Shape-Memory Stylet Cryoablation Catheter for Continuous Lesions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ablation technologies face challenges in creating continuous and complete lesions in heart tissue due to varying anatomical contours and patient-specific anatomy, leading to incomplete pulmonary vein isolation and high rates of reconnection, which are not effectively addressed by current flexible cryoprobes and RF ablation catheters.
Innovation Solution
The use of a cryoablation catheter with a shape-memory stylet that is pre-set to match the desired lesion shape, allowing for adjustable and flexible catheter positioning to ensure complete tissue contact and efficient thermal conductivity, thereby forming continuous lesions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If flexible cryoprobes or RF ablation catheters are used, then the catheter can adapt to varying anatomical contours, but the lesions formed are incomplete and discontinuous due to inability to maintain consistent tissue contact
Solution Approach 1:
The stylet is pre-formed with a specific curved shape that corresponds to the desired lesion geometry. This preliminary shaping of the stylet ensures that when the catheter is deployed, the ablation element is pre-positioned to match the anatomical contour, guaranteeing continuous and complete lesion formation without requiring complex real-time adjustments during the procedure.
Solution Approach 2:
The stylet acts as an intermediary element between the operator and the catheter shape. By manipulating the stylet, the operator can precisely control the catheter's configuration to match varying anatomical contours. The stylet serves as a mechanical mediator that translates operator intent into accurate catheter positioning, ensuring both adaptability and lesion completeness.
2Adaptability or versatility
If the catheter is made more flexible to accommodate anatomical variations, then the catheter can reach target areas, but the structural support needed for stable tissue contact is compromised
Solution Approach 1:
The catheter is divided into distinct functional segments: a flexible delivery shaft for navigation, a rigid or semi-rigid stylet for shape control, and an ablation section for lesion formation. This segmentation allows each component to optimize its properties - the delivery shaft provides flexibility for anatomical adaptation, while the stylet provides structural support for stable tissue contact during ablation.
Solution Approach 2:
The catheter employs a flexible outer sheath or shaft that can bend and conform to anatomical structures, while the internal stylet provides the necessary structural support. This combination of flexible external structure with rigid internal support allows the catheter to both adapt to anatomical variations and maintain stable tissue contact for complete lesion formation.
3Strength
If a rigid stylet is used to maintain catheter shape, then structural support is improved, but the catheter cannot adapt to varying anatomical contours
Solution Approach 1:
The stylet is designed with varying properties along its length - the distal portion that contacts tissue may be more rigid to ensure stable contact, while proximal portions may be more flexible to allow catheter manipulation and adaptation. This local variation in rigidity allows the catheter to simultaneously maintain structural support where needed and adapt to anatomical contours in other regions.
4Reliability
If multiple ablation points are used to ensure complete isolation, then the isolation effectiveness is improved, but the procedure time increases significantly
Solution Approach 1:
The pre-formed stylet enables the catheter to maintain continuous contact with the tissue along the entire intended lesion path. This continuity allows the ablation energy to be applied continuously along the pulmonary vein circumference in a single deployment, rather than requiring multiple discrete ablation points applied sequentially. The useful action of tissue ablation continues uninterrupted, significantly reducing procedure time while maintaining complete isolation effectiveness.
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 solution enables durable and safe electrical signal isolation within the heart chambers, including pulmonary vein isolation, by ensuring consistent contact and effective lesion formation despite anatomical variations, reducing the risk of reconnection.
Implementation Method 1
the stylet comprises a shape-memory material. In some embodiments, at least a distal portion of the stylet is pre-set with a shape that corresponds to a desired shape of the lesion to be formed
Implementation Method 2
The use of a cryoablation catheter with a shape-memory stylet that is pre-set to match the desired lesion shape, allowing for adjustable and flexible catheter positioning to ensure complete tissue contact and efficient thermal conductivity, thereby forming continuous lesions
Data Source
AI summary
An ablation apparatus for creating a lesion in target tissue, the ablation apparatus having an ablation shaft including a handle, a first portion, an ablation portion, distal tip, at least one ablation energy delivery lumen, at least one ablation energy return lumen, and a stylet lumen that extends substantially along a length of the ablation shaft from the handle to at least the ablation portion. The ablation apparatus also includes a stylet that is capable of being inserted into the stylet lumen where the stylet is made of a shape-memory material.