utilize shape memory alloy properties to change their configuration based on temperature or mechanical stress. This allows the anchors to be compact during delivery and then expand to their full anchoring configuration upon deployment, reducing the complexity of the delivery system while maintaining effective anchoring.
3Ease of operation
If the stent graft is delivered through a catheter, then minimally invasive treatment is achieved, but mispositioning can occur during delivery
Solution Approach 1:
The stent graft frame includes dynamic elements such as expandable struts and movable anchors that can be adjusted during the delivery process. This allows the graft to be positioned and anchored in real-time during deployment, enabling correction of positioning errors while maintaining the minimally invasive approach through the catheter.
Solution Approach 2:
The delivery system incorporates imaging and sensing capabilities that provide real-time feedback on the graft's position within the vessel. This feedback allows the operator to adjust the graft positioning during delivery to ensure accurate placement, preventing mispositioning while maintaining the minimally invasive delivery method.
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
Ensures stable anchoring of stent grafts, maintaining accurate positioning and preventing migration, while minimizing the risk of leakage and blockage, thereby enhancing the effectiveness of vascular aneurysm treatment.
Implementation Method 1
a radially expandable frame configured to transition between a collapsed configuration and an expanded configuration
Implementation Method 2
Each of the plurality of expandable struts interconnecting adjacent longitudinal struts may be configured to expand circumferentially from a V shape in the collapsed configuration to a dome shape in the expanded configuration
Implementation Method 3
the tissue penetrating portion of each anchor may be configured to penetrate a graft disposed within the biological vessel and at least an inner wall of the biological vessel
Implementation Method 4
each anchor may comprise at least two prongs configured to transition between a restrained state where the at least two prongs are juxtaposed and an unrestrained state where the at least two prongs are deflected away from each other
Implementation Method 5
a dual balloon catheter system for precise deployment and secure anchoring within the vessel
Data Source
AI summary
Tissue anchoring devices including a radially expandable frame having a plurality of longitudinal struts and a plurality of deployable anchors configured to penetrate a stent graft and tissue, and systems for delivering and deploying the tissue anchoring devices at a target location are provided. The adjacent longitudinal struts are interconnected by a plurality of expandable struts, and a ring of these expandable struts may be angled radially outward relative to a remainder of the expandable struts in an expanded configuration. Each of the plurality of anchors may include one or more anti-buckling mechanisms to facilitate penetration into the graft/tissue.