Selective Stent Crimping for Bifurcation Access
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Solution Overview
Problem
Conventional stent technology is inadequate for treating bifurcated vessels due to issues such as impaired blood flow, difficulty in accessing daughter vessels, and high rates of in-stent restenosis, particularly at vessel bifurcations, where existing stents often compromise between coverage and access, leading to complications like plaque shifting and restenosis.
Innovation Solution
A method and system for delivering stents to bifurcated vessels involving non-uniform crimping of stents onto expandable members of delivery catheters, allowing for secure placement and expansion of stents in both the mother and daughter vessels, with the option of therapeutic agent coating to inhibit restenosis, and a dual-catheter system that enables independent expansion and positioning of stents to optimize vessel support and blood flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stent is uniformly crimped onto an expandable member, then the stent is securely held during delivery, but access to daughter vessels at bifurcations is obstructed
Solution Approach 1:
The stent is crimped with different compression levels at different locations: uniformly crimped in the distal portion for securement, and partially uncrimped in the proximal portion to allow daughter vessel access. This local variation in crimping quality resolves the contradiction between secure delivery and procedural access.
Solution Approach 2:
The stent is divided into functionally distinct segments: a distal segment that is fully crimped for secure attachment to the delivery catheter, and a proximal segment that is partially uncrimped to facilitate daughter vessel intervention. This segmentation allows each portion to fulfill its specific function without compromising the other.
2Reliability
If the cell structure size of the stent is minimized to promote coverage, then tissue prolapse is prevented, but access to daughter vessels is reduced
Solution Approach 1:
The stent features locally varied cell structure sizes: smaller cells in the distal portion for optimal vessel wall coverage and support, and larger cells in the proximal portion for enhanced daughter vessel accessibility. This local differentiation resolves the coverage-access contradiction.
Solution Approach 2:
The stent is segmented into a distal coverage-optimized section with minimized cell size and a proximal access-optimized section with maximized cell size, allowing each region to be tailored to its specific functional requirements.
3Ease of manufacture
If a regular stent design is used, then manufacturing is simplified, but the ability to treat both mother and daughter vessels is compromised
Solution Approach 1:
The stent incorporates a dynamically adjustable crimping state: fully crimped for delivery stability, then selectively uncrimped at the proximal portion to enable daughter vessel access. This dynamic configuration allows a single stent design to adapt to multiple treatment requirements.
Solution Approach 2:
The stent is designed as a multi-functional device that can simultaneously provide mother vessel support through its distal crimped portion and daughter vessel access through its proximal uncrimped portion, eliminating the need for separate devices for each vessel segment.
Data Source
AI summary
Methods for crimping a stent on an expandable member of a delivery catheter, and devices and methods for treating a bifurcation are disclosed. A method for crimping includes positioning a stent having a first portion and a second portion over the expandable member, and non-uniformly crimping the stent to the expandable member. The method can include routing an elongate shaft under the second portion of the stent and through the side hole so as to be routed external to the first portion. The stent second portion can be crimped so that the elongate shaft can be slidably disposed relative to the stent second portion prior to deployment of the stent.