Deflectable Tip Catheter for Chronic Total Occlusion Crossing
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Solution Overview
Problem
Chronic total occlusions in blood vessels are difficult to cross due to guidewire rigidity and orientation issues, leading to lower success rates and increased procedural complexity, especially in coronary CTOs, as conventional guidewires often buckle or perforate the vessel.
Innovation Solution
A catheter with a deflectable tip featuring a double helix design and a control wire, allowing for precise orientation and advancement of the guidewire across the occlusion, combined with a multilayer torque cable for enhanced torque transmission, facilitates successful crossing and subsequent dilation or stenting of the lesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a guidewire with sufficient rigidity is used to penetrate the occlusion, then the guidewire can enter the lesion effectively, but the guidewire may buckle or perforate the vessel due to excessive rigidity
Solution Approach 1:
The guidewire is divided into multiple segments with different mechanical properties: a stiff proximal section for torque transmission and a softer distal tip for safe lesion penetration. This segmentation allows the guidewire to have both the rigidity needed for control and the flexibility needed to avoid vessel perforation.
Solution Approach 2:
Different sections of the guidewire have different rigidity characteristics - the proximal portion is more rigid for operator control while the distal tip is softer for safe navigation through the occlusion. This local variation in quality resolves the contradiction between needing rigidity for penetration and flexibility to avoid damage.
2Object-affected harmful factors
If the distal end of the guidewire is made softer to prevent vessel perforation, then vessel safety is improved, but the guidewire cannot effectively enter or penetrate the occlusive lesion
Solution Approach 1:
The guidewire is divided into multiple segments with different mechanical properties: a stiff proximal section for torque transmission and a softer distal tip for safe lesion penetration. This segmentation allows the guidewire to have both the rigidity needed for control and the flexibility needed to avoid vessel perforation.
Solution Approach 2:
The operator first advances a softer exchange wire through the lesion before introducing the final guidewire. This preliminary action creates a pathway that reduces the penetration difficulty for subsequent devices, allowing the use of softer, safer guidewires while maintaining reliable lesion crossing.
3Ease of operation
If a pre-formed bend is added to the guidewire tip to assist orientation, then initial entry into the occlusion is improved, but the guidewire may take an unwanted path within the occlusion
Solution Approach 1:
The guidewire tip is made dynamically deflectable rather than having a fixed pre-formed bend. The tip can be actively oriented by the operator through external manipulation, allowing real-time adjustment of the wire path to navigate the occlusion accurately without deviating into unwanted trajectories.
Solution Approach 2:
A deflectable tip acts as an intermediary between the operator's control and the guidewire's path through the occlusion. This tip can be externally manipulated to orient the wire correctly, providing both the orientation assistance needed for entry and the path control needed to prevent unwanted trajectories.
4Device complexity
If conventional guidewires are used for CTO crossing, then the procedure can be performed with standard equipment, but the success rate is much lower and requires greater time and skill
Solution Approach 1:
The catheter system integrates multiple functions into a single device: guidewire delivery, distal positioning, orientation control, and support for subsequent angioplasty devices. This multi-functionality maintains procedural simplicity while significantly improving CTO crossing success rates through coordinated action of all components.
Solution Approach 2:
The deflectable tip catheter acts as an intermediary device that facilitates guidewire crossing of difficult CTOs by providing controlled orientation and support. It mediates between the operator's intent and the challenging occlusion, enabling successful crossing with standard equipment while improving success rates.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The catheter effectively navigates and crosses occlusions with improved rigidity and control, increasing the success rate of procedures and reducing the time and skill required for physicians to reestablish blood flow through total occlusions.
Implementation Method 1
a multilayer torque cable for enhanced torque transmission
Implementation Method 2
the deflectable tip may comprise a first helical coil having a first diameter and a second helical coil having a second diameter, the first diameter being larger than the second diameter. The first and second helical coils are arranged in the manner of a double helix.
Data Source
AI summary
A catheter comprises an elongate tubular member having a proximal end and a distal end, and a deflectable tip at the distal end of the elongate tubular member. The deflectable tip comprises a first helical coil having a first diameter and a second helical coil having a second diameter, the first diameter being larger than the second diameter. The first and second helical coils are arranged in the manner of a double helix. When viewed in cross-section, the first helical coil and the second helical coil are aligned at a first point on a circumference of each coil and misaligned at a second point on the circumference of each coil, where the second point is approximately 180 degrees from the first point. In certain embodiments the catheter further includes a dilatation balloon. Methods of use for crossing a chronic total occlusion are also described.