Percutaneous Implant Retrieval Device with Dynamic Snare
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Solution Overview
Problem
Current methods for retrieving implanted medical devices through percutaneous techniques often fail to consistently and securely engage the device, posing risks such as blood vessel or organ perforation due to repeated attempts.
Innovation Solution
A retrieval system comprising an outer elongate body with a retrieval tether and an inner elongate body, where the retrieval tether is used as a guide to advance the retrieval device to the implant, and a retrieval cable is used to capture and remove the implant, with features like pre-shaped curves, durometer variations, and a snare mechanism for secure engagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If percutaneous retrieval techniques are used to remove implants, then patient trauma is reduced compared to surgical retrieval, but the retrieval device may not consistently and securely engage the implanted device
Solution Approach 1:
The retrieval device incorporates a dynamic snare mechanism that can transition from a compressed delivery configuration to an expanded engagement configuration. The snare cables are arranged to form a loop that dynamically expands to capture the implant, providing adaptive engagement that maintains reliability while preserving the percutaneous approach's low-trauma benefit.
Solution Approach 2:
The device changes its geometric parameters during operation - the snare loop expands from a small delivery profile to a large engagement profile. This parameter change allows the device to maintain a small catheter profile for percutaneous insertion while achieving a large engagement area for secure implant capture, resolving the contradiction between minimal invasion and reliable engagement.
2Productivity
If repeated attempts are made to engage the implanted device, then retrieval may eventually succeed, but the risk of perforation of blood vessels or organs increases
Solution Approach 1:
The snare mechanism is pre-configured within the delivery catheter with cables and loops positioned to automatically engage the implant upon deployment. This preliminary arrangement eliminates the need for repeated manual engagement attempts, allowing the device to capture the implant in a single action and thereby preventing perforation risks associated with multiple attempts.
Solution Approach 2:
The snare mechanism is designed to self-engage the implant through its own structural configuration. The loop geometry and cable arrangement automatically constrict around the implant when deployed, enabling the device to secure itself to the target without requiring repeated external manipulation attempts, thus reducing perforation risk while ensuring retrieval success.
3Device complexity
If a simple catheter design is used for retrieval, then device complexity is reduced, but the ability to securely capture and remove the implant is compromised
Solution Approach 1:
The retrieval device uses a nested structure where the snare cables and loop are contained within the delivery catheter in a compressed state. This nesting allows the complex snare mechanism to be delivered through a simple percutaneous catheter, maintaining low device complexity for insertion while providing the capability for secure implant capture through the deployed snare configuration.
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 enables secure and efficient percutaneous retrieval of medical implants with reduced risk of trauma, allowing for the removal of implants without causing significant harm to the patient.
Implementation Method 1
The retrieval cable may be constructed from a shape memory alloy
Data Source
Figure 1~3
Figure 4A
Figure 4B
AI summary
Devices and methods are disclosed for retrieving an implant or tissue anchor during the course of a percutaneous medical procedure. An implant is provided having a retrieval tether attached to it. The retrieval tether is attached to the implant on one end, and the proximal end of the tether can be threaded through an implant retrieval device. The retrieval device comprises an inner elongate body that is used to capture and secure the retrieval tether. The retrieval device also comprises an outer elongate body that may be configured to be advanced over the retrieval tether from a location remote from the implant (e.g., outside a patient's body) to contact and retrieve the implant after it has been deployed and/or implanted within a patient' s body.