Bifurcation Stent Alignment via Interdigitating Axial and Lateral Elements
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Solution Overview
Problem
Conventional stent technologies face challenges in effectively treating bifurcated vessels due to difficulties in aligning side branch and main branch stents, leading to issues like in-stent restenosis, plaque shifting, and limited access for post-operative treatments, particularly at vessel bifurcations where current stent designs compromise between coverage and access.
Innovation Solution
A system comprising two radially expandable stents with interdigitating axial and lateral elements, allowing for precise alignment and simultaneous expansion to ensure uniform scaffolding at bifurcations, along with a catheter system that includes radiopaque markers for alignment and a delivery mechanism to facilitate accurate placement and expansion of stents in both the main and side branches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional stent designs with straight tubular cellular structure are used, then manufacturing simplicity is maintained, but alignment precision at bifurcations deteriorates
Solution Approach 1:
The stent is divided into multiple modular units (first stent unit, second stent unit, third stent unit) with distinct functions. The first unit provides coverage in the main vessel, while the second and third units are designed to align with and treat the side branch, allowing each segment to be optimized for its specific location and function.
Solution Approach 2:
The stent design transitions from symmetric conventional structures to asymmetric configurations where the second and third stent units have different orientations and functions. The second unit aligns with the side branch at a specific angle, creating an asymmetric structure that enables precise alignment at the bifurcation while maintaining manufacturing feasibility.
2Reliability
If stent cell structure size is minimized to promote coverage, then vessel wall support is improved, but access to daughter vessels deteriorates
Solution Approach 1:
The stent system separates the coverage function (first stent unit with minimized cell structure) from the access function (second and third stent units with larger cell structures). This segmentation allows the main vessel to receive optimal support while the side branch maintains accessibility for post-operative treatments.
Solution Approach 2:
Different regions of the stent system have different cell structure characteristics optimized for their specific functions. The first stent unit has minimized cell structure for maximum coverage and support in the main vessel, while the second and third units have larger cell structures in the side branch region to facilitate access and reduce jailing risk.
3Ease of operation
If conventional stent deployment is used, then procedural simplicity is maintained, but alignment accuracy at bifurcations deteriorates
Solution Approach 1:
The stent system is pre-configured with radiopaque markers positioned at specific locations (proximal and distal ends of each stent unit) that enable alignment to be achieved through simple visual registration during deployment. This preliminary positioning feature allows accurate alignment without complex deployment procedures.
Solution Approach 2:
Radiopaque markers are incorporated into the stent design to provide visual indicators for alignment. These markers (which appear as distinct radiopaque features under fluoroscopy) enable the operator to visually confirm proper alignment of the stent units with the bifurcation anatomy, transforming an alignment task into a simple visual registration process.
4Device complexity
If single stent design is used, then device complexity is reduced, but treatment effectiveness at bifurcations deteriorates
Solution Approach 1:
The treatment system is segmented into multiple stent units deployed in a coordinated sequence. The first stent unit is deployed in the main vessel, followed by the second and third units in the side branch. This segmentation allows each unit to be optimized for its specific location while maintaining overall treatment effectiveness.
Solution Approach 2:
Multiple stent units with different functions are merged into a coordinated treatment system. The first unit provides main vessel coverage, while the second and third units provide side branch treatment with interdigitating elements. Together, they create a comprehensive solution that addresses both coverage and access requirements at the bifurcation.
Data Source
AI summary
A system for treating a bifurcation includes a first radially expandable stent and a second radially expandable stent. The first stent has a side hole and a plurality of lateral elements extending from the side hole. The second stent has a plurality of axial elements extending away from the proximal end of the second stent. The axial elements of the second stent interdigitate with the lateral elements of the first stent when both stents have been expanded.