Expandable Re-entry Catheter for Subintimal True-Lumen Access
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Solution Overview
Problem
Chronic total occlusions in blood vessels pose challenges for recanalization, as existing methods struggle to effectively re-enter the true lumen from the subintimal space, making it difficult to restore blood flow.
Innovation Solution
A subintimal recanalization catheter assembly with an expandable structure and penetration member, where the expandable structure is actuated between a collapsed and expanded configuration to facilitate re-entry into the true lumen by deflecting the inner tubular member towards the vessel lumen, allowing the penetration member to pierce through the tissue layers and re-establish blood flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a subintimal pathway is created around the occlusion, then the catheter can bypass the blockage, but re-entering the true lumen becomes difficult
Solution Approach 1:
The catheter employs a dynamic tip section that can change its configuration between straight and curved states. When in the subintimal space, the tip is straight for easy navigation. When re-entering the true lumen, the tip curves to follow the vessel wall and penetrate back into the lumen, making the re-entry process easier and more effective.
Solution Approach 2:
The catheter is divided into distinct functional segments: a proximal control section, a mid-section, and a distal tip section with variable curvature. This segmentation allows independent control of each section, enabling the operator to navigate the subintimal pathway with one configuration and then re-enter the true lumen by changing the tip configuration without affecting the rest of the catheter.
2Productivity
If the catheter is advanced into the subintimal space, then recanalization can be attempted, but precise re-entry into the true lumen is difficult to achieve
Solution Approach 1:
The catheter incorporates radiopaque markers at the tip and along the shaft that provide visual feedback under fluoroscopic guidance. This allows the operator to precisely track the catheter's position in the subintimal space and accurately determine when and where the tip is about to re-enter the true lumen, achieving precise control over the re-entry location.
Solution Approach 2:
The catheter tip is designed with a curved configuration that naturally follows the curvature of the vessel wall when in the subintimal space. This curved shape acts as a guide, directing the tip toward the true lumen and improving the precision of re-entry by leveraging the natural geometry of the vessel structure rather than attempting straight-line penetration.
Data Source
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AI summary
A subintimal recanalization catheter assembly for recanalizing a blood vessel having an occlusion in a lumen thereof. The catheter assembly includes a hub assembly, a catheter shaft including inner and outer tubular members extending distally from the hub assembly, and an expandable structure mounted on a distal portion of the catheter shaft which is configured to be actuated between a collapsed configuration and an expanded configuration by longitudinal movement of the inner tubular member relative to the outer tubular member. The catheter assembly is configured to be advanced into a subintimal space between adjacent tissue layers of a wall of the blood vessel to facilitate reentry into the blood vessel lumen by advancing a penetration member distally out of the lumen of the inner tubular member and through the tissue layer into the blood vessel lumen distal of the occlusion.