Nested Stent Graft Leg Design for Aortic Bifurcation Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current bifurcated modular prostheses face challenges in deployment, particularly at the iliac bifurcation and thoracic arch, where space constraints and branch arteries complicate the placement and sealing of stent grafts, affecting blood flow and occlusion of essential arteries.
Innovation Solution
A stent graft design featuring fenestrations and tubes extending from these openings, allowing for deployment of extension legs into branch vessels, with angled or curved configurations to facilitate sealing and blood flow, and the use of self-expanding Z stents for a secure fit, along with flared guides for easier access and placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a traditional bifurcated modular prosthesis is deployed at the iliac bifurcation, then the prosthesis can provide structural support, but there is insufficient space for overlap of the extension leg with the short leg in the aorta
Solution Approach 1:
The invention places the second leg extending into the body portion as a nested structure within the aortic stent graft. The second leg is positioned inside the body portion, creating a nested configuration that maximizes space utilization. This allows the extension leg to be inserted through the contra-lateral iliac artery and overlap sufficiently with the first leg within the constrained aortic space, while maintaining reliable sealing at the aneurysm site.
2Ease of operation
If a stent graft is deployed into the thoracic arch with side arms extending into branch arteries, then blood flow to branch arteries can be maintained, but it is difficult to deploy the stent graft properly
Solution Approach 1:
The invention divides the stent graft into segmented components: a body portion with fenestrations and multiple separate leg portions that can be deployed independently. The second leg extending into the body portion creates additional segmentation that allows for staged deployment. This segmentation simplifies the deployment process in the thoracic arch by allowing the main body to be positioned first, followed by selective extension of legs into branch arteries, thereby maintaining ease of operation while ensuring reliable blood flow to all branch vessels.
3Manufacturing precision
If the prosthesis is placed close to the aortic bifurcation, then optimal positioning is achieved, but there is insufficient space for extension leg overlap
Solution Approach 1:
The invention utilizes the radial dimension by extending the second leg into the body portion, creating a three-dimensional configuration. Instead of only extending legs in the longitudinal direction, the second leg projects inward into the aortic stent graft body, effectively using the radial space. This dimensional change allows the prosthesis to be positioned optimally close to the aortic bifurcation while still providing sufficient overlap space for extension legs within the available volume.
4Volume of moving object
If graft needs to be placed within another already placed graft, then space constraints are addressed, but there is only a short length of grafted aorta to work with
Solution Approach 1:
The invention employs nested doll configuration where the second leg is placed within the body portion of the aortic stent graft, and the extension leg is inserted through the contra-lateral iliac artery and positioned within the second leg. This multi-level nesting allows the graft to be placed within the already deployed aortic graft, maximizing utilization of the short available aortic length while managing the complexity through a systematic nested structure that provides clear deployment pathways.
Data Source
AI summary
A stent graft has a tubular wall (1) defining a main lumen with at least one fenestration (15) in the wall. A tube (17) extends from the fenestration into the main lumen and is in fluid communication with the main lumen. An extension leg stent graft can be deployed from a branch vessel into the fenestration to seal into the tube. A flared guide (89) associated with the fenestration can be provided interiorly or exteriorly. There is also disclosed a bifurcated intraluminal prosthesis having a body (1), a first leg (7) and a second leg (17), the first leg extending from the body and the second leg extending into the body.