Ostial Stent Positioner for Accurate Artery Placement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing stent positioning devices face challenges in accurately placing the proximal end of a stent within ±2 mm of the ostial plane of an artery, especially at the aorto-ostial lesion, due to high friction and obstruction issues within the guiding catheter, limiting the use of contrast material and guide wires.
Innovation Solution
A wire-based ostial stent positioner with a short expandable cylinder and legs that can be deployed to gently engage the aortic wall, allowing for precise alignment and placement of the stent's proximal end using a guiding catheter, which includes a variable diameter slit cylinder for reduced friction and a radiopaque marker for clear visualization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a cylindrical sheath extends for the entire length of the guiding catheter, then stent positioning accuracy is improved, but friction between the sheath and catheter wall increases making operation difficult
Solution Approach 1:
The sheath is segmented into a distal positioning portion and a proximal delivery portion. The distal portion (10-20 mm) provides positioning accuracy while the proximal portion remains flexible and low-friction for easy advancement through the guiding catheter.
Solution Approach 2:
The distal portion of the sheath is constructed with different properties than the proximal portion - the distal end has increased rigidity and radiopaque markers for positioning, while the proximal portion maintains flexibility and low profile for navigation.
2Measurement precision
If a cylindrical sheath extends for the entire length of the guiding catheter, then stent positioning accuracy is improved, but the internal cross-section of the guiding catheter is substantially obstructed
Solution Approach 1:
The sheath is confined to the distal 10-20 mm of the guiding catheter rather than extending the full length. This segmentation allows the proximal 80-90% of the catheter interior to remain open for contrast injection and guide wire passage.
Solution Approach 2:
The sheath transitions from a potential full-length obstruction to a localized distal structure, changing the spatial distribution from one-dimensional full-length coverage to a concentrated three-dimensional structure at the catheter tip.
3Device complexity
If the expandable distal portion is not optimized for easy usage, then device simplicity is maintained, but ease of operation deteriorates
Solution Approach 1:
The expandable distal portion is pre-positioned within the guiding catheter before the procedure begins. The interventionalist simply needs to deploy it by inflating a balloon or releasing a constraint, eliminating complex manual manipulation.
Solution Approach 2:
Manual mechanical manipulation of the distal portion is replaced by a simple balloon inflation mechanism or constraint release system, reducing the skill level and effort required for deployment.
Data Source
AI summary
Disclosed is an ostial stent positioner that has the form of a wire for most of its length and having a short cylinder with a longitudinal slit and expandable legs situated at the positioner's distal end. The slit cylinder with its attached wire acts as an introducer sheath to introduce a stent delivery system with a stent into the artery that is to be stented. A second aspect of the present invention is a method for accurately placing a stent at the ostium of an artery that would have an ostial stenosis. Examples of such arteries that have ostial stenoses are the right and left main coronary arteries, a saphenous vein graft as used in coronary bypass surgery and the renal arteries. Also disclosed are designs for the slit cylinder that provides a variable diameter so as to fit snugly within guiding catheters having different inside diameters.