Semi-Constrained Stent Assembly for Branch Vessel Alignment
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Solution Overview
Problem
Establishing reliable access to branch vessels during endovascular aortic repair (EVAR) procedures is challenging due to uncertainties in stent deployment, potential vascular injury, and difficulties in accurately aligning fenestrations with branch vessels, especially with in-situ fenestration, pre-fenestration, and integrated branched stent systems.
Innovation Solution
A stent with a semi-constrained design featuring a constrained section and non-constrained sections, assisted by constraining members, allows for controlled expansion and alignment with branch vessels, facilitated by a delivery assembly and device that maintains the stent in a semi-constrained state for precise fenestration and super-selection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If in-situ fenestration technique is used to create holes in straight tubular stents, then branch vessel access can be established, but the branch vessel orifice may be obstructed by metal stent segments making perforation difficult and potentially causing vascular injury
Solution Approach 1:
The stent is pre-designed with fenestrations and covered stent segments at the intended fenestration locations before implantation. This preliminary preparation eliminates the need for post-implantation perforation operations, avoiding the risks of vascular injury and metal segment obstruction that would otherwise occur during in-situ fenestration attempts
Solution Approach 2:
A guiding catheter is introduced as an intermediary tool to navigate through the main stent's fenestrated regions and reach the branch vessel orifices. The catheter's flexible structure allows it to pass through the covered stent segments and fenestrations without causing vascular injury, establishing a safe pathway for subsequent branch stent delivery
2Manufacturing precision
If pre-fenestration technique is used with pre-incorporated fenestrations during stent manufacturing, then fenestration alignment can be improved, but accurate alignment of fenestration region with branch vessel orifice remains difficult after stent deployment
Solution Approach 1:
The stent is pre-manufactured with fenestrations and covered segments positioned at specific locations corresponding to branch vessel orifices. This preliminary configuration ensures that when the stent is deployed, the fenestrated regions are already aligned with the target branch vessels, eliminating the need for post-deployment adjustment and ensuring accurate alignment
Solution Approach 2:
The covered stent segments and fenestrated regions are designed with distinct radiopaque characteristics that enhance visibility under angiography. This allows operators to clearly identify the fenestration locations and confirm accurate alignment with branch vessel orifices during the procedure
3Adaptability or versatility
If integrated branched stent systems are used, then the entire stent can be positioned near the branch vessel, but the system requires pre-guidance and is limited to specific vascular regions
Solution Approach 1:
The stent system is divided into distinct segments: a main stent body with fenestrated regions, covered stent segments, and separate branch stents. This segmentation allows each component to be delivered and positioned independently through the guiding catheter, providing flexibility for various vascular configurations without requiring complex pre-guidance systems
Solution Approach 2:
The main stent is designed with multiple fenestrated regions that can accommodate different branch vessel configurations. The same stent design can be used for various vascular regions and anatomical variations, eliminating the need for region-specific customized stent systems and reducing overall device complexity
4Ease of operation
If conventional stent deployment is used, then the stent springs open after implantation, but this makes it difficult to accurately align the fenestration region with the branch vessel orifice
Solution Approach 1:
The fenestrations and covered stent segments are pre-configured in the correct positions before stent delivery. The stent is designed to maintain its pre-configured shape during deployment, ensuring that the fenestrated regions automatically align with the branch vessel orifices as the stent expands, eliminating the need for post-deployment realignment
Solution Approach 2:
The fenestrated regions and covered stent segments are designed with enhanced radiopacity that makes them clearly visible under angiography during deployment. This allows operators to visually confirm accurate alignment with branch vessel orifices in real-time, ensuring precise fenestration alignment
Data Source
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AI summary
The present application relates to a stent, an inner catheter, a delivery assembly, and a delivery device. The stent includes a stent body (1000) and a first constraining member (2000). The stent body (1000) has a stent lumen extending therethrough in an axial direction, and a stent window (1100) communicating with the stent lumen is defined on a surface of the stent body (1000). The tent body 1000) includes a constrained section (1000a) and a non-constrained section (1000b) distributed along the axial direction, and the stent window (1100) is located between the constrained section (1000a) and the non-constrained section (1000b). The first constraining member (2000) is disposed on the constrained section (1000a) of the stent body (1000).