Sheathless Transradial Dilator for Reduced Arterial Trauma
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Solution Overview
Problem
Transradial catheterization is limited by the small diameter of the radial artery, leading to complications such as spasm, pain, and iatrogenic occlusion, and existing sheathless systems are costly and restrictive in terms of guide catheter size and shape options.
Innovation Solution
A dilator system with a maximal outer diameter distal portion and a reduced profile proximal portion allows for sheathless access, enabling the use of larger diameter guide catheters and facilitating guide catheter exchange without the need for a sheath, allowing any guide catheter size, shape, or manufacturer to be used.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a sheath is used in transradial catheterization, then guide catheter delivery is facilitated, but the entry hole diameter increases causing arterial spasm, pain, and occlusion
Solution Approach 1:
The patent removes the sheath component from the catheterization system, allowing the guide catheter to be delivered directly through the punctured radial artery without being enclosed in a sheath. This extraction of the sheath eliminates the size mismatch problem where the sheath outer diameter exceeded the radial artery inner diameter, thereby preventing arterial spasm, pain, and occlusion while still enabling guide catheter delivery.
Solution Approach 2:
Instead of delivering the guide catheter through a sheath (traditional approach), the patent inverts the sequence by first delivering the guide catheter directly through the artery and then removing it. This reversal of the traditional sheath-catheter delivery sequence allows for smaller entry hole diameter while maintaining guide catheter delivery capability.
2Ease of operation
If a 6 French sheath is used for radial access, then guide catheter delivery is enabled, but guide catheter size is limited and procedural complexity increases
Solution Approach 1:
By removing the sheath constraint, the patent enables the use of guide catheters with larger diameters and various configurations that would not fit through a 6 French sheath. This extraction eliminates the size limitation imposed by the sheath, allowing operators to select guide catheters based on procedural needs rather than sheath compatibility.
Solution Approach 2:
The sheathless system provides universal compatibility with guide catheters of different sizes, shapes, and manufacturers. Without the sheath's dimensional constraints, the system can accommodate a wider range of guide catheter designs, making it adaptable to various procedural requirements and enhancing overall system versatility.
3Object-affected harmful factors
If current sheathless systems are used, then entry hole size is reduced, but system cost increases and guide catheter choices are limited
Solution Approach 1:
The patent employs a simple, disposable puncture needle and guide catheter system without expensive reusable sheaths or complex sheathless access devices. The use of inexpensive, single-use components achieves the sheathless benefit of reduced arterial trauma while significantly lowering procedural costs compared to commercial sheathless systems.
Solution Approach 2:
Instead of using specialized expensive sheathless access devices, the patent inverts the traditional approach by simply omitting the sheath component entirely. This minimalist inversion achieves the same protective effect against arterial trauma as complex sheathless systems but at a fraction of the cost, using only basic puncture and catheterization tools.
4Ease of operation
If the radial artery is accessed with a device larger than the artery diameter, then guide catheter delivery is achieved, but arterial irritation and spasm increase
Solution Approach 1:
The patent removes the sheath that caused the size mismatch between the access device and radial artery. By extracting the sheath component, the guide catheter itself becomes the access device, allowing its diameter to closely match the radial artery inner diameter. This eliminates the excessive stretching and irritation caused by larger sheaths while maintaining guide catheter delivery capability.
Data Source
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AI summary
A dilator (10) for sheathless access to a vessel of a patient, having a distal portion (14) with a maximal outer diameter that extends from a distal end (12) to a guidewire exit port (16) and a proximal portion (18) with a reduced profile that extends from the guidewire exit port to the proximal end (20) and a lumen (22) that extends between the distal end and the guidewire exit port. A first guidewire (42) may be positioned within the vessel and the dilator advanced over the guidewire. A guide catheter may then be advanced over the dilator.