Radially Expandable Mesh Prosthesis for Caval-Aortic Access

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Solution Overview

Problem

Current transcatheter procedures for cardiovascular abnormalities face challenges such as inadequate hemostasis and limited guidewire access due to the inadequacy of existing occluder devices for caval-aortic access, particularly in patients with femoral artery caliber issues or intravascular disease, leading to vascular complications.

Innovation Solution

A radially expandable mesh prosthesis with a tension coil spring and fabric discs that self-expand to form discs for enhanced hemostasis and guidewire access, featuring a telescopic design and 'billowing' nitinol weave to occlude vascular rents, along with a system for delivering and redeploying the prosthesis using a tubular sheath and inner elongate member.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If nitinol occluder devices are used to close caval-aortic access ports, then the access port can be closed, but hemostasis is inadequate and guidewire access is blocked

Engineering Contradiction:
Improvehemostasis effectivenessVSAvoidguidewire access
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The occluder device is divided into multiple discrete discs (first disc in the aorta, second disc in the IVC, and optional intermediate discs) rather than a single continuous structure. This segmentation allows each disc to independently seal against the vessel wall while maintaining a central channel for guidewire passage through the device, thus achieving both hemostasis and guidewire access.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a two-dimensional planar occluder to a three-dimensional structure with discs extending radially outward from the central axis. The discs create radial sealing surfaces against the vessel wall while the central lumen maintains axial guidewire access, adding a radial dimension to the sealing mechanism.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If large introducer sheaths are placed in the femoral artery for TAVR, then transcatheter aortic valve replacement can be performed, but vascular complications occur

Engineering Contradiction:
Improveaccess route optionsVSAvoidvascular complications
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The occluder device acts as an intermediary sealing element placed at the caval-aortic junction to close the access port after device delivery. This eliminates the need for large introducer sheaths in the femoral artery, as the access can be achieved through the IVC instead, and the occluder seals the puncture site to prevent vascular complications.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If existing occluder devices are used for caval-aortic access, then the procedure can be completed, but the devices are imperfectly suited for this application

Engineering Contradiction:
Improveprocedure completionVSAvoiddevice suitability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

Different portions of the occluder device have different properties optimized for their specific functions: the first disc has a radiopaque marker ring for imaging guidance, the intermediate discs have specific radial heights for sealing, and the second disc has properties optimized for IVC sealing. Each local region is tailored to its specific requirement.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The occluder device incorporates multiple materials with different properties: nitinol for the frame structure providing superelasticity and shape memory, fabric or graft material for the disc surfaces providing sealing and thrombogenicity, and radiopaque materials for imaging. This composite construction optimizes overall device performance.

Inventive Principle:
Principle #40Composite materials

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 provides improved hemostasis and uninterrupted guidewire access, reducing the risk of vascular complications and facilitating safer transcatheter procedures by preventing axial displacement of the prosthesis and ensuring effective sealing of leaks in both arteries and veins.

Implementation Method 1

the resilient member is a tension coil spring configured to contract into a relaxed state when not being stretched that results in the prosthesis being shortened along the axis and expanded radially when the resilient member is relaxed

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a radially expandable mesh body that is configured to self-expand into at least one disc after becoming radially unconstrained

Methodology Applied
Scientific EffectShape Memory Alloy: Shape Memory Alloy

Implementation Method 3

The prosthesis can include a material disposed within the mesh that is configured to encourage coagulation when exposed to blood

Methodology Applied
Scientific EffectCoagulation: Coagulation

Data Source

PatentEP3122284B1Devices for closure of transvascular or transcameral access ports
Publication Date: 2021.01.13 RAFIEE NASSER
  • EP3122284B1 patent drawingFigure 1A~1B
  • EP3122284B1 patent drawingFigure 1C~1D
  • EP3122284B1 patent drawingFigure 2A~2D

AI summary

The present disclosure provides a variety of prostheses, delivery systems and techniques to facilitate closure of transvascular or transcameral access ports. Various embodiments of prostheses are provided including a plurality of radially expandable mesh discs filled with material to facilitate coagulation and to reduce or stop leakage from punctures in vessel walls.