Stent Cleaning Assembly with Rotating Brush
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Solution Overview
Problem
Current methods for clearing occlusions from stents, such as balloon inflation and stent replacement, are inefficient and prone to rapid re-stenosis, as they do not completely remove occluding material or maintain the stent's original patency, leading to increased risks and time-consuming procedures.
Innovation Solution
A stent-cleaning assembly with a catheter component and a deployable cleaning member, such as a brush with a frictional surface, that can be actuated through an endoscope to engage and remove occluding material from the stent, using a threaded surface to stabilize the stent and a motorized mechanism for effective cleaning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If balloon inflation is used to compress or dislodge occluding material, then some patency is re-established, but complete removal of occluding material is not achieved leading to rapid re-stenosis
Solution Approach 1:
The brush assembly physically extracts and removes occluding material from the stent lumen through mechanical brushing action, rather than merely compressing it like a balloon. The bristles contact and dislodge deposits of biliary sludge and microbiological organisms from the stent interior surface, achieving complete removal to prevent re-stenosis
Solution Approach 2:
The brush assembly is designed to be rotatable and movable along the stent length, allowing dynamic cleaning action that adapts to the stent geometry and occlusion distribution. The rotational movement enables the bristles to effectively scrape occluding material from all surfaces of the stent lumen
2Reliability
If a second smaller stent is placed coaxially within the occluded stent, then a clean patent lumen is provided, but the lumenal cross-section is reduced leading to rapid re-stenosis
Solution Approach 1:
Instead of placing a smaller stent that reduces lumenal area, the brush assembly extracts occluding material while maintaining the original stent's full lumenal cross-section. This preserves the maximum possible flow area while achieving complete clearance of the stent interior surface
Solution Approach 2:
Rather than adding a second stent inside the first (which reduces area), the invention uses a brush assembly that cleans from the inside out, removing obstructions while preserving the original stent's full patency and cross-sectional area
3Reliability
If stent replacement is performed to provide a new clean open lumen, then complete removal of occlusion is achieved, but the procedure becomes time-consuming and increases risks
Solution Approach 1:
The brush assembly is self-contained and can be advanced through the stent independently, cleaning the stent interior without requiring removal or replacement of the stent itself. This allows the stent to remain in place while being thoroughly cleaned by the rotating brush mechanism
Solution Approach 2:
The brush assembly performs preliminary cleaning action on the stent interior before final stent deployment or activation, ensuring the lumen is completely clear of occluding material while the stent remains in its delivery configuration
4Reliability
If a brush or cutting mechanism is used to remove stenotic material, then complete clearance is achieved, but damage to the stent surface and surrounding tissue may occur
Solution Approach 1:
The brush assembly uses soft bristles made of materials like Teflon or silicone rubber that are specifically selected to be gentle on the stent surface. The bristle hardness and flexibility are locally optimized to effectively remove occluding material while being compliant enough to avoid damaging the metallic stent structure or surrounding tissue
Solution Approach 2:
The brush design converts the potentially harmful mechanical action of scraping into a beneficial cleaning process by using compliant bristles that flex to conform to the stent geometry, distributing force evenly to remove deposits without concentrating stress that could damage the stent or tissue
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 assembly effectively removes occluding material, maintaining the stent's patency and reducing the likelihood of re-stenosis, while minimizing damage to the stent's surface and surrounding tissue, thus providing a more efficient and safer treatment option.
Implementation Method 1
a threaded surface to stabilize the stent
Implementation Method 2
a deployable cleaning member, including a frictional cleaning surface such as a brush
Data Source
Figure 1A
Figure 1B
Figure 2~3
AI summary
An assembly and method for removing occlusive material from a stent. The assembly includes an elongate catheter with an elongate flexible shaft disposed therethrough and a cleaning end disposed distally upon the shaft. The cleaning end is configured to engage and dislodge the occlusive material.