Nested Sheath Inversion for Complete Clot Capture
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Solution Overview
Problem
Existing devices for removing blood clots from the vascular system often fail to capture the clot entirely, leading to fragmented thrombus dislodgement and increased risk of stroke, and may cause endothelial denudation due to high friction with the vessel wall.
Innovation Solution
An obstruction removal device comprising a retriever and a sheath that navigates to the clot in a collapsed configuration, expands to capture it, and uses a flexible sheath to invert over the retriever, ensuring complete capture and minimizing friction with the vessel wall, while optionally incorporating engaging members and a power source for clot dissolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing devices are used to capture clots, then clot removal is attempted, but the devices fail to capture the clot entirely or promote clot fragmentation
Solution Approach 1:
The device employs a nested structure where the retriever is positioned within the sheath, and the sheath can invert over the retriever to enclose the clot. This nested configuration ensures that fragmented clot pieces are contained within the sheath during retrieval, preventing further fragmentation and ensuring complete capture of the thrombus.
Solution Approach 2:
The sheath is designed to invert over the retriever during the procedure. This inversion action transforms the sheath from a delivery configuration to a capture configuration, allowing the distal end of the sheath to engage and contain the clot while the proximal end remains accessible for retrieval. This inverted position enables complete enclosure of the clot without excessive friction.
2Reliability
If existing devices are used to remove clots, then clot capture is attempted, but endothelial denudation occurs due to high friction between the device and vessel wall
Solution Approach 1:
The sheath is constructed as a flexible, thin-walled structure that can conform to the vessel lumen without excessive rigidity. This flexibility allows the sheath to navigate the vasculature with minimal friction against the vessel wall, reducing the risk of endothelial denudation while maintaining the ability to capture and retrieve the clot effectively.
3Reliability
If the retriever is expanded within the obstruction, then complete clot capture is achieved, but device complexity increases
Solution Approach 1:
The sheath serves multiple functions: it acts as a delivery catheter during navigation, transforms into a capture net when inverted over the retriever, and provides containment for fragmented clot pieces during retrieval. This multi-functionality reduces the need for additional separate components, thereby managing device complexity while ensuring complete clot capture.
Data Source
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AI summary
An obstruction removal device is described having a retrieval component used to engage an obstruction within the vasculature and a sheath component that is capable of inverting to fold over the obstruction and the retrieval component. The sheath component helps contain the obstruction and minimizes trauma to the blood vessel during the removal process.