Multi-Stent Balloon Delivery for Bifurcation Side-Branch Access
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Solution Overview
Problem
Conventional stents face challenges in treating bifurcations due to issues such as stent jailing, plaque shifting, and obstruction of side branches, necessitating improved medical devices and methods for safer and more reliable treatment of bifurcated vessels.
Innovation Solution
A dual-catheter system with independently expandable balloons and stents is used to deliver and deploy stents in both the main and side branches of a bifurcated vessel, allowing precise alignment and expansion to support the vessel walls without obstructing the side branch, using notched stents and balloons that can be inflated sequentially or simultaneously to ensure comprehensive treatment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional stent is deployed in a bifurcated vessel to treat the main branch, then the main branch is supported and plaque is stabilized, but the stent obstructs the side branch opening causing stent jailing and limiting access for diagnostic or therapeutic devices
Solution Approach 1:
The stent is divided into multiple segments or struts with varying densities. The proximal portion has a lower strut density creating an ostium-preserving pattern that maintains side branch access, while the distal portion has higher strut density for optimal main branch support. This segmentation allows different regions of the stent to serve different functions simultaneously.
Solution Approach 2:
Different portions of the stent are designed with different local properties. The proximal section features an ostium-preserving pattern with larger inter-strut spaces to maintain side branch patency, while the distal section features a standard pattern with denser struts for effective plaque support. This local quality variation resolves the contradiction between maintaining access and providing support.
2Reliability
If balloons and stents are inflated and expanded in a bifurcation to treat lesions, then plaque is compressed and vessel support is improved, but plaque shifts to create snow plowing and new blockages
Solution Approach 1:
The ostium-preserving pattern is deployed first to establish a framework that contains plaque within the vessel wall. This preliminary action creates a structural constraint that prevents plaque from shifting distally during subsequent balloon inflation, thereby preventing snow plowing while still allowing effective lesion treatment.
Solution Approach 2:
The stent design incorporates preliminary anti-action by creating a proximal barrier structure that counteracts the natural tendency of plaque to shift distally during balloon expansion. This preliminary counter-measure prevents the harmful snow plowing effect before it can occur during the treatment process.
3Reliability
If stents are deployed to cover the entire bifurcation area including the side branch ostium, then comprehensive vessel support is achieved, but blood flow into the side branch is obstructed
Solution Approach 1:
The stent is segmented into proximal and distal portions with different strut densities. The proximal portion uses an ostium-preserving pattern with larger spaces that allow blood flow into the side branch, while the distal portion uses a standard dense pattern for comprehensive support. This segmentation enables the stent to provide comprehensive vessel support while maintaining side branch patency.
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 system effectively dilates and supports bifurcated vessels, reducing the risk of stent jailing and plaque shifting, while providing uniform scaffolding and improved clinical outcomes.
Implementation Method 1
The expandable member has a collapsed configuration and an expanded configuration. The collapsed configuration has a profile suitable for advancement through a blood vessel, and the expanded configuration has a larger profile than the collapsed configuration profile.
Data Source
AI summary
A system for treating a bifurcated vessel that includes a first delivery catheter and a second delivery catheter. The first delivery catheter carries a proximal first stent and a distal second stent. The first delivery catheter also has a first elongate shaft, a proximal first expandable member with the proximal first stent disposed thereover, and a distal second expandable member with the distal second stent disposed thereover. The proximal first expandable member and distal second expandable member are independently expandable of one another. The second delivery catheter carries a third stent. The second delivery catheter also has a second elongate shaft, and a third expandable member with the third stent disposed thereover. The third expandable member is independently expandable of the proximal first expandable member and the distal second expandable member.