Branching Stent-Graft Mechanical Interlock to Prevent Migration
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Solution Overview
Problem
Conventional stent-grafts in complex anatomies face issues with interference fit connections that can fail over time, leading to migration and complications such as endoleaks and vascular obstruction.
Innovation Solution
A modular assembly of stent-grafts featuring a first stent-graft with a body and waist portion of different diameters, and a second stent-graft with a captured proximal portion that forms a mechanical interlock, preventing migration by creating a higher joint strength through differential diameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If an interference fit connection is used to connect stent-grafts, then the connection can be established, but the connection can fail over time leading to migration
Solution Approach 1:
The connection interface is segmented into distinct functional zones: an interference fit zone for initial connection and a mechanical interlock zone with protrusions and recesses for long-term stability. This segmentation allows each zone to perform its specific function optimally without compromising the other.
Solution Approach 2:
The mechanical interlock features (protrusions and recesses) are pre-formed on the stent-grafts before deployment. When the stent-grafts are connected, these pre-formed features automatically engage to create the mechanical interlock, preventing migration without requiring additional steps or components.
2Reliability
If a mechanical interlock is created with differential diameters, then migration is prevented, but the device complexity increases
Solution Approach 1:
The differential diameter and mechanical interlock features are implemented only at the specific connection interface where needed, rather than throughout the entire stent-graft structure. This localized approach provides the necessary anti-migration capability while minimizing overall device complexity.
Solution Approach 2:
The mechanical interlock features are integrated directly into the stent-graft structures themselves, merging the connection function with the existing stent-graft anatomy. This eliminates the need for separate connection components or additional assembly steps, reducing overall device complexity.
Data Source
AI summary
The techniques of this disclosure generally relate to a modular assembly including first and second stent-grafts. The first stent-graft includes a body portion having a first diameter and a waist portion having a second diameter less than the first diameter. The waist portion is at a distal end of the first stent-graft. The second stent-graft includes a captured proximal portion configured to be located within the first stent-graft. The captured proximal portion includes a seated portion configured to be located proximal to the waist portion. The seated portion has a third diameter greater than the second diameter to form a mechanical interlock between the first stent-graft and the second stent-graft.