Umbrella-Mesh Retrieval Stent for Reliable Thrombus Removal
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Solution Overview
Problem
Conventional thrombectomy devices lack radial strength, leading to deformation and low efficiency in capturing and removing thrombi, stones, and other occlusive objects, with a high risk of distal occlusion and vessel damage.
Innovation Solution
A self-expandable retrieval stent made from a mesh tube with a distal curved section and a proximal loading section, featuring an umbrella-shaped mesh surface concave toward the proximal end, providing enhanced radial support and compliance, reducing deformation and vessel damage during thrombectomy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional thrombectomy structures are used, then the device can be advanced to the thrombus site, but the structure lacks radial strength and deforms when compressed by the thrombus
Solution Approach 1:
The retrieval device is divided into multiple segments: a proximal loading section, a distal curved section, and a mesh tube structure. This segmentation allows each part to be optimized independently - the mesh tube provides radial strength while the curved sections facilitate navigation and thrombus capture
Solution Approach 2:
The device combines different structural elements with complementary properties: a mesh tube for radial support, curved sections for flexibility and navigation, and a combination structure that integrates both rigid and flexible components to achieve both strength and compliance
2Reliability
If conventional thrombectomy structures are used, then the device can be deployed, but the thrombus tends to fall off the structure surface or escape through the openings during withdrawal
Solution Approach 1:
The distal curved section features a curved geometry that creates a concave surface, allowing the thrombus to be captured and retained in the curvature. This curved design prevents the thrombus from falling off the structure surface during withdrawal while maintaining access for removal
Solution Approach 2:
The mesh opening density is varied locally - denser openings in certain regions for secure thrombus capture, and sparser openings in other regions for controlled removal. This local variation in mesh quality allows the device to hold the thrombus reliably while enabling its subsequent removal
3Reliability
If conventional thrombectomy structures with large contact area are used, then the device can capture adherent thrombus, but the blood vessel is more likely to be damaged
Solution Approach 1:
The device incorporates a proximal loading section that can be dynamically adjusted - it can be compressed to a smaller profile for navigation and then expanded at the target site. This dynamic capability allows the device to adapt to different vessel sizes and thrombus locations, reducing the risk of vessel damage while maintaining capture effectiveness
Solution Approach 2:
The distal curved section creates a concave surface that captures adherent thrombus through its curved geometry rather than requiring large flat contact areas. This curved design reduces the overall contact area with the vessel wall while still effectively capturing and detaching adherent thrombus
4Productivity
If conventional thrombectomy structures are used, then the device can be advanced, but it is difficult to detach, capture and remove firmly adherent thrombus
Solution Approach 1:
The device performs preliminary actions during advancement - the proximal loading section is compressed to navigate through the vessel, then expanded at the target site to engage the thrombus. This preliminary compression and expansion sequence prepares the device for effective thrombus capture and removal
Solution Approach 2:
The combination structure allows dynamic adjustment of the proximal loading section, enabling it to be compressed for navigation and then expanded to engage firmly adherent thrombus. This dynamic capability significantly improves the ability to detach and remove difficult-to-reach thrombus
Data Source
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Figure 4c~4f
AI summary
The present invention provides a retrieval stent, retrieval device and retrieval system. The retrieval system includes the retrieval device, a delivery device and an aspiration device. The delivery device is able to load the retrieval device and deliver it to a target lesion site. The aspiration device can be connected to the delivery device and is used to apply a suction force through the delivery device to aspirate an occlusive object from the target lesion site. The retrieval device includes a core tube and the retrieval stent. The retrieval stent is disposed over an outer circumference of the core tube at a distal end thereof, and the retrieval stent is attached to the core tube through a proximal loading section. The retrieval stent is self-expandable and fabricated from a mesh tube. A portion of the mesh tube is folded toward an exterior of the retrieval stent to form a distal curved section of the retrieval stent, and the proximal loading section of the retrieval stent is provided by a non-folded portion of the mesh tube. The distal curved section includes an umbrella-shaped mesh surface that is concave toward a proximal end. More efficient and better treatment of a thrombus, stone or other occlusive object can be achieved.