Composite ePTFE-Dacron Vascular Graft for Rapid Maturation
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Solution Overview
Problem
Current vascular access systems for hemodialysis, particularly those using expanded polytetrafluoroethylene (ePTFE) grafts, face challenges such as prolonged maturation time, high failure rates due to stenosis, and complications like bleeding and infection, which disrupt dialysis schedules and incur significant hospital costs.
Innovation Solution
A method involving a delivery device with a smooth, impermeable elongate tubular member that is deployed to displace stenosis radially, expanding the vessel lumen and improving patency, and a system for bypassing stenosis using a braided structure embedded in a catheter to enhance connection security and durability, allowing for temporary or permanent vascular access.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ePTFE graft material is used for AV graft, then ease of needle puncture and low complication rates are achieved, but prolonged maturation time and high failure rates due to stenosis occur
Solution Approach 1:
The graft system is divided into multiple segments: an ePTFE graft portion for reliable anastomosis and needle puncture, and a Dacron portion for rapid maturation and high flow. This segmentation allows each material to contribute its strengths, eliminating the need to wait for ePTFE maturation while maintaining low complication rates.
Solution Approach 2:
The invention uses a composite graft structure combining ePTFE and Dacron materials. The ePTFE section provides low complication rates and ease of needle puncture, while the Dacron section provides rapid maturation and high flow characteristics, resolving the contradiction between reliability and maturation time.
2Object-affected harmful factors
If ePTFE access grafts are used, then low complication rates are achieved, but high failure rates due to stenosis at the venous end occur
Solution Approach 1:
Different sections of the graft have different material properties optimized for their specific function. The ePTFE section at the arterial anastomosis provides low complication rates, while the Dacron section at the venous end provides high flow and resistance to stenosis, addressing the local quality issue at the venous anastomosis.
Solution Approach 2:
The composite ePTFE-Dacron graft allows the Dacron portion to be positioned at the venous anastomosis where high flow and stenosis resistance are needed, while the ePTFE portion handles the arterial side where low complication rates are critical.
3Ease of operation
If temporary catheter access is used during maturation, then hemodialysis access is provided, but additional risk of bleeding and infection occurs
Solution Approach 1:
The rapid-maturing Dacron graft is implanted in advance, allowing the patient to have functional vascular access available immediately without requiring temporary catheters. The graft matures quickly enough to provide permanent access, eliminating the need for temporary solutions and their associated risks.
Solution Approach 2:
The invention eliminates the need for temporary catheters (disposable short-term access devices) by providing a permanent graft that matures rapidly. This removes the intermediate step that exposes patients to bleeding and infection risks.
4Ease of operation
If direct anastomosis is performed, then vascular access is established, but 6 to 8 weeks maturation time is required before adequate blood flow
Solution Approach 1:
The Dacron portion of the composite graft is specifically chosen for its rapid maturation properties, allowing the anastomosis to become functional much faster than traditional ePTFE grafts. This maintains the simplicity of direct anastomosis while dramatically reducing the waiting time for adequate blood flow.
Data Source
AI summary
An apparatus and method are provided to treat a stenosis. A delivery device is provided that has an elongate tubular member coupled therewith. The elongate tubular member has an outside surface that is configured to prevent adherence of in vivo matter. The tubular member has a proximal end and a distal end and is reinforced along its length to maintain open lumen under a transverse load. The tubular member is placed in the vasculature such that the distal end of the elongate tubular member is disposed distal of a stenosis. The proximal end of the elongate tubular member is disposed inside the vessel, preferably at a location proximal of the stenosis. Thereafter, after a therapeutic period, the elongate tubular member is removed intact.