Removable stent and method of using the same

• US 7,547,321 B2
• Filed: 07/05/2002
• Issued: 06/16/2009
• Est. Priority Date: 07/26/2001
• Status: Expired due to Term

• Current Assignee: Merit Medical Systems, Inc.
• Original Assignee: Alveolus, Inc. (Merit Medical Systems, Inc.)
• Inventors: Silvestri, Gerard A., Freitag, Lutz
• Primary Examiner(s): Stewart; Alvin J
• Application Number:
  US10/190,770
• Publication Number:
  US 20030024534A1
• Time in Patent Office: 2,538 Days
• Field of Search: 623/23.7, 623/1.15
• US Class Current: 623/1.15
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/041 Bile ducts
• CPC Class Codes: A61F 2002/044 Oesophagi or esophagi or gullets
• CPC Class Codes: A61F 2002/046 Tracheae
• CPC Class Codes: A61F 2002/065 Y-shaped blood vessels
• CPC Class Codes: A61F 2002/91516 the meander having a change in frequency along the band
• CPC Class Codes: A61F 2002/91525 within the whole structure different bands showing different meander characteristics, e.g. frequency or amplitude
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2002/91566 connected trough to trough
• CPC Class Codes: A61F 2230/0054 V-shaped
• CPC Class Codes: A61F 2250/0018 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0039 differing in diameter
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: A61L 31/022 Metals or alloys
• CPC Class Codes: A61P 35/00 Antineoplastic agents

Abstract

The present invention, in an exemplary embodiment, provides a stent, which combines many of the excellent characteristics of both silicone and metal stents while eliminating the undesirable ones. In particular, it is an objective of a preferred embodiment of the present invention to provide a stent that is easily installed, yet removable. Moreover, the stent does not cause material infections and has the capacity to reduce infection. Therefore, a principal objective of a preferred embodiment in accordance with the present invention is to provide a prosthesis that is suitable for both permanent and temporary use while being easy to insert, reposition and remove. This prosthesis is also suitable for targeted delivery of antimicrobial and chemotherapeutic agents. Additionally, a principal objective in accordance with the present invention is to provide a family of stents where the relative hardness/softness of regions of the stent can differ from other regions of the stent to provide additional patient comfort and resistance to radial forces. An exemplary embodiment also provides a family of stents with novel interstice configurations that facilitate flexibility, durability and/or proper installation.

Claims

1. A medical appliance for placement within and removal from a portion of the anatomy of a patient, the appliance comprising:

a scaffolding, the scaffolding configured to define a substantially cylindrical member having a distal end and a proximal end and extending longitudinally there between, forming a lumen there through, such that when pressure is exerted along varying points of the longitudinal extension of the appliance, the appliance does not undesirably foreshorten or elongate, said scaffolding comprising;

a plurality of expandable circumferential bands formed of struts having interconnected ends defining a series of alternating peaks and valleys, said peaks and valleys of adjacent circumferential bands being in-phase except for at least one out-of-phase pair of circumferential bands, and

a plurality of flexible connectors extending between each pair of the circumferential bands, wherein at least one set of the flexible connectors extends between and connects at least one pair of peaks or one pair of valleys of the out-of-phase pair of circumferential bands, wherein,

each of the plurality of connectors are spaced apart from one another by at least one pair of peaks and one pair of valleys of adjacent circumferential bands, and further wherein

the distal end of the cylindrical member is defined by a circumferential band connected to flexible connectors that extend only in the proximal direction, and the proximal end of the cylindrical member is defined by a circumferential band connected to flexible connectors that extend only in the distal direction.

2. The medical appliance of claim 1, wherein the medical appliance comprises at least three circumferential bands and a plurality of flexible connectors extending therebetween, and wherein a pair of the flexible connectors extending between adjacent circumferential rows are in axial alignment with one another.

