COATED MEDICAL DEVICES AND METHODS OF MAKING AND USING SAME

• US 20140277400A1
• Filed: 03/15/2013
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Muri, John, Schuman, Victoria, Sheu, Min-Shyan, Wainwright, John, Mendelson, Todd, Haggstrom, Kurt, Ma, Xiaodong, Molaei, Masoud, Righter, Anastasia
• Granted Patent: US 9,320,592 B2
• Time in Patent Office: Days
• US Class Current: 623/1.42
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2002/072 Encapsulated stents, e.g. wire or whole stent embedded in lining
• CPC Class Codes: A61F 2002/823 Stents, different from stent-grafts, adapted to cover an aneurysm
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: A61P 7/02 Antithrombotic agents; Anticoagulants; Platelet aggregation inhibitors
• CPC Class Codes: A61P 9/00 Drugs for disorders of the cardiovascular system

Abstract

Coating methods and related devices are provided. Such devices can include stents. For example, the device can comprise a sidewall and a plurality of pores in the sidewall that are sized to inhibit flow of blood through the sidewall into an aneurysm to a degree sufficient to lead to thrombosis and healing of the aneurysm when the tubular member is positioned in a blood vessel and adjacent to the aneurysm. The device can also comprise an anti-thrombogenic coating distributed over at least a portion of the device such that the pores are substantially free of webs formed by the coating.

Claims

1. A medical device for treating an aneurysm, comprising:

a tubular body configured to be implanted in a blood vessel and comprising a plurality of braided filaments, the body being expandable to an expanded state for treatment of the aneurysm, the body having a first section for spanning the neck of the aneurysm and a plurality of pores located between the filaments, the pores in the first section having a first average pore size of less than about 500 microns when the body is in the expanded state;

the first section having a substantially complete coating, comprising a coating material, over the filaments;

wherein the first section is substantially free of webs formed between the braided filaments by the coating material.

2. The medical device of claim 1, wherein the first average pore size is less than or equal to about 320 microns.

3. The medical device of claim 2, wherein the first average pore size is from about 50 microns to about 320 microns.

4. The medical device of claim 1, wherein the first average pore size is measured using an inscribed circle diameter.

5. The medical device of claim 1, wherein the first average pore size is the average size of the pores in the first section without the coating material.

6. The medical device as in claim 1, wherein the first section comprises less than an entire length of the tube.

7. The medical device as in claim 1, wherein the coating material on the first section is generally uniform over the filaments.

8. The medical device as in claim 1, wherein the coating comprises an antithrombogenic material.

9. The medical device as in claim 8, wherein the coating comprises an antithrombogenic polymer.

10. The medical device as in claim 8, wherein the coating comprises MPC.

11. The medical device as in claim 1, further comprising a second section having a plurality of pores having a second average pore size greater than the first average pore size.

12. The medical device as in claim 1, wherein the first section comprises a circumferential portion of the device that is at least 5 mm in length.

13. A delivery system for treating an aneurysm, the system comprising:

a microcatheter configured to be implanted into a blood vessel;

a core assembly, extending within the microcatheter, having a distal segment; and

the device of claim 1 extending along the core assembly distal segment.

14. The medical device as in claim 1, wherein the filaments comprise heat-treated metallic filaments.

15. The medical device as in claim 1, wherein the tubular body comprises a heat-set metallic braid.

16. The medical device as in claim 1, wherein the tubular body is self-expanding.

17. The medical device as in claim 1, wherein the device is less thrombogenic than an identical, uncoated device.

18. The medical device as in claim 17, wherein the device exhibits an elapsed time before peak thrombin formation that is at least 1.5 times the elapsed time of the identical, uncoated device.

19. The medical device as in claim 1, wherein the tubular body has an open proximal end, an open distal end, and forms a lumen extending from the proximal end to the distal end.

