Rotatable Inner Cannula Introducer for Stent Deployment
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Solution Overview
Problem
Current introducers for deploying stents or stent grafts face challenges such as complex operation due to multiple trigger wires, increased diameter, and the risk of dislodging the prosthesis during withdrawal, which complicates the deployment and retrieval processes.
Innovation Solution
An endoluminal prosthesis introducer system featuring a rotatable inner cannula with a retaining member and engaging members that allow for controlled longitudinal movement between retaining and releasing configurations, enabling secure deployment and retrieval of stents or stent grafts with reduced complexity and profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple trigger wires are used to control stent deployment, then the stent can be securely retained and deployed, but the device complexity and operational complexity increase
Solution Approach 1:
Multiple trigger wires are merged into a single integrated trigger mechanism. The introducer employs one trigger wire that controls a deployment mechanism capable of releasing multiple apices of the stent simultaneously, eliminating the need for multiple separate trigger wires while maintaining secure retention and deployment control
Solution Approach 2:
The single trigger wire is designed with multi-functionality to perform multiple deployment tasks. It can control the release of multiple stent apices, manage capsule engagement/disengagement, and coordinate sheath movement, replacing the functions previously requiring multiple separate trigger wires
2Reliability
If multiple trigger wires are used to control stent deployment, then the stent can be securely retained and deployed, but the overall diameter of the introducer increases
Solution Approach 1:
Multiple trigger wires are merged into a single integrated trigger mechanism. The introducer employs one trigger wire that controls a deployment mechanism capable of releasing multiple apices of the stent simultaneously, eliminating the need for multiple separate trigger wires while maintaining secure retention and deployment control
Solution Approach 2:
The trigger mechanism is nested within the introducer structure in a space-efficient manner. The single trigger wire is routed through the introducer body and connected to a compact deployment mechanism that can control multiple stent apices, minimizing the overall diameter of the introducer while maintaining full functionality
3Productivity
If the capsule and sheath are engaged during withdrawal, then the introducer can be retrieved, but the edges of the capsule and sheath may dislodge the stent graft
Solution Approach 1:
The stent graft is fully deployed and secured to the vessel wall before the capsule and sheath are engaged for retrieval. The trigger mechanism ensures complete stent expansion and anchoring occurs prior to initiating the engagement sequence, preventing dislodgment during the engagement process
Solution Approach 2:
The traditional sequence is inverted: instead of engaging the capsule and sheath while the stent is still being deployed, the stent is fully deployed first, then the capsule and sheath are engaged for retrieval. This reverse sequence ensures stent stability is established before retrieval actions begin
Data Source
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AI summary
An endoluminal prosthesis introducer (200) may include a rotatable inner cannula (250) including a proximal end. The introducer may include a proximal tip (240) disposed at the proximal end of the inner cannula (250) and including a distal end. The introducer (200) may include a retaining member (260) including an engaging member (268) extending radially outward. The retaining member (260) may be disposed about the proximal end of the inner cannula (250). In response to rotation of the inner cannula (250) with respect to the retaining member (250), the proximal tip may be longitudinally movable relative to the engaging member between a retaining configuration and a releasing configuration. The proximal tip and the engaging member may be spaced from one another by a greater longitudinal distance in the releasing configuration than in the retaining configuration.