Bi-directional Stent Delivery via Shuttle Sheath Coupling
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Solution Overview
Problem
Current stent delivery systems face challenges in precise deployment, particularly for self-expanding stents, which can 'jump' away from the delivery catheter during deployment, and lack bi-directional deployment capabilities, leading to potential inaccuracies in placement, especially in complex anatomical areas like the venous system.
Innovation Solution
A bi-directional stent delivery system featuring a shuttle sheath and shafts with reversible coupling mechanisms, allowing for radial expansion from either the proximal or distal end, enabling precise control and deployment direction selection, and accommodating multiple stents with different release modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional stent delivery system is used for self-expanding stents, then the stent can be delivered to the treatment site, but the stent may jump away from the delivery catheter during deployment causing placement inaccuracy
Solution Approach 1:
The delivery system employs nested shafts where an inner shaft is contained within an outer shaft. The inner shaft carries the stent and can be advanced independently to precisely position the stent at the treatment site while the outer shaft provides structural support and containment, preventing the stent from jumping away during deployment.
Solution Approach 2:
The system allows dynamic control of shaft movement where the inner and outer shafts can move relative to each other. The inner shaft can be advanced distally while the outer shaft remains stationary or moves at a different rate, enabling precise control over stent deployment timing and position to maintain placement accuracy.
2Adaptability or versatility
If a conventional stent delivery system with fixed release mode is used, then the system structure is simple, but it cannot accommodate bi-directional deployment needs in complex anatomical areas
Solution Approach 1:
The delivery system is designed with universal functionality to support both proximal and distal stent release modes. The shaft coupling mechanisms can be configured in different states, and the system can adapt to different anatomical configurations, allowing a single device to perform multiple deployment functions without requiring separate specialized systems.
Solution Approach 2:
The coupling between the inner and outer shafts is designed to be dynamically configurable. The shafts can be coupled or decoupled based on the desired deployment direction, allowing the system to adapt its configuration during the procedure. This dynamic reconfigurability enables bi-directional deployment capability while maintaining a relatively simple base structure.
3Ease of operation
If the inner shaft is advanced distally to deploy the stent, then the stent expands from proximal to distal end, but the outer shaft cannot be simultaneously retracted proximally for optimal control
Solution Approach 1:
The delivery system is segmented into independent inner and outer shafts that can move relative to each other. This segmentation allows the operator to control each shaft independently - advancing the inner shaft distally to deploy the stent while simultaneously retracting the outer shaft proximally, providing optimal control over the deployment process without mechanical coupling constraints.
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
Enables precise and accurate stent placement in various anatomical locations, reducing the risk of understenting, overstenting, or inaccurate deployment, and simplifies procedures by allowing deployment from either end, improving clinical outcomes in complex vascular interventions.
Implementation Method 1
Self-expanding stents are made from a material that is resiliently biased to return to a pre-set shape
Implementation Method 2
These materials may include superelastic and shape memory materials that can expand to an implanted configuration upon delivery or through a change in temperature
Implementation Method 3
These materials may include superelastic and shape memory materials that can expand to an implanted configuration
Data Source
AI summary
A bi-directional stent delivery system includes an inner elongate shaft, a radially expandable prosthesis disposed over the inner elongate shaft, an outer elongate shaft, and a shuttle sheath disposed over the radially expandable prosthesis. The distal portion of the inner shaft is releasably coupled to the distal portion of the shuttle sheath, and the distal portion of the outer shaft is releasably coupled the proximal portion of the shuttle sheath. Distal advancement of the inner shaft advances the shuttle sheath distally when the outer shaft is uncoupled from the shuttle sheath, thereby allowing the prosthesis to radially expand from a proximal end to a distal end. Proximal retraction of the outer shaft retracts the shuttle sheath proximally when the inner shaft is uncoupled from the shuttle sheath, thereby allowing the prosthesis to radially expand from a distal end to a proximal end thereof.