Aspiration Catheter Reverse-Flow Cycling for Corking Control
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Solution Overview
Problem
Current aspiration catheters face challenges such as clot deformation leading to corking, incomplete clot removal, increased procedure time, and inability to confirm thrombus capture within the sterile field, with low first-pass recanalization rates and risks of clot ejection causing further vessel blockage.
Innovation Solution
An aspiration thrombectomy system with a mechanism to halt vacuum at the distal end, push the thrombus distally, and reapply vacuum, using a column shift mechanism to control vacuum and vent valves to prevent forward flow, ensuring complete clot removal and confirmation of recanalization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional aspiration catheters are used to remove clots, then clot removal is attempted, but the thrombus becomes lodged at the distal opening of the catheter (corking), preventing complete removal
Solution Approach 1:
The patent applies reverse flow mechanism where fluid is first pushed distally to detach the corked thrombus from the catheter opening, then vacuum is reapplied to aspirate the detached thrombus. This inversion of the normal aspiration sequence resolves the corking problem by preventing the thrombus from becoming lodged at the distal opening.
Solution Approach 2:
The system employs periodic cycling between vacuum aspiration and reverse flow push phases. This periodic action allows the thrombus to be alternately aspirated and detached, preventing permanent lodging at the catheter opening and enabling complete removal through multiple cycles.
2Ease of operation
If vacuum is applied to aspirate the clot, then the clot is drawn into the catheter, but reversing suction to eject the clot causes it to move further distally and potentially burst the vessel
Solution Approach 1:
The patent introduces a controlled reverse flow mechanism as an intermediary step between aspiration and clot ejection. Instead of directly reversing suction to forcefully eject the clot, the system uses controlled reverse flow to push the clot distally in a controlled manner, reducing the risk of uncontrolled movement and vessel damage.
Solution Approach 2:
The system dynamically changes the pressure parameters by switching between negative pressure (vacuum aspiration) and positive pressure (reverse flow push). This parameter change allows controlled manipulation of the thrombus position and extraction without causing harmful effects to the vessel.
3Adaptability or versatility
If the aspiration catheter is threaded through a balloon guide catheter, then access to the clot is achieved, but the procedure time increases and first-pass recanalization rate remains low
Solution Approach 1:
The patent employs dynamic control of the balloon inflation/deflation sequence coordinated with aspiration and reverse flow phases. The balloon is dynamically adjusted during the procedure to optimize thrombus capture and extraction efficiency, enabling complete removal in a single pass and reducing overall procedure time.
4Productivity
If continuous vacuum is applied during aspiration, then clot is drawn into the catheter, but forward flow of fluid exits the distal end and can carry clot fragments further distally
Solution Approach 1:
The system uses periodic cycling between vacuum aspiration and reverse flow push phases. During the reverse flow phase, the vacuum is temporarily stopped and reverse flow is applied to push fluid and any loose clot fragments distally in a controlled manner, preventing them from being carried further into the vasculature during the aspiration phase.
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 system enhances first-pass recanalization rates, prevents clot obstruction, and allows for real-time confirmation of thrombus removal, reducing procedure time and risks, thereby improving surgical efficacy and safety.
Implementation Method 1
a source of vacuum, e.g., an aspiration or vacuum catheter, upstream of the clot and drawing the clot into or against the distal end of the catheter
Implementation Method 2
push the thrombus distally, and reapply vacuum, using a column shift mechanism to control vacuum and vent valves
Data Source
AI summary
A clot removal system comprises a catheter, a vacuum source, and a controller. The catheter comprises a proximal end, a distal end, and controller operating parameters and defines a lumen configured to be filled with a liquid column having a proximal portion. The vacuum source is configured to supply vacuum. The controller is configured to carry out a control pattern of turning on and off the vacuum based upon the controller operating parameters and is configured to receive the controller operating parameters in an automatic response to the catheter being operatively connected to at least one of the vacuum source and the controller and, responsive to the connection, to carry out the control pattern to change a level of vacuum at the distal end of the catheter.