Multi-Branched Stent Graft Alignment Using an In-Line Mandrel
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Solution Overview
Problem
Current endovascular stent grafts are limited in treating complex aortic aneurysms due to anatomical constraints such as short or angulated necks and involvement of visceral and renal arteries, leading to challenges in precise design and implantation, with fenestrated stent grafts being prone to misalignment and space limitations.
Innovation Solution
The development of multi-branched stent grafts using an in-line mandrel for custom formation, which includes a cylindrical body with a tapered portion and holes for attaching branch stent grafts, allowing for flexible positioning and easier navigation through catheters, providing longer attachment sites and reducing misalignment issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If fenestrated stent grafts are used to treat complex aortic aneurysms, then treatment capability is improved, but misalignment and space limitations occur
Solution Approach 1:
Branch stent grafts are pre-formed and attached to the main body at predetermined locations before implantation. The mandrel system pre-establishes hole positions and branch orientations, ensuring proper alignment is achieved in advance rather than requiring precise alignment during the complex implantation procedure.
Solution Approach 2:
A mandrel system serves as an intermediary tool during the attachment process. The mandrel provides a physical template that guides hole formation and branch positioning, acting as a mediator between the design specifications and the actual manufacturing process to ensure precise alignment without requiring complex real-time adjustment during implantation.
2Manufacturing precision
If custom-formed multi-branched stent grafts are created using an in-line mandrel, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The mandrel is segmented into distinct functional portions: a substantially cylindrical body for the main graft, a tapered portion for hole formation and branch attachment, and a distal portion for additional positioning. This segmentation allows each portion to be optimized for its specific function while maintaining overall system manageability.
Solution Approach 2:
The mandrel structure serves multiple functions simultaneously: it provides a template for hole positioning, guides branch attachment, defines graft geometry, and facilitates catheter navigation. By consolidating these functions into a single multi-functional device, the overall system complexity is managed despite the increased precision capabilities.
3Measurement precision
If branch stent grafts are attached at predetermined locations using a mandrel, then alignment accuracy is improved, but manufacturing time increases
Solution Approach 1:
All alignment-critical features are established in advance during manufacturing. Holes are formed at precise predetermined locations while the mandrel is in place, and branch stent grafts are attached during the same manufacturing sequence. This preliminary establishment of alignment features eliminates the need for time-consuming alignment adjustments during implantation procedures.
Data Source
AI summary
Described are stent grafts with at least on branch and mandrels used to form the stent grafts. Methods of making and using them are also described.