Braided Clot Retrieval Sleeve With Closable Funnel Opening
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Solution Overview
Problem
Conventional retrieval devices for brain emboli face challenges in safely capturing large clots, often leading to clot fragmentation and release of harmful particles due to inadequate engagement and retraction capabilities.
Innovation Solution
A catheter system with a funnel-like sleeve that transitions between collapsed and expanded states, featuring a braided structure and a mechanism for controlled partial deployment, along with suction and closure mechanisms to securely trap and retrieve clots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional retrieval catheter with a funnel-like trap is used to capture large clots, then the clot engagement capability is improved, but clot fragmentation occurs and harmful particles are released into the bloodstream
Solution Approach 1:
The retrieval system is divided into multiple functional segments: an inner catheter, an outer sheath, a funnel-like trap, and a closure mechanism. The funnel trap is further segmented into a conical portion for engagement and a cylindrical portion for containment. This segmentation allows each component to perform its specific function optimally - the conical portion engages the clot gently, while the cylindrical portion with closure mechanism secures it without fragmentation.
Solution Approach 2:
The closure mechanism is prepared in advance within the catheter system, ready to be deployed immediately after clot engagement. The pull wire closure mechanism is pre-positioned to cinch the distal opening of the funnel trap, ensuring that once the clot is captured, it is immediately secured without risk of fragmentation or particle release during retraction.
2Quantity of substance
If the funnel-shaped sleeve is fully expanded to capture large clots, then the capture volume is improved, but the device complexity and difficulty of controlled deployment increase
Solution Approach 1:
The funnel-shaped sleeve is designed to be partially expanded rather than fully expanded during initial clot engagement. The conical portion extends distally from the catheter to engage the clot, while the remainder stays within the delivery system. This partial expansion reduces device complexity and improves controllability while still providing sufficient capture volume for large clots.
Solution Approach 2:
The funnel-shaped sleeve transitions dynamically between collapsed, partially expanded, and fully expanded states during the retrieval process. The braided construction allows the sleeve to expand and contract controllably in response to differential pressures and mechanical forces applied during deployment and retrieval, enabling adaptable engagement of clots of varying sizes.
3Stability of the object's composition
If the sleeve is made rigid to maintain shape during retraction, then the structural stability is improved, but the ability to navigate through vessels and deploy controllably deteriorates
Solution Approach 1:
The funnel-shaped sleeve is constructed from a flexible braided material that can be covered with a polymer coating such as PTFE or polyurethane. This flexible construction allows the sleeve to navigate tortuous vessels and deploy controllably, while the braided structure provides sufficient radial strength to maintain the funnel shape during clot engagement and retraction.
Solution Approach 2:
The sleeve combines braided material (providing structural integrity and shape memory) with a polymer coating (providing smooth surface for vessel navigation and hydrophobic properties). This composite construction achieves both flexibility for navigation and stability for maintaining the funnel shape during operation.
4Productivity
If the distal opening is left open to allow clot entry, then the clot engagement efficiency is improved, but the risk of clot particle release during retraction increases
Solution Approach 1:
The closure mechanism is pre-positioned within the catheter system, ready to be activated immediately after clot engagement. The pull wire runs through the catheter and can be pulled to cinch the distal opening of the funnel trap, sealing the captured clot before retraction begins, thereby preventing particle release while maintaining high engagement efficiency.
Solution Approach 2:
The funnel trap is segmented into a conical engagement portion and a cylindrical containment portion with a closable distal opening. This segmentation allows the distal opening to remain open during engagement for efficient clot capture, then be closed to seal the clot securely during retraction, preventing particle release.
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
Enhances the ability to capture large clots without fragmentation by allowing controlled engagement and retraction, minimizing the release of clot particles into the bloodstream.
Implementation Method 1
a funnel-shaped sleeve attached to the inner tube and being configured for transitioning between a collapsed state when sequestered within the outer tube and an expanded state when advanced out of the outer tube
Implementation Method 2
the closure mechanism includes a pull wire. the pull wire cinches closed the distal opening
Implementation Method 3
the catheter system further comprises a conduit for applying suction within the braided sleeve. the catheter system further comprises a vacuum source in communication with the conduit
Data Source
AI summary
A system for retrieving material from a biological vessel comprises an outer tube, advanceable through the biological vessel toward the material. At a distal part of the system, the system comprises a sleeve formed from wires that are arranged in a braid and covered with a polymer. A shaft is positioned within the outer tube, and attached to the sleeve such that the shaft is adapted to transition the sleeve between a collapsed state by drawing the sleeve proximally into the outer tube and an expanded state by advancing the sleeve distally out of the outer tube. A portion of a distal end of the sleeve includes leaflets formed by wires, the leaflets extending circumferentially around 25-75 percent of the distal end of the sleeve and protruding distally by 1-3 mm. Other embodiments are also described.