Multi-stage Balloon Catheter Anchoring for Stent Placement
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Solution Overview
Problem
The placement of stents in ostial lesions is challenging due to tapered sections in body lumens, causing standard balloon catheters to shift and misplace the stent, known as the 'watermelon seed effect', which complicates proper stent deployment.
Innovation Solution
A multi-stage balloon catheter assembly with a first balloon to secure the catheter in a non-tapered portion and a second balloon to expand the stent, using a pressure-actuated inflation valve to control fluid communication and prevent movement during stent expansion in tapered sections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a standard balloon catheter is inflated within an ostium, then the balloon can dilate the lumen and expand a stent, but the balloon interacts with the tapered portion causing the catheter to shift and the stent to be misplaced
Solution Approach 1:
The catheter is divided into multiple segments with distinct functions: a first balloon for anchoring in the non-tapered portion and a second balloon for stent expansion in the tapered portion. This segmentation allows each balloon to perform its specific function independently, preventing the watermelon seed effect while enabling accurate stent placement.
Solution Approach 2:
The first balloon is inflated in advance to anchor the catheter in the non-tapered portion of the vessel before the second balloon is inflated for stent expansion. This preliminary anchoring action prevents the catheter from shifting during the subsequent stent deployment, ensuring accurate stent placement.
2Manufacturing precision
If a single balloon is used to expand a stent in an ostium, then the stent can be deployed, but the balloon shifts laterally due to the tapered section causing misplacement
Solution Approach 1:
The deployment system is segmented into two functional components: an anchoring balloon (first balloon) and an expansion balloon (second balloon). The anchoring balloon provides stable positioning while the expansion balloon reliably deploys the stent, separating the functions to improve both precision and reliability.
Solution Approach 2:
The first balloon acts as an intermediary anchoring mechanism between the operator and the stent deployment process. By providing a stable anchor point in the non-tapered portion, it mediates the force transmission and prevents lateral shifting, ensuring reliable and accurate stent placement.
3Manufacturing precision
If fluid pressure is increased to expand the stent, then the stent can be deployed, but the catheter moves laterally in the tapered section
Solution Approach 1:
The force application is segmented into two stages: the first balloon anchors the catheter to resist lateral forces, while the second balloon applies expansion force for stent deployment. This segmentation allows high expansion force to be applied without causing lateral movement, as the anchoring balloon counteracts these forces.
Solution Approach 2:
The first balloon provides a counterbalancing anchoring force that opposes the lateral forces generated during stent expansion. By positioning the anchoring balloon in the non-tapered portion, it creates a counterweight effect that prevents the catheter from shifting laterally when expansion force is applied.
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
Ensures accurate placement and expansion of stents by anchoring the catheter with the first balloon before expanding the stent with the second balloon, minimizing lateral movement and maintaining proper positioning within the ostium.
Implementation Method 1
Fluid is provided to the first balloon to inflate the first balloon in a non-tapered portion of the body lumen. The inflated first balloon secures the catheter within the non-tapered portion of the body lumen.
Implementation Method 2
The pressure actuated inflation valve is operably coupled to the second balloon and provides fluid communication through the inflation valve to the second interior volume when a threshold fluid pressure is exceeded in the first balloon.
Implementation Method 3
Fluid is continues to be provided to the second balloon through the pressure actuated inflation valve to inflate the second balloon thereby expanding the stent.
Data Source
AI summary
A multistage balloon catheter that uses a single lumen to inflate a balloon in stages is disclosed. A fluid port provides fluid communication from an inflation lumen in the balloon catheter to the inner volume of a distal balloon. The distal balloon expands as fluid in delivered to the inner volume of the distal balloon. Once inflated, the pressure continues to rise until a threshold pressure is exceeded. A pressure sensitive inflation valve provides fluid communication into an inner volume of a second balloon disposed at least partially proximal to the distal balloon. The pressure sensitive valve allows fluid communication into the second balloon once the threshold pressure is reached in the first balloon thereby inflating the second balloon.