Catheter Injection System for Circumferential Ablation
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Solution Overview
Problem
Current RF catheter systems for treating cardiac arrhythmias and hypertension are inefficient, cause tissue injury, and pose safety risks due to incomplete ablation, long procedure times, and radiation exposure, with a lack of effective technologies for circular ablation of ostial walls in blood vessels.
Innovation Solution
A disposable catheter system with multiple expandable injector tubes and a centering mechanism for circumferential ablation of muscle and nerve fibers, using ablative fluids like ethanol to create a ring of damage around the ostium of blood vessels, reducing the need for capital equipment and minimizing tissue perforation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If RF catheter systems are used to ablate tissue, then conducting tissue can be ablated for treating cardiac arrhythmias and hypertension, but thermal or cryoablative injury occurs to surrounding tissue and significant capital equipment is required
Solution Approach 1:
The patent replaces thermal RF energy delivery with mechanical ethanol injection. The catheter delivers liquid ethanol directly to the target tissue through injection needles, using mechanical fluid delivery instead of thermal energy fields. This substitution eliminates thermal injury to surrounding tissue while achieving effective ablation through direct chemical exposure of the tissue to ethanol.
Solution Approach 2:
The patent uses hydraulic principles to deliver ethanol through a fluid injection system. The catheter includes injection needles connected to fluid delivery mechanisms that propel ethanol directly into the target tissue. This hydraulic approach enables precise, controlled delivery of the ablative agent without the need for thermal energy generation systems.
2Measurement precision
If RF catheters ablate one focus at a time, then targeted ablation is achieved, but the procedure becomes technically challenging and very time consuming
Solution Approach 1:
The catheter incorporates multiple injection needles arranged in a circumferential array around the ostium. This segmentation allows simultaneous ablation of multiple tissue foci around the entire ostium circumference, rather than treating one spot at a time. The multiple needles work in parallel to create complete circumferential ablation in a single deployment, dramatically reducing procedure time while maintaining precise targeting.
Solution Approach 2:
The patent merges multiple ablation functions into a single catheter deployment. By combining multiple injection needles into one integrated catheter structure, the system performs circumferential ablation of the entire ostium in one action, rather than requiring sequential treatment of multiple separate sites. This consolidation of functions reduces the number of procedural steps and overall treatment time.
3Reliability
If RF energy is applied inside the renal artery to ablate sympathetic nerve fibers, then hypertension treatment is achieved, but long-term sequelae such as restenosis, embolization of debris, or uneven ablation may occur
Solution Approach 1:
The patent replaces thermal RF ablation with mechanical ethanol injection for sympathetic nerve denervation. By injecting liquid ethanol directly into the renal artery wall, the system achieves nerve fiber ablation through chemical exposure rather than thermal energy. This mechanical delivery method avoids the thermal damage, debris generation, and restenosis risks associated with RF heating, while providing more uniform ablation through direct ethanol contact with the tissue.
4Reliability
If current RF ablation technologies are used, then tissue ablation is achieved, but very long fluoroscopy and procedure times lead to high levels of radiation exposure to both patient and operator
Solution Approach 1:
The patent replaces RF energy delivery requiring fluoroscopic guidance with a mechanical ethanol injection system that can be deployed and operated with minimal imaging. The injection catheter system uses straightforward mechanical advancement and fluid delivery that does not require continuous fluoroscopy for operation, thereby dramatically reducing radiation exposure to both patients and operators while maintaining effective tissue ablation.
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
Enables efficient, reproducible, and safe circumferential ablation of cardiac arrhythmias and hypertension treatment, reducing procedure time and radiation exposure, while ensuring complete tissue damage around the ostium of blood vessels.
Implementation Method 1
injection of an ablative fluid into the ostial wall... capable of producing damage in the tissue that surrounds the ostium
Data Source
AI summary
At the present time, physicians often treat patients with atrial fibrillation (AF) using radiofrequency (RF) catheter systems to ablate conducting tissue in the wall of the Left Atrium of the heart around the ostium of the pulmonary veins. These systems are expensive and take time consuming to use. The present invention circular ablation system CAS includes a multiplicity of expandable needles that can be expanded around a central axis and positioned to inject a fluid like ethanol to ablate conductive tissue in a ring around the ostium of a pulmonary vein quickly and without the need for expensive capital equipment. The expansion of the needles is accomplished by self-expanding or balloon expandable structures. The invention includes centering means so that the needles will be situated in a pattern surrounding the outside of the ostium of a vein. Also included are members that limit the distance of penetration of the needles into the wall of the left atrium. The present invention also has application to ablating tissue around the ostium of a renal artery for the treatment of hypertension.