20. A method of coating a stent, the method comprising:

attaching first and second ends of the stent with upper and lower connectors of a holder device, the stent comprising a flow diverting section;

dipping the stent into a coating material to coat a first section of the stent; and

removing excess coating material from the stent such that the stent is free of webs formed by the coating material.

21. The method of claim 20, wherein the flow diverting section comprises a plurality of pores having an average pore size that is less than or equal to about 500 microns.

22. The method of claim 21, wherein the average pore size is less than or equal to about 320 microns.

23. The method of claim 22, wherein the average pore size is from about 50 microns to about 320 microns.

24. The method of claim 20, wherein dipping the stent into the coating material comprises dipping less than an entire length of the stent into the coating material to maintain an open air pocket adjacent to the stent first end.

25. The method of claim 20, wherein attaching the first and second ends of the stent comprises attaching the stent to the holder device such that the stent is held between the upper and lower connectors in a radially collapsed, longitudinally elongated state.

26. The method of claim 25, wherein the stent comprises a plurality of braided filaments, and wherein the stent filaments cross each other at substantially right angles when the stent is held in the elongated state.

27. The method of claim 26, wherein the elongated state is achieved when the stent filaments cross each other at angles in an angular range from about 80°

to about 110°

.

28. The method of claim 20, wherein the stent comprises a plurality of braided filaments, and the coating material on the stent is substantially free of webs such that the coating material does not bridge between adjacent filaments.

29. A method of coating a stent, the method comprising:

attaching a first end of the stent with an upper connector of a holder device, the stent comprising a plurality of braided filaments;

attaching a second end of the stent with a lower connector of the holder device such that the stent is held between the upper and lower connectors in a radially collapsed, longitudinally elongated state, the stent filaments crossing each other at substantially right angles when the stent is held in the elongated state;

while maintaining the stent in the elongated state, dipping the stent into a coating material to coat a first section of the stent; and

removing excess coating material from the stent.

30. The method of claim 29, wherein the elongated state is achieved when the stent filaments cross each other at angles in an angular range from about 80°

to about 110°

.

31. The method of claim 30, wherein the elongated state is achieved when the stent filaments cross each other at angles in an angular range from about 85°

to about 95°

.

32. The method of claim 29, wherein removing excess coating material comprises applying a stream of gas to the stent filaments, the stream of gas being of a sufficient strength to remove excess coating material from the stent.

33. The method of claim 29, wherein removing excess coating material comprises rotating the stent and holder device while applying a stream of gas to impinge upon an outer surface of the stent.

34. The method of claim 29, further comprising drying the coating material applied to the stent.

35. The method of claim 29, wherein dipping the stent into the coating material comprises dipping less than an entire length of the stent into the coating material to maintain an open air pocket adjacent to the stent first end.

36. The method of claim 29, wherein the holder device upper and lower connectors are interconnected such that the holder device is in a cantilevered configuration during the dipping and removing steps.

37. A method of coating a stent, the method comprising:

attaching a first end of the stent with an upper connector of a holder device, the stent comprising a plurality of braided filaments and a plurality of pores located between the filaments;

attaching a second end of the stent with a lower connector of the holder device such that the stent is held between the upper and lower connectors in a radially collapsed, longitudinally elongated state in which the filaments are oriented to substantially maximize an average inscribed area of the pores;

while maintaining the stent in the elongated state, dipping the stent into a coating material to coat a first section of the stent; and

removing excess coating material from the stent.

38. The method of claim 37, wherein the maximum average inscribed area of the pores is achieved when the filaments cross each other at substantially right angles.

39. The method of claim 38, wherein the maximum average inscribed area of the pores is achieved when the pores are substantially square.

40. The method of claim 38, wherein the maximum average inscribed area of the pores is achieved when the filaments cross each other at angles in an angular range from about 80°

to about 110°

.

41. The method of claim 38, wherein the maximum average inscribed area of the pores is achieved when the filaments cross each other at angles in an angular range from about 85°

to about 95°

.