Bifurcated Stent Graft Layout for Small-Catheter Aneurysm Repair
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Solution Overview
Problem
Current medical devices for treating vascular abnormalities, such as aortic aneurysms, face challenges in delivering and anchoring stent grafts within bifurcated lumens without blocking blood flow or causing trauma to vascular tissue, particularly due to the size and flexibility limitations of existing delivery catheters.
Innovation Solution
A stent graft design featuring a tubular structure with an opening in its sidewall, configured to expand and self-deploy within bifurcated lumens, utilizing braided strands or occlusive materials for fixation and thrombus formation, allowing for coaxial alignment and reduced delivery profile, thereby minimizing tissue trauma and facilitating access to smaller vessels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a traditional bifurcated stent graft is delivered through one iliac artery, then the device can be deployed to treat the aneurysm, but the delivery catheter size increases causing trauma to vascular tissue and reducing flexibility for access to smaller vessels
Solution Approach 1:
The stent graft is divided into two separate tubular portions (first and second portions) that can be delivered independently through separate delivery catheters. This segmentation allows each catheter to be smaller in size, reducing trauma to the vascular tissue while still achieving the therapeutic effect of excluding the aneurysm from both iliac artery access points.
Solution Approach 2:
Each tubular portion of the stent graft is nested within its own delivery catheter in a coaxial arrangement. The first tubular portion is constrained within a first delivery catheter, and the second tubular portion is constrained within a second delivery catheter, allowing for compact delivery while maintaining the ability to deploy larger stent graft structures at the target site.
2Ease of operation
If the delivery catheter is made smaller to reduce tissue trauma, then less trauma occurs and access to smaller vessels is improved, but the ability to manipulate and position the catheter within the lumen is reduced
Solution Approach 1:
By dividing the delivery system into two separate delivery catheters, each catheter can be optimized for its specific function and size requirements. The smaller catheter size reduces trauma while the segmented design allows for independent manipulation and positioning of each tubular portion, maintaining ease of operation despite the reduced individual catheter size.
3Reliability
If a stent graft is deployed to exclude an aneurysm, then the aneurysm is protected from pressure and flow, but blood flow through branch vessels such as renal arteries may be blocked
Solution Approach 1:
The stent graft is segmented into two separate tubular portions delivered from different directions (each iliac artery). This allows the main body of the stent graft to be positioned downstream of the renal arteries, excluding the aneurysm from pressure and flow, while the separate delivery approach enables precise positioning that preserves patency of the renal arteries and other branch vessels.
Solution Approach 2:
Instead of delivering a single large bifurcated stent graft from one iliac artery that risks blocking renal arteries, the approach is inverted by delivering two separate tubular portions from each iliac artery independently. This reverse approach allows for better control of stent graft positioning relative to branch vessels, maintaining aneurysm exclusion while preserving blood flow through renal and other branch arteries.
4Ease of operation
If a bifurcated stent graft is delivered through one iliac artery, then the procedure can be performed, but the positioning of tubular portions into respective iliac arteries becomes complicated
Solution Approach 1:
The delivery system is segmented into two independent delivery catheters, each responsible for delivering one tubular portion into its corresponding iliac artery. This segmentation simplifies the positioning procedure compared to maneuvering a single complex bifurcated stent graft, as each catheter can be independently guided and positioned without interfering with the other, reducing overall delivery procedure complexity.
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
The stent graft effectively excludes aneurysms by directing blood flow into separate lumens, ensuring adequate fixation without blocking renal arteries, and can be delivered through smaller catheters, reducing trauma and enabling treatment of harder-to-reach anatomical sites.
Implementation Method 1
The first tubular structure comprises an expanded preset configuration and is configured to be constrained to a smaller diameter than the expanded preset configuration and return to the expanded preset configuration when unconstrained
Data Source
AI summary
Embodiments of the present invention provide medical devices and methods for treating a target site within the body. For example, one embodiment provides a stent graft for treating a target site proximate to a bifurcated lumen, wherein the stent graft includes a first tubular structure having proximal and distal ends and a side wall extending therebetween. The first tubular structure includes an opening defined within the side wall and is configured to define a first portion having first and second ends and a second portion having first and second ends. The opening corresponds to the first ends of the first and second portions and the second ends of the first and second portions respectively correspond to the proximal and distal ends of the first tubular structure, and at least a portion of the first and second portions are configured to be positioned within respective branches of a bifurcated lumen.