STENT WITH COATED STRUTS
A medical stent may include a tubular support structure including a plurality of struts defining a plurality of cells disposed between the plurality of struts. A polymeric coating may be disposed over the tubular support structure such that a first portion of the plurality of cells are closed by the polymeric coating in a first region of the tubular support structure and a second portion of the plurality of cells in a second region of the tubular support structure remain open to fluid flow and/or tissue ingrowth therethrough. The struts in the first region of the tubular support structure and the struts in the second region of the tubular support structure may be at least partially covered by the polymeric coating.
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This application is a continuation of U.S. Application Serial No. 16/407,924, filed May 9, 2019, which is a continuation of U.S. Application Serial No. 15/260,582, filed Sep. 9, 2016, now U.S. Pat. No. 10,314,726, which claims priority to U.S. Provisional Application Serial No. 62/216,573, filed Sep. 10, 2015, the entire disclosures of which are incorporated herein by reference.
TECHNICAL FIELDThe disclosure is directed to an endoprosthesis, such as a stent. More particularly, the disclosure is directed to a stent that includes cushioned struts that reduce irritation while permitting fluid flow.
BACKGROUNDAn endoprosthesis may be configured to be positioned in a body lumen for a variety of medical applications. For example, an endoprosthesis may be used to treat a stenosis in a blood vessel, used to maintain a fluid opening or pathway in the vascular, urinary, biliary, tracheobronchial, esophageal or renal tracts, or to position a device such as an artificial valve or filter within a body lumen, in some instances. In some instances, an endoprosthesis may be used within an organ such as the pancreas, in the biliary system or in the pulmonary system. In some cases, there can be a desire to retain patency within a main lumen while not blocking fluid flow from side branches feeding into or out of the main lumen. In some cases, there can be a desire to provide endoprostheses that exhibit anti-migration features, while reducing the trauma to the body lumen of the patient if removal of the endoprosthesis is desired. In some cases, there can be a desire to avoid tissue irritation that can occur in response to a bare metal stent or stent component contacting tissue.
Accordingly, it is desirable to provide endoprostheses that can retain patency within a main lumen within the body structure while not blocking fluid flow from side branches within the body structure, while providing anti-migration features, and/or while avoiding tissue irritation.
BRIEF SUMMARYThe disclosure is directed to several alternative designs, materials and methods of manufacturing medical device structures and assemblies, and uses thereof.
A medical stent is disclosed. The medical stent includes a tubular support structure including a plurality of struts. The plurality of struts define a plurality of cells disposed between the plurality of struts. A polymeric coating is disposed over the tubular support structure such that a first portion of the plurality of cells are closed by the polymeric coating in a first region of the tubular support structure and a second portion of the plurality of cells in a second region of the tubular support structure remain open to fluid flow therethrough. The struts in the first region of the tubular support structure and the struts in the second region of the tubular support structure are at least partially covered by the polymeric coating.
Alternatively or additionally to any of the embodiments above, the struts in the first region of the tubular support structure and the struts in the second region of the tubular support structure are encapsulated by the polymeric coating.
Alternatively or additionally to any of the embodiments above, the polymeric coating is formed by covering the tubular support structure with the polymeric coating and subsequently removing part of the polymeric coating spanning one or more of the plurality of cells within the second region of the tubular support structure.
Alternatively or additionally to any of the embodiments above, the polymeric coating is formed by encapsulating the plurality of struts and subsequently coating at least one or more of the plurality of cells within the first region of the tubular support structure.
Alternatively or additionally to any of the embodiments above, the polymeric coating is formed by placing the tubular support structure over a mandrel and then spray coating the tubular support structure, wherein the mandrel includes raised portions contacting the tubular support structure within the first region and portions spaced from the tubular support structure within the second region.
Alternatively or additionally to any of the embodiments above, the first region of the tubular support structure, in which the first portion of the plurality of cells are covered by the polymeric coating, includes one or more distinct areas of the tubular support structure.
Alternatively or additionally to any of the embodiments above, the second region of the tubular support structure, in which the second portion of the plurality of cells remain open to fluid flow therethrough, includes one or more distinct areas of the tubular support structure.
Alternatively or additionally to any of the embodiments above, the second region of the tubular support structure, in which the second portion of the plurality of cells remain open to fluid flow therethrough, spans over half of the tubular support structure.
