Variable-Diameter Stent Anchoring for Ductus Arteriosus Patency
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Solution Overview
Problem
Conventional stents face challenges in conformability, apposition to vessel walls, and fixing, particularly in pediatric cardiovascular applications, such as maintaining ductus arteriosus patency in newborns, with issues including stent migration, vasospasm, and difficulty in precise placement.
Innovation Solution
A stent design with variable strut lengths and diameters, ensuring a consistent radial force along the stent length, allowing for precise placement and anchoring in the ductus arteriosus without interfering with adjacent arteries, using microcatheters for delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If conventional stents are used in pediatric cardiovascular procedures, then the device can be inserted into the blood vessel, but the stent exhibits poor conformability and apposition to vessel walls
Solution Approach 1:
The stent employs variable diameter design where the first and second end sections have different diameters than the body section, allowing each portion to conform to different anatomical characteristics of the ductus arteriosus. The end sections are configured to engage with the aorta and pulmonary artery respectively, providing localized adaptation to vessel geometry while maintaining reliable apposition throughout.
2Reliability
If conventional stents are used to maintain ductus arteriosus patency, then the device can be deployed, but stent migration occurs
Solution Approach 1:
The stent features enlarged end sections that extend beyond the body section diameter to engage with the aorta and pulmonary artery. This localized diameter variation creates anchoring zones at both ends that prevent stent migration while maintaining stable positioning within the ductus arteriosus, resolving the contradiction between patency maintenance and position stability.
3Force
If a uniform diameter stent is used, then the device structure is simple, but the stent cannot provide consistent radial force in vessels with varying diameter
Solution Approach 1:
The stent employs variable diameter design where the first end section has a larger diameter than the body section to engage the aorta, the body section has an intermediate diameter for the ductus arteriosus, and the second end section has a larger diameter to engage the pulmonary artery. This localized diameter variation enables consistent radial force delivery across vessels with varying diameter while managing structural complexity through a systematic design approach.
4Reliability
If conventional stents are used in newborns, then the device can treat the condition, but the stent interferes with adjacent arteries
Solution Approach 1:
The stent is designed with variable diameter where the body section fits within the ductus arteriosus while the end sections with larger diameters engage with the aorta and pulmonary artery. This localized diameter differentiation allows the stent to treat ductus arteriosus effectively while the enlarged ends prevent interference with adjacent arteries by providing stable anchoring zones that distribute mechanical stress away from critical vascular structures.
Data Source
AI summary
Described herein are variable diameter stents for insertion into a blood vessel lumen to provide a generally radially outward force on the blood vessel lumen. The stent may comprise a first end section comprising a first plurality of struts defining a first variable diameter; a second end section comprising a second plurality of struts defining a second variable diameter; a body section extending between the first end section and the second end section and comprising a third plurality of struts; and a device lumen extending through the first end section, the body section, and the second end section. In an expanded configuration, a first subset of the first plurality of struts is increased in length from the body section towards a proximal face, and a first subset of the second plurality of struts is increased in length from the body section towards a distal face.