Flared Stent Delivery via Dual-Balloon Expansion
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Solution Overview
Problem
Existing stent delivery technologies face challenges in effectively deploying flared stents at ostia, particularly at bifurcations, due to difficulties in achieving proper expansion and maintaining ostium dilation.
Innovation Solution
A stent design with a tubular member featuring a first end portion that flares outwardly during expansion, connected to a second portion by flexible connectors, and an expandable member with independent balloons for controlled expansion, allowing for precise deployment and enhanced radial strength to maintain ostium dilation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional stent is deployed at an ostium, then the stent can be delivered to the target location, but the stent cannot achieve proper expansion or maintain ostium dilation due to insufficient radial strength and inability to accommodate various ostial shapes
Solution Approach 1:
The stent is divided into multiple portions including a first portion with higher radial strength and a second portion with lower radial strength, allowing differential expansion characteristics at different locations to maintain ostium dilation while accommodating vessel geometry
Solution Approach 2:
Different portions of the stent are assigned different radial strength properties - the first portion has higher radial strength to maintain ostium dilation, while the second portion has lower radial strength to conform to the vessel, creating localized functional optimization
2Adaptability or versatility
If a flared stent design is used to accommodate ostial shapes, then the stent can adapt to various geometries, but the delivery system becomes more complex requiring controlled expansion mechanisms
Solution Approach 1:
The stent transitions from a compressed delivery state through an intermediate flared state to a fully expanded state, with the delivery system providing controlled expansion through balloon inflation to achieve the desired flared configuration for ostial accommodation
Solution Approach 2:
The stent is pre-shaped with a flared configuration design that will be activated during deployment, allowing it to naturally adapt to ostial geometries without requiring complex real-time adjustment mechanisms during the procedure
3Strength
If the entire stent is expanded to maximum size, then the stent provides maximum radial strength, but the stent cannot navigate through the vessel or be delivered to the target location
Solution Approach 1:
The stent dynamically changes its radial profile during delivery and deployment - starting in a low-profile compressed state for navigation, then expanding to maximum size at the target location to provide the necessary radial strength for ostium maintenance
4Reliability
If a single-balloon expansion system is used, then the delivery system is simpler, but the stent cannot achieve controlled differential expansion to maintain ostium dilation
Solution Approach 1:
The expansion system is segmented into multiple balloons that can be inflated independently or in sequence, allowing controlled differential expansion of different stent portions to maintain ostium dilation while accommodating vessel geometry
Solution Approach 2:
The multi-balloon system is pre-positioned on the stent during manufacturing, with each balloon corresponding to a specific stent portion, enabling controlled sequential or simultaneous inflation to achieve the desired expansion pattern for ostium maintenance
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 stent design enables successful deployment and maintenance of ostium dilation, providing enhanced radial strength and flexibility to accommodate various ostial shapes and sizes, thereby improving treatment efficacy at bifurcations.
Implementation Method 1
the stent includes a first end portion configured to flare outwardly when the stent is expanded from the contracted condition to an intermediate flared condition, and a second portion adjacent the first portion configured to expand when the stent is expanded from the flared condition to a fully deployed condition
Data Source
AI summary
Flared stents are disclosed, and apparatus and methods for delivering such stents into a bifurcation between a main vessel and a branch vessel. The stent includes a first tubular portion a second flaring portion that may be flared radially outwardly to contact the ostium. The stent may include variable mechanical properties along its length. The stent may be delivered using a catheter including proximal and distal ends, the stent overlying first and second balloons on the distal end. During use, the catheter is advanced through an ostium into the branch to place the stent within the branch. The first balloon is expanded to flare the stent to contact a wall of the ostium, thereby causing the stent to migrate partially into the ostium. The second balloon is expanded to fully expand the stent within the ostium and branch.