# US 9,867,724 B2 · Hollow drug-filled stent and method of forming hollow drug-filled stent > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,867,724 B2 - Document ID: US9867724B2 - Status: Granted - Kind: B2 - Application number: 14/636,371 - Filed: 2015-03-03 - Published: 2015-09-03 - Granted: 2018-01-16 - Earliest claimed: 2012-04-13 - Assignees: Medtronic Vascular, Inc. - Applicants: Medtronic Vascular, Inc. - Inventors: Ryan Bienvenu; James Mitchell; Dustin Thompson - Web page: https://patentgrep.com/patent/US9867724B2 ## CPC - A61F 2/86: Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure - A61F 2/91: made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes - A61L 31/022: {Metals or alloys} - A61L 31/16: Biologically active materials, e.g. therapeutic substances {(A61L31/047 takes precedence)} - A61L 31/18: Materials at least partially X-ray or laser opaque - A61F 2210/0076: multilayered, e.g. laminated structures - A61F 2240/001: Designing or manufacturing processes - A61F 2250/0068: the pharmaceutical product being in a reservoir - A61F 2250/0098: radio-opaque, e.g. radio-opaque markers - Y10T 29/49817: with other than ancillary treating or assembling - Y10T 29/4998: Combined manufacture including applying or shaping of fluent material - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) - A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A stent is formed from a wire having an outer member, a radiopaque member lining at least a portion of the outer member inner surface, and a lumen defined by the outer member inner surface or the radiopaque member inner surface. A substance is disposed in the lumen to be eluted through at least one opening disposed through the outer member to the lumen. The radiopaque member may be substantially continuous along the length of the wire or disposed only along portions of the wire such as crowns. In a method for making the stent, a composite wire including an outer member, a radiopaque intermediate member, and a core member is shaped into a stent pattern and processed to remove the core member and optionally portions of the radiopaque intermediate member, without damaging the outer member. ## Claims ### Claim 1 A method of forming a stent comprising the steps of: shaping a composite wire into a stent pattern, wherein the composite wire comprises an outer member, a radiopaque intermediate member, and a core member, wherein the radiopaque intermediate member is disposed between the outer member and the core member; processing the composite wire such that the core member is removed without adversely affecting the outer member, thereby leaving an outer member, the radiopaque intermediate member lining at least a portion of an inner surface of the outer member, and a lumen, at least a portion of the lumen defined by an inner surface of the radiopaque intermediate member; filling at least a portion of the lumen with a biologically or pharmacologically active substance; and providing openings through at least the outer member such that the openings extend from an outer surface of the outer member to the lumen. ### Claim 2 (depends on 1) The method of claim 1, wherein the step of processing the composite wire such that the core member is removed also comprises removing portions of the radiopaque intermediate member such that portions of the inner surface of the outer member are not lined with the radiopaque intermediate member. ### Claim 3 (depends on 2) The method of claim 2, wherein the step of shaping the composite wire into a stent form includes shaping the composite wire into a waveform including struts connected by crowns, and wherein after the step of processing the composite wire to remove the core member and portions of the radiopaque intermediate member, the radiopaque intermediate member lines the inner surface of the outer member only in crowns of the waveform. ### Claim 4 (depends on 1) The method of claim 1, wherein the biologically or pharmacologically active substance is selected from the group consisting of antineoplastic, antimitotic, antiinflammatory, antiplatelet, anticoagulant, anti fibrin, antithrombin, antiproliferative, antibiotic, antioxidant, and antiallergic substances as well as combinations thereof. ### Claim 5 (depends on 1) The method of claim 1, wherein the step of providing openings through the outer member comprises laser drilling openings through the outer member and the intermediate member. ### Claim 6 (depends on 1) The method of claim 1, wherein the step of providing openings through the outer member occurs before the step of processing the composite wire to remove the core member. ### Claim 7 (depends on 1) The method of claim 1, wherein the outer member comprises a cobalt-chromium alloy, the radiopaque intermediate member comprises a platinum-iridium alloy, the core member is selected from the group consisting of tantalum, tungsten, molybdenum, niobium, rhenium, carbon, germanium, silicon, and tantalum-tungsten alloys, and the step of removing the core member comprises exposing the core member to xenon-difluoride. ### Claim 8 (depends on 1) The method of claim 1, wherein the outer member comprises a cobalt-chromium alloy, the radiopaque intermediate member is selected from the group consisting of tantalum and tantalum-tungsten alloys, the core member comprises copper or silver, and the step of removing the core member comprises exposing the core member to nitric acid. ### Claim 9 (depends on 1) The method of claim 1, wherein the outer member comprises a cobalt-chromium alloy, the radiopaque intermediate member is selected from the group consisting of platinum-iridium alloys, tantalum, and tantalum-tungsten alloys, the core member is selected from the group consisting of zinc and magnesium, and the step of removing the core member comprises exposing the core member to water or salt water or heat to melt or sublimate the core member. ### Claim 10 (depends on 2) The method of claim 2, wherein the outer member comprises a cobalt-nickel-chromium-molybdenum alloy, the radiopaque intermediate member comprises tantalum, the core member is selected from the group consisting of rhenium, molybdenum, tungsten, and alloys thereof, and the step of removing the core member and portions of the radiopaque intermediate member comprises exposing the core member to xenon-difluoride such that the core member is etched at a faster rate than the radiopaque intermediate member. ### Claim 11 (depends on 1) The method of claim 1, further comprising the step of removing portions of the intermediate member in a separate step from the step of removing the core member. ### Claim 12 (depends on 11) The method of claim 11, wherein the step of removing the core member is a dry etch process and the step of removing portions of the radiopaque intermediate member is a selective wet etch process.