Stylet-Sheath Penetrating Device for Occluded Vasculature
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Solution Overview
Problem
Current medical devices have low success rates and high complication rates when attempting to recanalize chronically totally occluded blood vessels, particularly due to difficulties in penetrating the proximal cap of occlusions without damaging the surrounding blood vessel.
Innovation Solution
A device comprising an elongate sheath and a stylet with a cutting surface, where the stylet is captively disposed within the sheath to limit axial movement, allowing controlled penetration of the occlusion while minimizing vascular damage, and includes features for centering and advancing through the occlusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional catheter or guidewire is used to traverse an occlusion, then the device can penetrate the occlusion, but the proximal cap configuration causes the device to enter the vessel wall or branch vessel instead of centering on the occlusion
Solution Approach 1:
The patent introduces a specialized penetrating device as an intermediary tool between the conventional catheter and the occlusion. This device includes a stylet with a cutting edge and a protective sheath that can be advanced independently to penetrate the proximal cap, thereby preventing direct damage to the vessel wall while enabling catheter traversal.
Solution Approach 2:
The penetrating device is divided into separable components: a stylet with cutting edge, a protective sheath, and a catheter. The stylet and sheath can be advanced independently through the occlusion, allowing the cutting action to occur at the proximal cap while the catheter follows through the created pathway without causing vascular damage.
2Productivity
If the stylet is allowed to extend freely axially, then it can penetrate the occlusion effectively, but it cannot be retracted to allow catheter exchange or contrast injection
Solution Approach 1:
The patent implements dynamic control of the stylet's axial position through an engagement section with movable engagement features. The stylet can be advanced distally to penetrate the occlusion when needed, then retracted proximally to allow catheter exchange or contrast media injection, providing adaptability while maintaining penetration efficiency.
Solution Approach 2:
The stylet is pre-positioned within the sheath in a retracted state, ready to be advanced distally to penetrate the occlusion. After penetration, the stylet can be retracted to its initial position, allowing the catheter to be exchanged or contrast media to be injected without requiring permanent extension of the penetrating structure.
3Force
If a stiff stylet is used to penetrate the proximal cap, then penetration force is sufficient, but the stylet cannot be easily retracted or positioned precisely
Solution Approach 1:
The stylet is designed with dynamic properties, combining sufficient stiffness to generate the necessary penetration force when advanced distally with the ability to be smoothly retracted proximally. The engagement section provides controlled interaction between the stylet and sheath, allowing precise positioning and easy retraction despite the stylet's rigidity.
Solution Approach 2:
The stylet is pre-positioned within the sheath in a controlled manner, allowing it to be advanced distally with sufficient force to penetrate the proximal cap. After penetration, the stylet can be retracted to its initial position for catheter exchange or contrast injection, combining the necessary penetration force with ease of retraction through proper preliminary positioning and engagement mechanisms.
Data Source
AI summary
Occluded vasculature such as occluded arterial vasculature can be recanalized using a device that is configured to penetrate an occlusion, while limiting a distance that said penetration structure can extend in order to limit inadvertent vascular damage. The device can include an elongate sheath and a stylet disposed within the elongate sheath. The elongate sheath and the stylet can include, in combination, an engagement section that is configured to limit relative axial movement between the elongate sheath and the stylet.