Sheathless Stent Delivery Shaft for Tortuous Catheter Navigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional delivery systems for self-expanding stents are cumbersome, limiting physician flexibility in selecting catheter type and size, and often require multiple components, making navigation through tortuous anatomy challenging.
Innovation Solution
A tubular shaft with relief cuts and apertures for stent engagement, allowing for stent delivery over a guidewire without a sheath, enabling selection of any catheter and maintaining guidewire access, with features like apertures and radiopaque markers for precise implant placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional delivery systems use multiple components (sheath, pusher wire, delivery catheter), then the stent can be delivered, but the system becomes cumbersome and navigation through tortuous anatomy becomes challenging
Solution Approach 1:
The patent combines the stent, delivery catheter, and pusher wire into a single integrated delivery system. The stent is crimped directly onto the delivery catheter shaft, eliminating the need for separate sheaths and pusher wires. This unified structure simplifies navigation through tortuous anatomy while maintaining all necessary delivery functions.
Solution Approach 2:
The delivery catheter is designed to perform multiple functions: it serves as the delivery vehicle for the stent, the pusher mechanism, and the structural support element. The single structure replaces multiple specialized components, reducing overall system complexity while maintaining operational capability.
2Adaptability or versatility
If conventional systems use sheaths to contain stents, then stent delivery is achieved, but physician flexibility in selecting catheter type and size is limited
Solution Approach 1:
The delivery catheter is designed as a universal platform that can accommodate different stent sizes and types. By eliminating the constraint of fixed sheath-stent sizing relationships, physicians can select from a broader range of catheter types and sizes to match specific patient anatomy and clinical requirements.
Solution Approach 2:
The system transitions from a fixed, pre-assembled sheath-stent configuration to a dynamic delivery mechanism where the stent is mounted on the catheter shaft itself. This allows for greater adaptability in catheter selection and configuration based on individual patient needs.
3Strength
If stents are crimped onto rigid delivery systems, then structural support is maintained, but flexibility for navigation is reduced
Solution Approach 1:
The delivery catheter incorporates varying degrees of flexibility along its length, with the distal portion being more flexible for navigation through tortuous anatomy while the proximal portion maintains sufficient rigidity for pushability and stent deployment. This gradient in mechanical properties allows simultaneous achievement of navigation flexibility and structural support.
Data Source
AI summary
The devices and methods described herein are for use with conventional catheters and guidewires. Access can be maintained with the catheter and/or guidewire and the device can be backloaded onto the guidewire and into the catheter to be advanced to a target. The devices can include a tubular shaft having a lumen for receiving a guidewire; at least one aperture for receiving a feature of an implant positioned on the tubular shaft; and a plurality of relief cuts. The outer diameter of the tubular shaft is sized relative to an inner diameter of a catheter for receiving the tubular shaft, such that a sheath is not positionable in a lumen of the catheter when the tubular shaft is in the lumen of the catheter. The tubular shaft can be axially displaced in the lumen of the catheter to advance or retract the implant positioned on the tubular shaft.