Alternatively or additionally to any of the embodiments above, the polymeric coating comprises polyurethane or silicone.
Alternatively or additionally to any of the embodiments above, the medical stent comprises a pulmonary stent.
Alternatively or additionally to any of the embodiments above, the medical stent comprises an esophageal stent.
Alternatively or additionally to any of the embodiments above, the medical stent comprises a pancreatic stent.
A medical stent is disclosed. The medical stent includes a metallic support structure including a plurality of struts. The plurality of struts together defining a shape of the metallic support structure. A cushioning material is disposed on at least some of the plurality of struts. At least some of the inter-strut spaces adjacent struts bearing the cushioning material are open to fluid flow therethrough.
Alternatively or additionally to any of the embodiments above, the medical stent further comprises a polymeric layer spanning at least some of the inter-strut spaces that are different inter-strut spaces than those that are open to fluid flow.
Alternatively or additionally to any of the embodiments above, the cushioning material comprises a polymeric material, and the polymeric layer comprises the same polymeric material.
Alternatively or additionally to any of the embodiments above, the cushioning material comprises polyurethane or silicone.
A method of manufacturing a medical stent is disclosed. The method comprises coating a tubular support structure including a plurality of struts defining a plurality of inter-strut spaces with a polymeric coating such that the plurality of struts and the plurality of inter-strut spaces are covered with the polymeric coating; and selectively removing the polymeric coating from at least some of the inter-strut spaces such that a portion of at least some of the inter-strut spaces are opened but the plurality of struts remain covered by the polymeric coating.
Alternatively or additionally to any of the embodiments above, selectively removing the polymeric coating comprises using laser ablation.
Alternatively or additionally to any of the embodiments above, the polymeric coating comprises polyurethane or silicone.
Alternatively or additionally to any of the embodiments above, coating a tubular support structure comprises spray coating a tubular support structure.
The above summary of some example embodiments is not intended to describe each disclosed embodiment or every implementation of the aspects of the disclosure.
The aspects of the disclosure may be more completely understood in consideration of the following detailed description of various embodiments in connection with the accompanying drawings, in which:
While the aspects of the disclosure are amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit aspects of the disclosure to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.
DETAILED DESCRIPTIONFor the following defined terms, these definitions shall be applied, unless a different definition is given in the claims or elsewhere in this specification.
Definitions of certain terms are provided below and shall be applied, unless a different definition is given in the claims or elsewhere in this specification.
All numeric values are herein assumed to be modified by the term “about”, whether or not explicitly indicated. The term “about” generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (i.e., having the same function or result). In many instances, the term “about” may be indicative as including numbers that are rounded to the nearest significant figure.
The recitation of numerical ranges by endpoints includes all numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).
Although some suitable dimensions, ranges and/or values pertaining to various components, features and/or specifications are disclosed, one of skill in the art, incited by the present disclosure, would understand desired dimensions, ranges and/or values may deviate from those expressly disclosed.
As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include or otherwise refer to singular as well as plural referents, unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed to include “and/or,” unless the content clearly dictates otherwise.
The following detailed description should be read with reference to the drawings in which similar elements in different drawings are numbered the same. The detailed description and the drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the disclosure. The illustrative embodiments depicted are intended only as exemplary. Selected features of any illustrative embodiment may be incorporated into an additional embodiment unless clearly stated to the contrary.
In some cases, as illustrated, at least part of the endoprosthesis 10 may include a polymeric coating 22. The tubular support structure 1 may be considered as including a first region 24 in which the polymeric coating 22 spans or at least substantially covers the cells 20 that are within the first region 24. The tubular support structure 1 also includes a second region 26 in which the polymeric coating 22 does not span or completely cover the cells 20 that are within the second region 26 and thus the cells 20 within the second region 26 are configured to permit fluid flow therethrough and/or tissue ingrowth once the endoprosthesis 10 has been implanted. As illustrated, the second region 26 may be seen to include a first area 26a that is located near the first end 12 of the endoprosthesis 10 and a second area 26b that is located near the second end 14 of the endoprosthesis 10. As can be seen, the polymeric coating 22 covers the struts 3 within the first region 24 and the second region 26. In some cases, the polymeric coating 22 may be considered as encapsulating the struts 3. In some instances, the polymeric coating 22 encapsulating or otherwise covering the struts 3 may be considered as a cushioning material that can reduce tissue irritation once implanted. In some cases, the polymeric coating 22 may include silicone or polyurethane, although other polymeric materials are contemplated.
