Reentry Catheter Articulating Cannula Subintimal Re-entry
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Solution Overview
Problem
Current methods for crossing chronic occlusions in arteries, particularly calcified lesions, face challenges in maneuvering guide wires through subintimal spaces and re-entering the true lumen, often requiring high forces and resulting in sub-optimal re-entry locations due to the tendency of catheters to back out.
Innovation Solution
A medical device featuring an articulating cannula or sharp reentry member with a segmented design and eccentric force application mechanism, allowing precise re-entry into the true vessel lumen from the subintimal space with reduced force requirements and improved stability and control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional catheters are used for re-entry into the true lumen, then the procedure can be performed, but high forces are required and catheter backout occurs resulting in sub-optimal re-entry locations
Solution Approach 1:
The reentry catheter is divided into multiple segments including a proximal shaft, a distal shaft, and an articulating cannula. The articulating cannula can be selectively positioned relative to the shafts, allowing the operator to control the reentry point precisely. This segmentation enables the catheter to maintain stability while applying focused force at the reentry site, preventing backout and achieving optimal re-entry location.
Solution Approach 2:
The articulating cannula is designed to be movable relative to the shafts, transitioning between a first position for stable catheter delivery and a second position for controlled reentry. This dynamic configuration allows the catheter to adapt during the procedure: stable during delivery, then capable of precise articulation at the reentry point to reduce force requirements and prevent backout.
2Ease of operation
If conventional catheters are used for re-entry into the true lumen, then the procedure can be performed, but catheter backout occurs resulting in loss of position control
Solution Approach 1:
The segmented design with proximal and distal shafts connected by an articulating cannula provides independent control zones. The proximal shaft remains stable during delivery, while the distal shaft and articulating cannula can be precisely positioned for reentry. This segmentation prevents unwanted movement and backout, improving both ease of operation and reliability.
Solution Approach 2:
The articulating cannula acts as an intermediary between the stable proximal shaft and the reentry point at the distal end. It transmits controlled movements from the operator while filtering out unwanted motions that could cause backout, thereby improving position control and reentry success.
3Strength
If high forces are applied for re-entry, then penetration of subintimal space can be achieved, but catheter stability decreases and backout occurs
Solution Approach 1:
The articulating cannula provides dynamic positioning that allows the operator to apply penetration force precisely where needed while maintaining overall catheter stability. The cannula can articulate to accommodate the penetration action without transmitting destabilizing forces to the proximal shaft, thus achieving both strength for penetration and stability to prevent backout.
Solution Approach 2:
The catheter design provides different properties at different locations: the proximal shaft maintains stability and control, while the distal shaft and articulating cannula are designed to provide localized penetration capability. This local differentiation allows high force application at the reentry point without compromising overall catheter stability.
Data Source
AI summary
The invention generally relates to method and apparatus for crossing an obstruction in a tubular member, and more particularly to a medical device method for crossing of a chronic occlusion in a subintimal or interstitial space of an artery.