Multi-leaflet Coupling for Stent-Graft Branch Vessel Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current stent-grafts face challenges in effectively sealing and directing blood flow from the main aorta to branch vessels, particularly at aneurysm locations near vessel bifurcations, leading to potential blood leakage and impaired flow due to fenestrations that do not form a tight seal and branch stent-graft connections that are difficult to establish.
Innovation Solution
A multi-leaflet coupling system is integrated into the stent-graft, featuring a tubular body with overlapping leaflets that expand radially to form a seal on the branch vessel, allowing for secure blood flow and accommodating varying branch vessel sizes, while maintaining a conformable and leak-resistant connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If fenestrations are used in main vessel stent-grafts to accommodate branch vessels, then branch vessel access is enabled, but blood leakage occurs between the graft material and vessel wall
Solution Approach 1:
The coupling device is divided into multiple leaflets (typically three) that can independently conform to the branch vessel wall, creating multiple sealing surfaces rather than relying on a single fenestration opening. Each leaflet acts as a separate sealing element that can be adjusted to match the vessel geometry.
Solution Approach 2:
The leaflets are designed to be flexible and dynamic, allowing them to move from a compressed delivery state to an expanded deployed state where they conform to the branch vessel. This dynamic adaptation enables the coupling device to maintain sealing contact with vessels of varying sizes and shapes.
2Adaptability or versatility
If branch stent-grafts are connected to main graft in situ, then branch vessel coverage is achieved, but the connection process is difficult and prone to leakage
Solution Approach 1:
The coupling device is designed to self-seal and self-position within the branch vessel. Once deployed, the leaflets automatically conform to the vessel wall and create a seal without requiring additional manual intervention or complex connection procedures. The device performs its own sealing function through its inherent design.
Solution Approach 2:
The coupling device is nested within the main stent-graft structure during delivery, and the branch stent-graft is nested within the coupling device. This nested configuration simplifies the overall assembly and deployment process, allowing components to be delivered through a single access point and self-assemble at the target site.
3Reliability
If stent-graft is deployed to seal against aorta wall, then aneurysm exclusion is achieved, but critical branch arteries may be covered or occluded
Solution Approach 1:
The coupling device creates localized openings in the stent-graft structure at specific locations where branch vessels need to be preserved. Rather than using a uniform sealed structure, the device introduces targeted fenestrations with couplings only where branch artery access is required, maintaining sealing elsewhere while preserving critical blood flow paths.
Data Source
AI summary
A prosthesis includes a tubular body of a graft material, a plurality of stents coupled to the tubular body, and a coupling. The coupling has a plurality of overlapping leaflets successively coupled to the tubular body around an opening formed in the graft material. The leaflets in a non-deployed configuration lay flush with the graft material of the tubular body and partially cover the opening, and the leaflets in a deployed configuration extend radially outward from the graft material of the tubular body. Delivery and deployment of a branch vessel prosthesis through the opening causes the leaflets to transform from the non-deployed configuration to the deployed configuration, and causes a diameter or width of a passageway defined by the leaflets to increase. Leaflet material properties, as well as size, shape, and sewing patterns on adjacent leaflets may be varied in order to vary the flexibility and/or orientation of the coupling.