In
The selective polymeric coatings shown in
In
Once the endoprosthesis 10, 30, 32, 50, 80 has been formed as discussed herein, it may be implanted as desired.
In some instances, the main pancreatic duct 13 may become narrowed or inflamed, and there may be a desire to maintain the patency of the main pancreatic duct 13. In some embodiments, as illustrated, an endoprosthesis 126 may be deployed within the main pancreatic duct 13. The endoprosthesis 126 may be implanted in any suitable manner, including reaching the interior of the main pancreatic duct 13 from the interior of the duodenum 114. It will be appreciated that while the endoprosthesis 126 is illustrated and described herein as a pancreatic stent 126, the endoprosthesis 126 may be deployed in a variety of other bodily lumens, including but not limited to the vascular, urinary, biliary, tracheobronchial, esophageal or renal tracts. Although illustrated as a stent, the endoprosthesis 126 may be any of a number of devices that may be introduced endoscopically, subcutaneously, percutaneously or surgically to be positioned within an organ, tissue, or lumen, such as a heart, artery, vein, urethra, esophagus, trachea, bronchus, bile duct, or the like.
The polymer coating 22, 62, 84 may be formed of any suitable polymeric material. In some embodiments, the polymer coating 22, 62, 84 is formed of a biocompatible material such as polyurethane or silicone. Other suitable polymers include but are not limited to polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, for example, DELRIN® available from DuPont), polyether block ester, polyurethane (for example, Polyurethane 85A), polypropylene (PP), polyvinylchloride (PVC), polyether-ester (for example, ARNITEL® available from DSM Engineering Plastics), ether or ester based copolymers (for example, butylene/poly(alkylene ether) phthalate and/or other polyester elastomers such as HYTREL® available from DuPont), polyamide (for example, DURETHAN® available from Bayer or CRISTAMID® available from Elf Atochem), elastomeric polyamides, block polyamide/ethers, polyether block amide (PEBA, for example available under the trade name PEBAX®), ethylene vinyl acetate copolymers (EVA), silicones, polyethylene (PE), Marlex high-density polyethylene, Marlex low-density polyethylene, linear low density polyethylene (for example REXELL®), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), poly paraphenylene terephthalamide (for example, KEVLAR®), polysulfone, nylon, nylon-12 (such as GRILAMID® available from EMS American Grilon), perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (for example, SIBS and/or SIBS 50A), polycarbonates, ionomers, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers thereof, polymer/metal composites, and the like
In some embodiments, the tubular support structure 1, 60, 82 may be formed from any desired material, such as a biocompatible material including biostable, bioabsorbable, biodegradable or bioerodible materials. For instance, the tubular support structure 1, 60, 82 may be formed of a metallic material. Some suitable metallic materials include, but are not necessarily limited to, stainless steel, tantalum, tungsten, nickel-titanium alloys such as those possessing shape memory properties commonly referred to as nitinol, nickel-chromium alloys, nickel-chromium-iron alloys, cobalt-chromium-nickel alloys, or other suitable metals, or combinations or alloys thereof.
In some embodiments, the tubular support structure 1, 60, 82 may include one or more metals. Some examples of suitable metals and metal alloys include stainless steel, such as 304V, 304L, and 31LV stainless steel; mild steel; nickel-titanium alloy such as linear-elastic and/or super-elastic nitinol; other nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625 such as INCONEL® 625, UNS: N06022 such as HASTELLOY® C-22®, UNS: N10276 such as HASTELLOY® C276®, other HASTELLOY® alloys, and the like), nickel-copper alloys (e.g., UNS: N04400 such as MONEL® 400, NICKELVAC® 400, NICORROS® 400, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035 such as MP35-N® and the like), nickel-molybdenum alloys (e.g., UNS: N10665 such as HASTELLOY® ALLOY B2®), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, and the like; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS: R30003 such as ELGILOY®, PHYNOX®, and the like); platinum enriched stainless steel; titanium; combinations thereof; and the like; or any other suitable material.
Those skilled in the art will recognize that aspects of the present disclosure may be manifested in a variety of forms other than the specific embodiments described and contemplated herein. Accordingly, departure in form and detail may be made without departing from the scope of the present disclosure as described in the appended claims.
