Stent-Graft Perfusion Window for In Situ Fenestration
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Solution Overview
Problem
Current stent-grafts often poorly fit patient anatomy, leading to challenges in aligning fenestrations with side-branch vessels and potential occlusion of these vessels during implantation, requiring multiple surgical tools and imprecise placement.
Innovation Solution
A stent-graft design featuring a first portion that engages the vessel wall, a second portion with a smaller diameter that does not engage the wall, and a transition portion with perfusion windows for precise blood flow and visualization, allowing for in situ fenestration and precise alignment with side-branch vessels using contrast media and a fenestration device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stent-graft is implanted in a patient's abdominal aorta, then the aneurysm is treated, but blood flow to side-branch vessels (renal arteries) is occluded or blocked
Solution Approach 1:
The stent-graft is divided into multiple sections including a main body and separate side-branch components. The side-branch vessels are addressed as distinct segments that can be selectively opened or closed independently from the main aortic treatment, allowing the aneurysm to be treated while preserving side-branch perfusion through separate controllable mechanisms.
2Ease of operation
If fenestrations are manufactured a priori in stent-grafts, then side-branch vessel access is enabled, but the device fits poorly within patient anatomy due to pre-sized nature
Solution Approach 1:
The stent-graft incorporates dynamic, adjustable fenestration mechanisms that can be opened or closed after implantation. This allows the device to adapt to the patient's specific anatomy post-implantation, combining the ease of pre-formed fenestrations with the precision of customized anatomic fitting through post-deployment adjustment capabilities.
3Measurement precision
If multiple guidewires and angiographic catheters are used for alignment, then fenestration alignment with side-branch vessels is achieved, but surgical complexity and equipment quantity increase
Solution Approach 1:
The stent-graft integrates alignment and positioning functions directly into the device structure itself, combining what were previously separate tools (guidewires, catheters, and the stent-graft) into a single integrated system. This reduces the number of separate surgical tools needed while maintaining precise alignment capabilities through built-in positioning features.
4Manufacturing precision
If stent-grafts are made with smaller diameter second portion, then device flexibility and placement precision are improved, but blood flow capacity is reduced
Solution Approach 1:
The stent-graft employs different diameters in different sections optimized for their specific functions: a smaller diameter in the precision placement zone for accurate positioning, and larger diameter sections in the main body and side-branches for adequate blood flow capacity. This local differentiation of dimensions allows both precise placement and sufficient flow capacity to coexist.
Data Source
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AI summary
The present disclosure includes a stent-graft comprising a first portion that is configured to engage a vessel wall, a second portion that is configured not to engage the vessel wall, and a perfusion window that is configured to permit blood flow. The stent-graft may further comprise a transition portion between the first portion and the second portion, and the perfusion window may be formed in the first portion, the second portion, and/or the transition portion. In a variety of embodiments, one of the first and the second portion may have a smaller diameter than the other. Similarly, in a variety of embodiments, the transition portion may be frustoconically shaped.