Laterally Deployable Catheter Re-Entry Mechanism
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Solution Overview
Problem
Current catheter devices face challenges in effectively re-entering the true lumen of an artery from a subintimal space, particularly in bypassing chronic total occlusions, where guidewires often become entrapped, and existing solutions require complex procedures and additional tools like IVUS for accurate placement.
Innovation Solution
A catheter device with a laterally deployable member, comprising a lubricious core member, a braided layer, and an outer layer, allowing for advancement of a guidewire into the true lumen without a lubricious liner, and featuring an elastic or superelastic needle biased to a curved configuration with imageable markers for precise orientation, enabling the re-entry into the true lumen and subsequent bypass of obstructions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a guidewire is advanced around an obstructive lesion, then the guidewire can bypass the obstruction, but the distal portion of the guidewire becomes entrapped in the artery wall (subintimal space)
Solution Approach 1:
A catheter with a laterally deployable member serves as an intermediary device to guide the guidewire from the subintimal space back into the true lumen. The catheter body is positioned in the subintimal space, and the laterally deployable member extends through the artery wall to provide a pathway for guidewire re-entry into the true lumen, thus mediating the transition from incorrect to correct positioning.
Solution Approach 2:
The catheter is advanced into the subintimal space before attempting guidewire re-entry, preparing the pathway in advance. The laterally deployable member is positioned and oriented beforehand using imageable markers, ensuring that the guidewire will be directed correctly into the true lumen when advanced through the catheter.
2Measurement precision
If imageable markers are added to the catheter for precise orientation, then the directional control of the laterally deployable member is improved, but the device complexity increases
Solution Approach 1:
Imageable markers (such as radiopaque or fluoroscopic markers) are incorporated into the catheter structure to provide visual indication of the catheter's orientation and position. These markers change appearance or become visible under imaging modalities (X-ray, fluoroscopy), allowing the operator to accurately determine the directional orientation of the laterally deployable member without adding complex mechanical orientation mechanisms.
3Object-affected harmful factors
If the catheter diameter is reduced to minimize patient trauma, then the ease of insertion is improved, but the torque transmission capability deteriorates
Solution Approach 1:
The catheter is constructed using composite materials and a multi-layer structure (core member, braided layer, outer layer) that provides high torque transmission capability relative to its small diameter. The braided layer in particular contributes to torque resistance while maintaining flexibility, allowing the catheter to be both small (reducing patient trauma) and mechanically robust (maintaining torque transmission for precise positioning and laterally deployable member control).
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 catheter device allows for efficient re-entry of guidewires into the true lumen, reducing the risk of subintimal entrapment and enabling effective bypass of obstructions with reduced procedural complexity and patient trauma, while maintaining torque transmission and flexibility.
Implementation Method 1
the laterally deployable member may comprise an elastic or superelastic needle biased to a curved configuration
Implementation Method 2
the laterally deployable member may comprise an elastic or superelastic needle biased to a curved configuration
Implementation Method 3
the core member is formed of material that is sufficiently lubricious to allow a guidewire or other member to advance through the lumen of the core member without the need for placement of a lubricious liner within the lumen
Data Source
AI summary
Catheter devices having low profile shafts and laterally deployable members (e.g., cannulas, needles, etc.) that may be extended or advanced laterally from the catheter shaft. Also disclosed are methods for bypassing a vascular obstruction (e.g., a chronic total occlusion or other full or partial obstruction) wherein a guidewire is entrapped in a subintimal space adjacent to the obstruction. A catheter of the foregoing character is advanced over the entrapped guidewire and into the subintimal space. The laterally deployable member is then advanced or extended from the subintimal space back into the true lumen of the blood vessel distal to the obstruction. A second guidewire is then advanced through or along the laterally deployable member. The catheter and first guidewire are then removed and one or more working device(s) (balloons, atherectomy devices, setnts, etc.) is/are advanced over the second guidewire and used to establish a subintimal bypass channel through which blood may flow around the obstruction.