Bifurcated Endoluminal Prosthesis Sealing Stent Design
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Solution Overview
Problem
Existing endoluminal prostheses for damaged vessels face challenges in ensuring complete sealing and stability, particularly at bifurcations, due to potential leaks and module misalignment, which can exacerbate the treated condition.
Innovation Solution
A bifurcated endoluminal prosthesis system with a secondary delivery device that deploys a second leg from a predeployment configuration, where it is inverted within the first leg, to a deployed configuration, using a sealing stent that is unattached at one end to the graft body, ensuring secure positioning and sealing within the vascular wall.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a modular prosthetic system is used with multiple modules assembled in situ, then the prosthesis can be adapted to complex vascular geometries including bifurcations, but the risk of leaks and module misalignment increases
Solution Approach 1:
The second leg of the bifurcated prosthesis is inverted and nested within the first leg during delivery, with both legs contained within the delivery catheter. This nesting approach allows complex bifurcated geometry to be delivered through a single catheter while maintaining precise control over module positioning, thereby adapting to vascular bifurcations without increasing leak risk.
Solution Approach 2:
The second leg is pre-assembled and inverted within the delivery catheter before insertion into the patient's body. This preliminary configuration ensures that the modular components are precisely positioned and sealed before deployment, preventing misalignment and leaks that could occur with in-situ assembly of multiple modules.
2Ease of operation
If the second leg is inverted within the first leg during delivery, then the prosthesis can be delivered through a single catheter, but the deployment complexity increases
Solution Approach 1:
The second leg is inverted (turned inside out) during assembly within the delivery catheter, with its distal end positioned near the proximal end of the first leg. This inversion allows both legs to be contained within the single catheter for simplified delivery, while the inversion itself becomes the key mechanism for controlled deployment - pushing the second leg causes it to evert and expand into its functional configuration.
3Reliability
If a sealing stent is used to hold the tubular graft in position, then radial pressure against the vessel wall improves sealing, but the risk of aggravating the treated condition through excessive pressure increases
Solution Approach 1:
The sealing stent is designed with varying radial stiffness along its length, with greater rigidity at the ends for anchoring and sealing, and reduced rigidity in the middle section to minimize stress on the vessel wall. This local differentiation provides effective sealing at critical interfaces while reducing harmful hemodynamic stress in the treated vessel segment.
Solution Approach 2:
The stent's radial force characteristics are modified by changing its structural parameters - using different wire diameters, braid patterns, or cell sizes in different sections. This allows the stent to exert sufficient radial pressure for sealing at the graft-vessel interface while maintaining lower pressure in the central portion to avoid aggravating the treated vascular condition.
Data Source
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AI summary
A system for treating a body vessel may include a delivery device and a prosthesis retained on the delivery device. The prosthesis may include a main body and first and second legs each extending from the main body. The main body may include a lumen, and the first leg may include a lumen in fluid communication with the lumen of the main body. The second leg may include a tubular graft body and a stent attached to the graft body. The prosthesis may have a predeployment configuration in which the graft body of the second leg is inverted into and positioned within the lumen of the first leg, and the stent is positioned outside of the inverted graft body. The prosthesis may have a deployed configuration in which the second leg extends outward from the main body, and the stent is positioned within a lumen of the graft body.