Balloon Catheter with Differential Compliance for Stent Flaring
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Solution Overview
Problem
Stents deployed at ostiums or bifurcations often extend into main vessels, causing difficulties in future interventions, potential damage to neighboring structures, and suboptimal lesion treatment due to lack of contact with the vessel wall.
Innovation Solution
A balloon catheter system with a first elastic membrane and a second, less elastic membrane is used to flare the stent, where the balloon is initially inflated to engage the stent and then further expanded to flare one end of the stent while maintaining the reinforced region at a constant diameter, ensuring better positioning and contact with the vessel wall.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the stent is deployed extending into the main vessel to facilitate delivery and positioning, then the stent can be easily delivered and positioned at the ostium, but future endoluminal interventions become difficult and neighboring structures may be damaged
Solution Approach 1:
The stent is pre-shaped with a flared distal end configuration before deployment. This preliminary shaping ensures that when the stent is deployed, the distal end automatically flares to engage the vessel wall at the ostium, preventing the stent from extending into the main vessel and causing damage to neighboring structures while facilitating future interventions
Solution Approach 2:
The stent has non-uniform geometry with a flared distal end and a different proximal end configuration. This local quality variation allows the distal end to specifically engage the vessel wall at the ostium for secure positioning and lesion treatment, while the proximal end maintains appropriate positioning without extending excessively into the main vessel
2Stability of the object's composition
If the stent is positioned to extend into the main vessel for secure anchoring, then the stent achieves stable positioning, but contact with the ostium wall is reduced resulting in suboptimal lesion treatment
Solution Approach 1:
The stent features a flared distal end with increased radial profile specifically designed to contact and engage the vessel wall at the ostium. This local geometric modification ensures optimal lesion treatment through direct wall contact while the overall stent positioning remains stable through the anchored flared configuration
3Productivity
If a uniform balloon expansion is used to deploy the stent, then the deployment process is simple and quick, but the stent cannot be flared to achieve proper positioning and contact with the vessel wall
Solution Approach 1:
The balloon is divided into multiple inflation zones with different compliance characteristics - a high-compliance distal segment for flaring and a low-compliance proximal segment for controlled expansion. This segmentation allows selective flaring of the distal stent end to achieve proper positioning and wall contact while maintaining deployment efficiency
Solution Approach 2:
The balloon has non-uniform wall thickness and compliance along its length, with the distal portion being more compliant to allow flaring. This local quality variation enables differential expansion where the distal stent end flares to contact the vessel wall while the proximal portion expands uniformly, achieving both positioning accuracy and efficient deployment
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
This method allows for improved positioning and contact of the stent with the vessel wall, reducing the risk of damage and enhancing lesion treatment, while facilitating easier recrossing for future interventions.
Implementation Method 1
the first membrane is formed from elastic material and the second membrane is formed from material having an elasticity equal to or less than the first membrane
Data Source
AI summary
Apparatus and methods are provided for flaring a stent deployed within a branch vessel including an ostium communicating with a main vessel, a first end of the stent extending at least partially from the branch. A catheter is provided that includes a balloon having a reinforced region adjacent an unreinforced region. When the balloon is positioned at a desired location, e.g., within a stent, prosthetic valve, or other tubular prosthesis, the balloon may be inflated to a first pressure causing the reinforced and unreinforced regions to expand substantially simultaneously. Upon inflation of the balloon beyond the first pressure, the reinforced region of the balloon remains at the first diameter and the unreinforced region continues to expand, e.g., to flare one or more ends of the prosthesis.