Bifurcated Stent Delivery With Nested Shafts
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Solution Overview
Problem
Existing methods for restoring blood flow in peripheral artery disease, such as ablating occlusions or creating fistulas, face challenges in accurately positioning and maintaining bifurcated stents within blood vessels, particularly due to differences in vein and artery diameters and the type of anastomosis created, which can divert blood flow and occlude the target artery.
Innovation Solution
A bifurcated stent system with a main and side portion, supported by inner and outer shafts, is designed for precise deployment within a blood vessel and anastomosis, utilizing a guidewire lumen and handle mechanisms for controlled expansion and positioning, ensuring effective blood flow redirection while maintaining access through sheaths and handles for manipulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a bifurcated stent is deployed to create an anastomosis between blood vessels, then blood flow is restored by bypassing occlusions, but the original blood flow inside the target artery may be occluded due to termino-terminal anastomosis type
Solution Approach 1:
The stent is divided into multiple segments including a main body portion and a side portion that can be deployed independently. The main body portion is deployed within the target artery to maintain patency, while the side portion extends into the anastomosis to redirect blood flow, thus preventing complete occlusion of the target artery while still restoring blood flow through the bypass channel.
2Reliability
If catheters are used to create an anastomosis between vessels of different diameters, then blood flow channel is established, but positioning accuracy deteriorates due to freedom of movement in larger veins
Solution Approach 1:
The delivery system employs a nested structure with an inner shaft containing the stent and an outer shaft that receives the inner shaft. The outer shaft provides a constrained pathway that limits catheter movement and improves positioning accuracy, while still allowing the stent to be deployed in vessels of different diameters. The nested configuration ensures the catheter remains stable within the larger vein while maintaining precise control over stent placement.
3Device complexity
If a single shaft system is used to deploy a bifurcated stent, then device complexity is reduced, but deployment precision deteriorates due to inability to independently position main and side portions
Solution Approach 1:
The shaft system is segmented into an inner shaft and an outer shaft that can move independently relative to each other. The inner shaft supports the main body portion of the stent while the outer shaft supports the side portion. This segmentation allows independent positioning and deployment of each stent portion, achieving precise placement in the bifurcated configuration, while the overall dual-shaft structure remains relatively simple and manageable.
Data Source
AI summary
Systems and methods for implanting a bifurcated stent comprising a main portion and a side portion within a blood vessel and an adjoining anastomosis are provided. The system includes a Y-shaped inner shaft having a first portion for supporting the main portion of the bifurcated stent and a second portion for supporting the side portion of the bifurcated stent, a first outer shaft for receiving the main portion of the bifurcated stent in a collapsed delivery state over the first portion of the inner shaft, and a second outer shaft for receiving the side portion of the bifurcated stent in a collapsed delivery state over the second portion of the inner shaft. The first and second outer shafts may be retracted relative to the bifurcated stent to deploy the bifurcated stent within the target blood vessel and adjoining anastomosis.