Ablation Catheter Needles for Paravalvular Leak Closure
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Solution Overview
Problem
Percutaneous and surgical heart valve replacements often result in paravalvular leaks due to mismatched shapes between the stent frame and the implantation site, necessitating a minimally invasive method to effectively repair these leaks without the risks associated with open-heart surgery.
Innovation Solution
A transcatheter system using an ablation catheter with moveable needle electrodes that apply radio frequency energy to weld or shrink tissue, reducing the size of the leak opening by moving needles to penetrate the stent and surrounding tissue, thereby closing or minimizing the leak.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a percutaneous valve delivery approach is used, then the invasiveness of the procedure is reduced, but paravalvular leakage occurs due to shape mismatch between the stent frame and implantation site
Solution Approach 1:
The delivery system is divided into multiple independent components: an inner tube for guidewire insertion, an outer tube or sheath that is moveable relative to the inner tube, and needle electrodes that can be independently positioned. This segmentation allows the needles to be precisely deployed through the outer tube to reach the leak site while keeping the outer tube in position, enabling targeted treatment without compromising the overall device placement
Solution Approach 2:
The patent replaces traditional mechanical suturing or clipping methods with radio frequency energy application. The needle electrodes deliver RF energy to weld or shrink the tissue and stent frame, creating a thermal effect that seals the paravalvular leak. This substitution of thermal energy for mechanical closure provides a minimally invasive approach that avoids the need for complex mechanical fastening mechanisms
2Reliability
If open-heart surgery is performed to repair paravalvular leaks, then the sealing effectiveness is improved, but the patient is exposed to high risks including infection, stroke, and renal failure
Solution Approach 1:
The patent introduces an intermediary delivery system that bridges the gap between percutaneous access and effective leak sealing. The catheter system with movable outer tube and needle electrodes serves as an intermediary mechanism that delivers RF energy to the leak site through a minimally invasive pathway, achieving surgical-level sealing effectiveness without requiring open-heart surgery or general anesthesia
Solution Approach 2:
The patent changes the physical state and properties of the tissue and stent frame through radio frequency energy application. The RF energy causes thermal coagulation and shrinkage of the tissue, changing its physical properties to achieve closure of the paravalvular leak. This parameter change (thermal effect) provides an alternative to mechanical surgical repair
3Reliability
If the stent frame shape is made to match the implantation site, then the paravalvular leakage is reduced, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent applies preliminary action by positioning the needle electrodes through the movable outer tube before delivering the therapeutic RF energy. The outer tube is first positioned at the leak site, then the needles are advanced through it to the target location. This preliminary positioning ensures accurate delivery of the sealing energy without requiring complex pre-shaping of the stent frame
Solution Approach 2:
The patent employs self-service by using the patient's own tissue response to RF energy application. The thermal energy causes the tissue and stent frame to shrink and weld together automatically, utilizing the body's natural healing and coagulation responses to achieve sealing. This self-service mechanism eliminates the need for complex mechanical adjustment or customization of the stent frame geometry
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 method effectively seals paravalvular leaks by using RF energy to weld or shrink tissue, providing a minimally invasive solution for both percutaneously and surgically implanted valves, reducing the risk of complications associated with open-heart surgery.
Implementation Method 1
Radio frequency energy can then be applied to the one or more needle electrodes to weld tissue together and/or shrink tissue
Implementation Method 2
Radio frequency energy can then be applied to the one or more needle electrodes to weld tissue together and/or shrink tissue
Data Source
AI summary
An ablation catheter including an inner tube having a length, a distal end and a longitudinal axis, a plurality of needles extending from the distal end of the inner tube and biased away from the longitudinal axis, an outer sheath slideably moveable relative to the inner tube to surround at least a portion of the length of the inner tube and its extending needles, and a radio frequency energy source electrically connected to the plurality of needles.