Tissue-Ingrowth Cuff Structure for Stable Catheter Anchoring
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Solution Overview
Problem
Existing catheters with small cuffs face issues with mechanical stability and bacterial ingress, leading to potential catheter expulsion and infection, while existing tissue-ingrowth cuffs rely solely on tissue anchoring for stability.
Innovation Solution
A cuff design featuring two wide Dacron bands with a polysulfone ring and angled hooks for enhanced mechanical grip, combined with a polysulfone anchor ring, to stabilize the catheter and hinder bacterial progression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If small cuffs are used on catheters, then the device complexity is reduced, but the mechanical stability and bacterial barrier function deteriorate
Solution Approach 1:
The cuff is divided into two separate Dacron bands instead of a single continuous band. Each band can independently engage with the anchor ring, providing redundant mechanical attachment points. This segmentation increases mechanical stability while maintaining relatively simple overall structure.
Solution Approach 2:
The cuff combines two different materials: Dacron bands for tissue ingrowth and mechanical flexibility, and a polysulfone anchor ring for rigid structural support and hook engagement. This composite construction provides both mechanical stability and biological integration.
2Device complexity
If small cuffs are used on catheters, then the device complexity is reduced, but the bacterial barrier function deteriorates
Solution Approach 1:
The cuff extends significantly in the longitudinal dimension along the catheter, creating a longer barrier path for bacteria. The two wide bands spaced apart create a multi-dimensional barrier that bacteria must traverse, increasing the effective barrier length without substantially increasing structural complexity.
3Reliability
If wide Dacron bands are used, then the mechanical grip and bacterial barrier are improved, but the device complexity increases
Solution Approach 1:
The wide Dacron bands serve multiple functions simultaneously: they provide mechanical grip on the catheter, create a barrier to bacterial ingress, and facilitate tissue ingrowth for long-term anchoring. This multi-functionality reduces the need for additional separate components.
Solution Approach 2:
The mechanical anchoring function (via wide bands), biological anchoring function (via tissue ingrowth), and bacterial barrier function are merged into a single integrated cuff structure, avoiding the need for separate anchoring mechanisms.
4Device complexity
If only tissue anchoring is used for cuff stability, then the device complexity is reduced, but the reliability against displacement deteriorates
Solution Approach 1:
The angled hooks on the anchor ring are pre-configured to engage with the Dacron bands before tissue ingrowth occurs. This preliminary mechanical engagement provides immediate stabilization, while the tissue ingrowth process subsequently reinforces this initial anchoring.
Solution Approach 2:
The anchoring system transitions from an initial static mechanical engagement (hooks on bands) to a dynamic biological process (tissue ingrowth) that progressively strengthens the anchoring over time, creating a dual-phase stabilization mechanism.
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 design provides improved mechanical stability and reduced bacterial ingress, preventing catheter displacement and infection, by enhancing the mechanical grip and creating a barrier against bacterial migration.
Implementation Method 1
The two small protrusions, at the moment of implantation, thanks to a simple and light pressure exercised from the outside on them, are anchored to the underlying muscle band
Implementation Method 2
From a biological point of view, it is clear that this considerable width also generates an increased barrier to the progression of bacteria
Implementation Method 3
Tissue-ingrowth material is affixed to the outwardly facing surface of the cuff within a subcutaneous tunnel after catheter implantation, thus anchoring the catheter against movement
Data Source
AI summary
An external end device has a casing, including a base, in which a distal opening is formed which receives a funnel-shaped septum having a tube trunk. Inside the tube trunk, the catheter is connected to the distal section of the fitting. A tubular coating has a proximal end adapted to be grafted onto the tube trunk and a distal end coaxially adhering to the catheter. A pair of bands of tissue-ingrowth material is fixed on the tubular coating, and an anchor ring, equipped with anchoring means, is sandwiched between the bands.