Vena Cava Filter with Deployable Anchors
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Solution Overview
Problem
Existing Vena Cava filters face challenges in secure anchoring and reliable retrievability due to the mobility of the Vena Cava and limitations in anchor wire thickness and location, leading to complications during retrieval.
Innovation Solution
A filter design with expandable anchoring legs that can be reconfigured between a pre-deployed, non-anchoring configuration and a deployed, anchoring configuration, using obturators to move the anchoring legs and form anchors along their length for secure engagement with the vessel wall, allowing for secure anchoring and easy retrieval.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If aggressive tissue anchors are used to secure the blood filter, then anchoring strength is improved, but retrieval reliability deteriorates
Solution Approach 1:
The anchor wires are designed to be dynamically configurable between a deployed anchoring configuration and a retracted non-anchoring configuration. During implantation, the anchor wires extend outward to engage the vessel wall for secure anchoring. During retrieval, the anchor wires are retracted into the hollow legs, transforming the filter into a more compliant structure that can be safely removed without tissue damage.
Solution Approach 2:
The physical state of the anchor wires is changed between two distinct configurations: an extended state for anchoring and a retracted state for retrieval. This parameter change allows the same structural element to serve opposing functions - providing strong mechanical engagement when needed and minimizing tissue interaction when retrieval is required.
2Strength
If the anchor wires are made thicker for better anchoring, then anchoring strength is improved, but the device complexity and delivery difficulty increase
Solution Approach 1:
The anchor wires are nested within hollow legs during the delivery phase. This nesting allows the anchor wires to be contained within a compact delivery profile, reducing the overall device size and simplifying catheter delivery. Upon deployment, the anchor wires are advanced outward from the hollow legs to their anchoring positions, providing strong engagement without requiring the entire device to be large or complex.
Solution Approach 2:
The anchoring function is segmented from the main filter body through the use of separate hollow legs containing deployable anchor wires. This segmentation allows the anchor wires to be independently controlled and deployed only when needed, reducing the complexity of the overall device while maintaining effective anchoring capability.
3Ease of operation
If the blood filter is made more compliant for easy delivery, then ease of operation is improved, but anchoring stability deteriorates
Solution Approach 1:
The filter structure dynamically transitions between two states: a compliant, collapsed state during delivery that allows easy navigation through the vasculature, and a rigid, expanded state during anchoring that provides stable engagement with the vessel wall. The deployment of hollow legs and anchor wires transforms the compliant filter into a structurally stable anchored device.
Solution Approach 2:
The filter is delivered in a preliminary collapsed configuration that minimizes its profile and maximizes compliance for easy delivery. Once positioned at the target site, the filter is deployed into its functional configuration with extended hollow legs and anchor wires, achieving the necessary structural stability for anchoring without compromising the ease of initial delivery.
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 filter achieves secure anchoring within the Vena Cava while enabling reliable retrieval by reconfiguring its anchoring legs, reducing the risk of migration and misalignment, and improving the stability and maneuverability of the device.
Implementation Method 1
Each of the one or more first anchoring legs in the deployed, anchoring configuration may have a first anchor sized and configured to anchor the filter within the body lumen
Data Source
AI summary
An implantable and removable filter that may be implanted in and/or removed from a body lumen, such as the Vena Cava. The filter including tissue anchors on expandable anchoring legs, which can be selectively moved between a non-anchoring or pre-deployed configuration into an anchoring or deployed configuration by obturators that are movable inside the anchoring legs.