Reverse Deploy Stent Delivery System Proximal Placement
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Solution Overview
Problem
Conventional stent delivery systems face challenges in accurately positioning the trailing end of the stent due to stent foreshortening and variability in vessel diameter, leading to suboptimal placement and potential blockage of major side branches or incomplete coverage of the treatment zone.
Innovation Solution
A stent delivery system that deploys the stent from its proximal end towards its distal end, using a coaxial design with an outer stent cover that is advanced distally to expose and expand the stent radially from the proximal end to the distal end, allowing for precise placement of the proximal end and minimizing the risk of jailing major tributaries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional stent delivery system deploys the stent from distal to proximal end, then the leading end placement can be controlled, but the trailing end placement accuracy is compromised due to stent foreshortening and vessel diameter variability
Solution Approach 1:
The patent inverts the conventional deployment direction by deploying the stent from proximal to distal end instead of distal to proximal. This is achieved by positioning the sheath at the proximal end and advancing it distally, allowing the stent to expand in the opposite direction of conventional systems. This inversion enables accurate control of trailing end placement while maintaining delivery system functionality.
Solution Approach 2:
The system performs preliminary positioning of the proximal end of the stent before full deployment. The sheath is positioned and secured at the desired proximal location first, then the stent is deployed distally from that fixed point. This preliminary action ensures accurate trailing end placement while allowing the rest of the stent to expand along the vessel.
2Manufacturing precision
If the stent is deployed conventionally without preliminary positioning, then deployment is simpler, but accurate placement of the proximal end cannot be achieved to prevent jailing of major side branches
Solution Approach 1:
The system performs preliminary positioning of the proximal end of the stent before full deployment. The sheath is positioned and secured at the desired proximal location first, then the stent is deployed distally from that fixed point. This preliminary action ensures accurate trailing end placement while allowing the rest of the stent to expand along the vessel.
Solution Approach 2:
The sheath acts as an intermediary device that enables precise proximal end placement. By serving as a temporary constraint and positioning mechanism, the sheath allows the physician to accurately position the proximal end of the stent before deployment, preventing jailing of major side branches while maintaining procedural feasibility.
3Measurement precision
If the sheath is advanced distally to deploy the stent from proximal to distal end, then repositioning and precise deployment of the proximal end is enabled, but the delivery system requires a complex coaxial design with multiple shafts and hubs
Solution Approach 1:
The delivery system employs a nested coaxial structure where an inner shaft is positioned within an outer shaft, and a sheath is advanced over the inner shaft. This nesting arrangement allows the sheath to be selectively advanced distally to deploy the stent while maintaining structural integrity and enabling repositioning capability, despite the increased structural complexity.
Solution Approach 2:
The delivery system is segmented into distinct functional components: an inner shaft for support, an outer shaft for structural framework, and a movable sheath for stent deployment control. This segmentation allows each component to perform its specific function independently, enabling precise proximal to distal deployment while managing the overall system complexity through modular design.
Data Source
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AI summary
Systems and methods for stent deployment are provided. One system includes a delivery subsystem having a nose tip coupled with a sheath such that the nose tip and sheath are movable together, wherein the sheath is configured to receive therein a stent for deployment. The stent surrounds an inner shaft of the delivery subsystem. The system further includes an actuating subsystem configured to advance the sheath along the inner shaft from a proximal to distal direction to deliver the stent in a reverse deploy direction.