Stents having protruding drug-delivery features and associated systems and methods
Inventors
Fulkerson, John • Rizk, Isa • Mustapha, Jihad Ali • Jimenez, Jr., Teodoro S.
Assignees
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Publication Number
US-10172729-B2
Publication Date
2019-01-08
Expiration Date
Abstract
Expandable elements having drug-delivery features and associated systems and methods are disclosed herein. In one embodiment, a drug-eluting stent includes a radially expandable cylindrical frame having a plurality of struts. The frame is transformable between a low-profile delivery state and an expanded deployed state. A plurality of drug-delivery features are carried by one of the struts and configured to deliver a drug to a treatment site within the patient or piercing through the tissue wall to break the constricting of the vessel wall inwardly. When the frame is in the expanded state within a body lumen of the patient, the drug-delivery features extend radially outwardly away from the strut and are configured to engage and, in some arrangements, pass through a wall of the body lumen.
Core Innovation
The invention concerns expandable drug-eluting stents having a radially expandable cylindrical frame with struts and protruding features carried by the struts. The stent is configured to self-expand from a low-profile delivery state to an expanded deployed state, and the frame is collapsible from the deployed state to a delivery state for retraction within a catheter and withdrawal from the body lumen of a patient. A mechanical actuation mechanism expands the stent so that each protruding feature extends in a direction substantially parallel to a longitudinal axis of the frame and presents a terminal end extending radially outwardly away from the frame.
The terminal end is positioned entirely distal to the first portion and is configured to pierce through a wall of the body lumen in the expanded state. The expandable stent and protruding features are used to engage and, in some arrangements, pierce the body lumen wall for drug delivery. The described drug-delivery mechanism is associated with delivering drugs to vessel wall layers, including intima, neointima, internal elastic lamina (IEL), external elastic lamina (EEL), media, and adventitia.
Embodiments include integrally formed drug-delivery protruding features, or discrete protruding features, and configurations with drug-eluting coatings or drug reservoirs with selective release. Some embodiments include recessed or concealed drug-delivery features to reduce premature drug loss. The stent system can include intravascular catheter delivery, and can include self-expansion or balloon actuation, and optional covered or mesh barrier structures to manage blood flow and debris.
Claims Coverage
The partial content provides two independent method claims for treating a human patient, grounded on intravascular delivery of a radially expandable cylindrical, self-expanding frame with struts and protruding features that are mechanically actuated to extend and pierce the body lumen wall. Across the independent claims and listed dependents, the main inventive features are the two-part geometry and axial-to-radial extension behavior of the protruding features, the piercing terminal end positioning distal to the longitudinal extension portion, and the collapsibility for catheter-based retraction; additional claim coverage includes optional drug delivery from the protruding features and association of first and second lumen portions with occlusion/intima versus media/adventitia.
Mechanically actuated self-expanding stent with two-part protruding features for lumen-wall piercing
A radially expandable cylindrical frame having struts and a lumen providing a fluid pathway along a longitudinal axis, where protruding features are carried by the struts; the stent self-expands from a low-profile delivery state to an expanded deployed state and is expanded with a mechanical actuation mechanism such that a first portion of each protruding feature extends substantially parallel to the longitudinal axis and a second portion forms a terminal end that extends radially outward away from the frame, is positioned entirely distal to the first portion, and pierces through a wall of the body lumen; the frame is collapsible from the deployed state to the delivery state to be retracted within a catheter and withdrawn from the body lumen.
Protruding feature geometry with terminal end distal to the longitudinal portion and lumen-wall piercing
A radially expandable cylindrical frame having struts and a lumen providing a fluid pathway along a longitudinal axis, where each protruding feature comprises a first portion deployable to extend from the frame in a direction substantially parallel to the longitudinal axis and a second portion that forms a terminal end, deployable to extend radially outwardly away from the frame, and positioned entirely distal to the first portion; the stent self-expands from a low-profile delivery state to an expanded deployed state and is expanded with a mechanical actuation mechanism such that the second portion of each protruding feature pierces through a wall of the body lumen; the frame is collapsible from the deployed state to the delivery state to be retracted within a catheter and withdrawn from the body lumen.
Drug delivery from protruding features
Delivering a drug to the patient from protruding features.
Integrally formed reservoirs and/or drug-carrying coating to prevent clotting and/or occlusion
Protruding features include integrally formed reservoirs and/or the protruding features, the stent, or both are coated with a drug-carrying substrate to deliver drugs to the patient to prevent clotting and/or occlusion of the stent.
First and second lumen portions associated with occlusion/intima and media/adventitia
Characterizing a first portion of a body lumen as an occlusion and/or intima, and a second portion of the body lumen as a media and/or adventitia.
Overall claim coverage centers on a self-expanding radially expandable cylindrical stent with struts and mechanically actuated protruding features that extend parallel to the longitudinal axis and present terminal ends positioned distal to that first portion to pierce the body lumen wall, together with frame collapsibility for catheter retraction and withdrawal. The additional coverage explicitly adds optional drug delivery from the protruding features, including integrally formed reservoirs and/or drug-carrying substrates to prevent clotting and/or occlusion, and optionally characterizes lumen regions as occlusion/intima versus media/adventitia.
Stated Advantages
Delivers drugs to vessel wall layers by piercing through the wall of the body lumen, addressing drug contact and penetration limitations of conventional approaches.
Helps prevent clotting and/or occlusion of the stent.
Documented Applications
Treating a human patient with a stent at a target treatment site within a body lumen by intravascularly delivering a self-expanding stent and mechanically actuating protruding features to pierce through a wall of the body lumen.
Drug-eluting treatment associated with delivering drugs to vessel wall layers such as intima, neointima, IEL, EEL, media, and adventitia.
Histology evaluation of protrusion shapes (sharpened/tapered, square, round) in human cadaver vessels near atherosclerotic lesions and calcification.
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