Endoluminal Stent Cutting Mechanism for Custom Lengths
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Solution Overview
Problem
Current stent deployment systems for biliary and pancreatic ducts are inefficient, as they require multiple stents and precise length assessment, which can be tedious and inaccurate due to the two-dimensional nature of fluoroscopic projections in three-dimensional ducts, making it difficult to open larger diameter ducts effectively.
Innovation Solution
A system and method utilizing an elongate stent body with an outer sheath and an endoluminal cutting mechanism connected to a drive cable, allowing for the customization and deployment of stents of desired lengths within the duct, enabling the placement of multiple stents and accommodating larger diameters with fewer stents by severing the stent body to form stents of appropriate lengths endoluminally.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple stents are placed to open larger diameter ducts, then the duct opening effectiveness is improved, but the procedural time and complexity increase
Solution Approach 1:
Multiple individual stents are merged into a single modular stent system composed of multiple expandable segments that can be deployed together as one unit. The stent body includes multiple radially expandable segments connected in series along the longitudinal axis, allowing the system to function as both multiple separate stents and as a single integrated structure, thereby reducing procedural time while maintaining duct opening effectiveness
Solution Approach 2:
The stent is segmented into multiple independent expandable sections that can be selectively deployed. Each segment can expand independently to provide the necessary duct opening effect, and the segmented design allows for controlled deployment along the duct length, reducing the need for multiple separate stent placements
2Reliability
If multiple stents are placed to open larger diameter ducts, then the duct opening effectiveness is improved, but the device complexity increases
Solution Approach 1:
Multiple stent functions are merged into a single modular device where multiple expandable segments are integrated into one stent body. This unified structure with multiple segments provides the effectiveness of multiple stents while reducing system complexity by eliminating the need for separate stent delivery systems
Solution Approach 2:
The modular stent system performs multiple functions within a single device: it can expand to different diameters, accommodate different duct lengths, and provide sufficient radial force through multiple segments. This multi-functionality replaces the need for multiple different stent sizes and types, simplifying the overall system
3Ease of operation
If stent length is assessed using fluoroscopic projection, then the assessment process is simple, but the measurement precision deteriorates
Solution Approach 1:
Radiopaque markers with distinct radiographic appearances are incorporated at the proximal and distal ends of the stent body. These markers provide clear, easily distinguishable reference points on fluoroscopic images, enabling accurate length assessment while maintaining the simplicity of fluoroscopic evaluation. The markers may include different radiopaque materials or patterns that enhance visibility and measurement precision
Solution Approach 2:
Radiopaque markers serve as intermediary reference elements between the stent structure and the fluoroscopic imaging system. These markers provide measurable reference points that bridge the gap between the three-dimensional stent and the two-dimensional projection, enabling more accurate length assessment through fluoroscopy without requiring complex imaging techniques
Data Source
AI summary
Described herein are a system and a method for forming a stent of a desired length endoluminally. The system includes an elongate stent body and an outer sheath overlying the stent body. An endoluminal cutting mechanism is operatively connected to a drive cable in communication with the outer sheath. The cutting mechanism is configured to cut the stent body in response to motion of the drive cable. The method of forming the stent of a desired length endoluminally includes directing a system including an elongate stent body and an outer sheath overlying the stent body into a body lumen, positioning the stent body at an endoluminal site, and severing the stent body to form a stent of a desired length at the endoluminal site. An undeployed portion of the stent body remains in the outer sheath for optional deployment in a subsequent severing operation.