Nitinal Clot Retrieval Device for Embolization-Free Thrombus Extraction
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Solution Overview
Problem
Current intravascular thrombus and foreign body removal devices are ineffective in removing organized hard thrombi, often causing embolization and requiring proximal vessel occlusion, which can lead to further ischemia and vessel injury.
Innovation Solution
A deployable system using a pull wire with a distal body comprising memory metal strips that expand to capture and remove obstructions from blood vessels without the need for proximal occlusion, designed to fit within a microcatheter and manufactured from a single nitinol tube using laser cutting and shape-setting techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current intravascular thrombus removal devices are used, then device simplicity is maintained, but effectiveness in removing organized hard thrombi deteriorates and embolization risk increases
Solution Approach 1:
The distal body is nested within the catheter in a collapsed state during delivery, then expands outside the catheter at the target site to capture thrombus. This nesting approach enables the device to be delivered through small vessels while maintaining large expansion capacity for effective thrombus capture without embolization.
Solution Approach 2:
The device transitions from a static collapsed state during delivery to a dynamic expanded state at the target site. The memory metal strips provide dynamic shape change capability, allowing the distal body to expand and contract as needed for thrombus capture and retrieval, improving reliability while preventing embolization.
2Object-generated harmful factors
If proximal vessel occlusion is used to prevent embolization, then embolization risk is reduced, but ischemia and vessel injury increase
Solution Approach 1:
The invention extracts the occlusion function from the proximal vessel and relocates it to the distal body at the thrombus site. The distal body captures and contains the thrombus locally, preventing embolization without requiring proximal vessel occlusion, thereby avoiding ischemia and vessel injury associated with proximal occlusion.
Solution Approach 2:
The distal body acts as an intermediary device between the thrombus and the bloodstream. It captures the thrombus and prevents its release into circulation without requiring occlusion of the proximal vessel, thus mediating between thrombus removal and embolization prevention while avoiding ischemia.
3Ease of operation
If the device is made small and flexible to navigate tortuous vessels, then navigability is improved, but structural strength to dislodge adherent thrombus deteriorates
Solution Approach 1:
The device is delivered in a nested collapsed state within the catheter, allowing it to navigate tortuous vessels with small profile. Upon deployment, the nested structure expands to provide large surface area and structural strength for effective thrombus dislodgment and capture, resolving the contradiction between navigability and strength.
Solution Approach 2:
The device dynamically changes its structural properties from flexible and compact during navigation to rigid and expansive during thrombus engagement. The memory metal strips enable this dynamic transition, providing navigability when collapsed and sufficient strength when expanded to dislodge adherent thrombus.
4Adaptability or versatility
If multiple components are used to achieve deployability, then functionality is improved, but manufacturing complexity increases
Solution Approach 1:
The invention merges the catheter and distal body into an integrated unit where the distal body is formed as a single piece from memory metal strips that are laser-cut and shape-set from a single nitinol tube. This integration maintains deployability functionality while significantly simplifying manufacturing compared to assembling multiple separate components.
Solution Approach 2:
The single nitinol tube serves multiple functions: it provides the structural framework for the distal body, enables memory effect for shape recovery, and allows laser cutting and shape-setting to create the expandable structure. This multi-functionality reduces manufacturing complexity while maintaining deployability.
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
The system effectively captures and removes hard thrombi without embolization, allowing for timely and safe retrieval without causing further ischemia or vessel injury, and is easy to use and manufacture.
Implementation Method 1
a distal body attached to the pull wire, the distal body comprising an interior, an exterior, a proximal end, a distal end, a plurality of proximal memory metal strips located at the proximal end
Implementation Method 2
manufactured from a single nitinol tube using laser cutting and shape-setting techniques
Data Source
AI summary
Catheter-delivered endovascular medical devices are described. The devices may include a pull wire attached to a distal body. The distal body may be formed of a distal body outer body comprising a basket comprised of a plurality of cells defined by a plurality of basket strips and a distal body inner body located in the interior of the distal body outer body and comprising a plurality of distal braided mesh openings formed by a plurality of woven linear strands. The distal braided mesh openings may be smaller than the cells when the device is in the relaxed state. Methods of using and making the devices are also described.