Uncaging stent
Inventors
Sirhan, Motasim • Yan, John • Bhat, Vinayak • Paraschac, Joseph • Cryer, Brett • Serna, Benjamyn
Assignees
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Publication Number
US-12011378-B2
Publication Date
2024-06-18
Expiration Date
Abstract
A stent (scaffold) or other luminal prosthesis comprising circumferential structural elements which provide high strength after deployment and allows for scaffold to uncage, and/or allow for scaffold or luminal expansion thereafter. The circumferential scaffold is typically formed from non-degradable material and will be modified to expand and/or uncage after deployment.
Core Innovation
The invention relates to an endoluminal prosthesis having a scaffold with a tubular body comprising a plurality of circumferential rings patterned from a non-degradable material. The scaffold is configured to expand from a crimped configuration to an expanded configuration, and at least some circumferential rings comprise struts joined by crowns. At least some circumferential rings are axially joined to adjacent circumferential rings, enabling an expandable tubular scaffold architecture.
At least some circumferential rings have at least two separation regions, where the separation regions are a pre-formed break or gap in a strut. During expansion, the separation regions are immobilized, but after expansion in a physiologic environment they are configured to move apart to form discontinuities in the plurality of circumferential rings. After the discontinuities are formed, the scaffold circumferentially separates into two to five separate axially linked segments, with intact axial links between adjacent circumferential rings in each segment.
The disclosure further describes biologically active agents incorporated in the device body, including anti-proliferative, anti-mitotic, cytostatic, and anti-migratory drugs, with mTOR inhibitors such as sirolimus, rapamycin, and everolimus derivatives. It also describes coating and bonding options for immobilizing and managing the separation regions during expansion and enabling the formation and evolution of discontinuities, including degradable and non-degradable materials, polymer coating options, adhesives, sealants, or sleeves.
The document reports mechanical and functional evaluation related to discontinuity formation and scaffold behavior, including finite element analysis and mechanical testing around discontinuities. It describes embodiments in which discontinuities are formed after expansion and evaluates resulting structural behavior and outcomes such as vasomotion evaluation and implantation-related assessment.
Claims Coverage
The independent claim defines the core prosthesis architecture with expandable circumferential rings, pre-formed strut separation regions that are immobilized during expansion but move apart after expansion to create discontinuities, and a post-discontinuity circumferential separation into two to five axially linked segments. Dependent claims further specify separation-line patterns and extent, lock-and-key junction structure, dimensional relationships for lock-and-key engagement, and optional coating and material selections.
Expandable tubular scaffold of non-degradable circumferential rings with struts and crowns
A scaffold having a tubular body comprising a plurality of circumferential rings patterned from a non-degradable material, configured to expand from a crimped configuration to an expanded configuration, wherein at least some circumferential rings comprise struts joined by crowns.
Axial joining between adjacent circumferential rings
At least some of the plurality of circumferential rings are axially joined to adjacent circumferential rings.
Pre-formed strut separation regions immobilized during expansion but configured to form discontinuities after expansion
At least some of the plurality of circumferential rings have at least two separation regions, the separation regions being a pre-formed break or gap in a strut, wherein the separation regions are immobilized during expansion but configured to move apart after expansion in a physiologic environment to form discontinuities in the plurality of circumferential rings.
Circumferential separation into two to five axially linked segments after discontinuities are formed
The scaffold is configured to circumferentially separate into two to five separate axially linked segments extending from one end of the scaffold to the other end of the scaffold after all discontinuities are formed, the segments having at least some intact axial links between adjacent circumferential rings in each segment.
Spiral/helical separation-line extent
A spiral separation line forming a helical pattern spanning from a partial turn to completion of 2.5 turns along the scaffold length.
Lock-and-key junction at separation regions
At least one separation region has a lock-and-key junction.
Dimensional constraints for lock-and-key engagement relative to strut width
A male portion engages a slot or channel between two arms of a female portion, wherein the lengths of the male portion and the female slot or channel are greater than the width of the strut containing the male and female portions.
Biodegradable polymer and/or drug-containing coating
A coating includes at least one biodegradable polymer, at least one drug, or a combination of both.
Selected non-degradable metal or alloy scaffold materials
A metal or metal alloy selected from stainless steel, cobalt alloy, cobalt chrome, platinum, platinum iridium, platinum chromium, platinum rhodium, or nickel titanium.
Overall, the claim set centers on an expandable non-degradable tubular scaffold of circumferential rings having pre-formed strut separation regions that are immobilized during expansion and then move apart in a physiologic environment to create discontinuities. After discontinuity formation, the scaffold circumferentially separates into two to five axially linked segments while maintaining intact axial links, with dependent claims further narrowing separation geometry and optionally specifying coatings and scaffold metal or alloy selections.
Stated Advantages
Increased composite compliance and enablement of further expansion after discontinuities are formed.
Reduced inflammation and SMC proliferation, with neointimal hyperplasia minimization described as a design goal.
Increase radial compliance by forming discontinuities in the circumferential rings after expansion.
Reduce hoop/strength locally in regions associated with discontinuity formation.
Enable uncaging and further expansion with dynamic remodeling behavior in a physiologic environment.
Enable dynamic expansion and contraction with vasomotion, including lumen area changes over time.
Improved vessel accommodation via reduced compliance mismatch, as described in the disclosure.
Fatigue resistance over time, as described in the disclosure.
Improved crush-strength behavior over time, as described in the disclosure.
Documented Applications
Endoluminal prosthesis deployment in a physiologic environment to enable uncaging behavior, including vaso-motion, vaso-dilation, and vaso-constriction related behavior while maintaining axial support.
Drug-eluting endoluminal prosthesis embodiments that include mTOR inhibitors such as rapamycin, everolimus, and derivatives.
Endoluminal prosthesis use in a physiologic environment, including behavior during dynamic expansion and contraction with vasomotion.
Valve replacement or repair using an endoluminal prosthesis supporting an annulus, with embodiments that can include a valve and skirt/pouch for sealing.
Directional vaso-motion and vaso-dilation behavior associated with the scaffold and uncaging/discontinuities in a physiologic environment [procedural detail omitted for safety].
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