LAA Closure via Vacuum Inversion and Nested Stents
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Solution Overview
Problem
Current medical devices for closing the left atrial appendage are prone to incomplete closure, device dislodgement, and blood clot formation, which increases the risk of stroke in patients with atrial fibrillation.
Innovation Solution
A catheter system comprising a vacuum tube with a suction flange, a balloon, and a double stent assembly that includes an outer scaffold for expansion and anchoring within the left atrial appendage, an inner scaffold for engaging the distal portion of the appendage, and an occluder membrane to occlude the orifice, along with memory arms and tethers for retention, facilitating inversion and secure closure of the appendage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single stent or simple occluder device is used to close the left atrial appendage, then the device complexity is reduced, but the reliability of complete closure and prevention of device dislodgement deteriorates
Solution Approach 1:
The occlusion device is divided into multiple functional components: an outer stent for anchoring in the LAA orifice, an inner stent for engaging the inverted distal portion, an occluder membrane for sealing the orifice, and a vacuum tube system for inversion. This segmentation allows each component to perform its specific function optimally, ensuring reliable complete closure while managing complexity through modular design
Solution Approach 2:
The inner stent is positioned within the outer stent, creating a nested configuration. The vacuum tube is introduced through the catheter and positioned within the LAA. This nesting allows compact delivery through the catheter and enables the components to work together synergistically for secure anchoring and complete occlusion
2Reliability
If the distal portion of the left atrial appendage is inverted using a vacuum tube, then the engagement and closure of the appendage is improved, but the risk of blood clot formation on the device increases
Solution Approach 1:
The distal portion of the LAA is inverted into the inner stent before final occlusion is established. This preliminary inversion action creates a configuration where the LAA wall is pulled into the device, facilitating secure engagement and complete closure. The inversion is performed using the vacuum tube system before the occluder membrane is fully deployed
Solution Approach 2:
Instead of attempting to close the LAA in its normal anatomical configuration, the distal portion is inverted inside out into the inner stent. This inversion allows the vacuum tube to engage the LAA wall effectively, pulls the distal portion into the device for secure anchoring, and facilitates complete occlusion by creating a configuration where the LAA is drawn into the closure device
3Reliability
If a double stent assembly with multiple components is used, then the security of closure and prevention of dislodgement is improved, but the ease of operation and deployment deteriorates
Solution Approach 1:
The outer stent, inner stent, occluder membrane, and vacuum tube system are integrated into a single deliverable assembly that can be introduced through one catheter. The components are combined in a compact configuration that allows them to be deployed sequentially through coordinated manipulation of the catheter and its components, simplifying the overall deployment process despite the multiple functional elements
Solution Approach 2:
The device incorporates dynamic elements including the expandable stents that transition from a compressed delivery configuration to an expanded deployed configuration, and the vacuum tube system that dynamically engages and inverts the LAA. The occluder membrane is deployed dynamically after inversion is achieved. These dynamic transitions allow the complex multi-component device to be delivered through a relatively small catheter and then deployed in a controlled sequence
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 system effectively inverts and securely closes the left atrial appendage, preventing emboli release and promoting fibrosis, thereby reducing the risk of stroke by ensuring complete occlusion and long-term isolation of the appendage.
Implementation Method 1
When a vacuum is applied through the vacuum tube and the suction flange is attached to the distal portion of the left atrial appendage, the vacuum tube can be withdrawn in a direction away from the distal portion to invert the distal portion
Data Source
AI summary
Devices, systems, and methods for inverting and closing the left atrial appendage. In at least one embodiment of a method for closing a left atrial appendage of the present disclosure, the method comprises the steps of inverting a distal portion of a left atrial appendage, and constraining the inverted distal portion of the left atrial appendage using a device configured to fit within an interior of the left atrial appendage.