Claims
1. A medical stent comprising:
- a tubular support structure including a plurality of struts, the plurality of struts defining a plurality of cells disposed between the plurality of struts; and
- a polymeric coating disposed over the tubular support structure defining a plurality of closed cells that are completely covered by the polymeric coating, and a plurality of open cells that are open to allow fluid flow or tissue ingrowth therethrough;
- wherein the polymeric coating extends over and laterally beyond each of the plurality of struts and partially into each of the plurality of open cells.
2. The medical stent of claim 1, wherein the plurality of struts defining the plurality of closed cells and the plurality of struts defining the plurality of open cells are encapsulated by the polymeric coating.
3. The medical stent of claim 1, wherein the polymeric coating is formed by covering the tubular support structure with the polymeric coating and subsequently removing part of the polymeric coating spanning a plurality of the plurality of cells to create the plurality of open cells.
4. The medical stent of claim 1, wherein the polymeric coating is formed by encapsulating the plurality of struts and subsequently coating some of the plurality of cells to create the plurality of closed cells.
5. The medical stent of claim 1, wherein the polymeric coating is formed by placing the tubular support structure over a mandrel and then spray coating the tubular support structure, wherein the mandrel includes raised portions contacting the tubular support structure to define the plurality of closed cells and portions spaced from the tubular support structure to define the plurality of open cells.
6. The medical stent of claim 1, wherein the plurality of closed cells are located in at least a first region of the tubular support structure, and the plurality of open cells are located in at least a second region of the tubular support structure.
7. The medical stent of claim 1, wherein the plurality of closed cells are located in at least first and second regions of the tubular support structure, and the plurality of open cells are located in at least third and fourth regions of the tubular support structure, wherein the third region is disposed between the first and second regions.
8. The medical stent of claim 7, wherein the fourth region is adjacent the second region.
9. The medical stent of claim 7, further comprising a fifth region of closed cells disposed adjacent the fourth region.
10. The medical stent of claim 1, wherein the tubular support structure is a woven, braided or knitted structure.
11. The medical stent of claim 1, wherein some of the plurality of closed cells are adjacent to some of the plurality of open cells, and some of the plurality of closed cells are adjacent to only other closed cells.
12. The medical stent of claim 1, wherein each of the plurality of closed cells is adjacent to at least one of the plurality of open cells.
13. The medical stent of claim 1, wherein the polymeric coating comprises polyurethane or silicone.
14. A medical stent comprising:
- a metallic support structure including a plurality of struts defining inter-strut spaces therebetween, the plurality of struts together defining a shape of the metallic support structure; and
- a cushioning material encapsulating at least some of the plurality of struts;
- wherein the cushioning material extends laterally beyond the plurality of struts and partially into at least some of the inter-strut spaces adjacent struts encapsulated by the cushioning material.
15. The medical stent of claim 14, further comprising a polymeric layer completely spanning at least some of the inter-strut spaces.
16. The medical stent of claim 15, wherein the cushioning material comprises a first polymeric material, and the polymeric layer comprises the first polymeric material.
17. The medical stent of claim 14, wherein the cushioning material comprises polyurethane or silicone.
18. A medical stent comprising:
- a tubular support structure including a plurality of struts, the plurality of struts defining a plurality of cells disposed between the plurality of struts, each of the cells extending from an outer surface of the tubular support structure to an inner surface of the tubular support structure; and
- a polymeric coating coated onto the plurality of struts of the tubular support structure such that some of the plurality of cells are closed by the polymeric coating and some of the plurality of cells remain open to fluid flow or tissue ingrowth therethrough;
- wherein at least some of the plurality of struts coated with the polymeric coating extend between adjacent open cells.
19. The medical stent of claim 18, wherein the polymeric coating extends laterally beyond the plurality of struts coated with the polymeric coating and partially into the open cells.
20. The medical stent of claim 18, wherein the plurality of struts are encapsulated by the polymeric coating.
Type: Application
Filed: Apr 21, 2023
Publication Date: Aug 10, 2023
Applicant: BOSTON SCIENTIFIC SCIMED, INC. (Maple Grove, MN)
Inventors: Matthew B. Hollyer (Williamstown, VT), Man Minh Nguyen (Harvard, MA), Sean P. Fleury (Brighton, MA), Jason Weiner (Grafton, MA)
Application Number: 18/305,192