3. A medical appliance for placement within and removal from a portion of the anatomy of a patient, the appliance comprising:

a scaffolding, the scaffolding configured to define a substantially cylindrical member having a distal end and a proximal end and extending longitudinally there between, forming a lumen there through, such that when pressure is exerted along varying points of the longitudinal extension of the appliance, the appliance does not undesirably foreshorten or elongate, wherein along the longitudinal extension of the appliance, the scaffolding forms geometrical patterns, said scaffolding comprising;

a plurality of expandable circumferential bands formed of struts having interconnected ends defining a series of alternating peaks and valleys, said peaks and valleys of adjacent circumferential bands being in-phase except for at least one out-of-phase pair of circumferential bands, and

a plurality of flexible connectors extending between each pair of the circumferential bands, wherein at least one set of the flexible connectors extends between and connects at least one pair of peaks or one pair of valleys of the out-of-phase pair of circumferential bands,

each of the flexible connectors including a substantially U-shaped connector member coupled with portions of the geometrical patterns, the U-shaped connector comprising a crossing member and a plurality of leg members extending from the crossing member, wherein the length of the leg members and the degree of the angle at which the legs extend from the crossing member determines the relative flexibility of the medical appliance, wherein,

each of the plurality of connectors are spaced apart from one another by at least one pair of peaks and one pair of valleys of adjacent circumferential bands, and further wherein

the distal end of the cylindrical member is defined by a circumferential band connected to flexible connectors that extend only in the proximal direction, and the proximal end of the cylindrical member is defined by a circumferential band connected to flexible connectors that extend only in the distal direction.

4. The medical appliance of claim 3, wherein the angle at which the leg members extend from the crossing member is greater than about 90°

.

5. The medical appliance of claim 4, wherein the medical appliance is relatively rigid.

6. The medical appliance of claim 3, wherein the angle at which the leg members extend from the crossing member is about 90°

or less.

7. The medical appliance of claim 6, wherein the medical appliance is relatively flexible.

8. A medical appliance for placement within and removal from a portion of the anatomy of a patient, the appliance comprising:

a scaffolding, the scaffolding configured to define a substantially cylindrical member having a distal end and a proximal end and extending longitudinally there between, forming a lumen there through, such that when pressure is exerted along varying points of the longitudinal extension of the appliance, the appliance does not undesirably foreshorten or elongate, wherein the thickness of the scaffolding is about between 150 μ

m and 220 μ

m said scaffolding comprising;

a plurality of expandable circumferential bands formed of struts having interconnected ends defining a series of alternating peaks and valleys, said peaks and valleys of adjacent circumferential bands being in-phase except for at least one out-of-phase pair of circumferential bands, and

a plurality of flexible connectors extending between each pair of the circumferential bands, wherein at least one set of the flexible connectors extends between and connects at least one pair of peaks or one pair of valleys of the out-of-phase pair of circumferential bands, wherein,

each of the plurality of connectors are spaced apart from one another by at least one pair of peaks and one pair of valleys of adjacent circumferential bands, and further wherein

the distal end of the cylindrical member is defined by a circumferential band connected to flexible connectors that extend only in the proximal direction, and the proximal end of the cylindrical member is defined by a circumferential band connected to flexible connectors that extend only in the distal direction.

9. The medical appliance in accordance with claim 8, wherein the scaffolding thickness is about between 175 μ

m and 210 μ

m.

10. The medical appliance of claim 9, wherein the thickness of the scaffolding is about between 195 μ

m and 205 μ

m.

11. The medical appliance of claim 10, wherein the scaffolding thickness is about 205 μ

m.

12. A method of treating a patient suffering from luminal irregularities, comprising the steps of:

providing a medical appliance comprising a scaffolding, the scaffolding configured to define a substantially cylindrical member having a distal end and a proximal end and extending longitudinally there between, forming a lumen there through, such that when pressure is exerted along varying points of the longitudinal extension of the appliance, the appliance does not undesirably foreshorten or elongate, said scaffolding comprising;

a plurality of expandable circumferential bands formed of struts having interconnected ends defining a series of alternating peaks and valleys, said peaks and valleys of adjacent circumferential bands being in-phase except for at least one out-of-phase pair of circumferential bands, and

a plurality of flexible connectors extending between each pair of the circumferential bands, wherein at least one set of the flexible connectors extends between and connects at least one pair of peaks or one pair of valleys of the out-of-phase pair of circumferential bands, wherein each of the plurality of connectors are spaced apart from one another by at least one pair of peaks and one pair of valleys of adjacent circumferential bands, and further wherein the distal end of the cylindrical member is defined by a circumferential band connected to flexible connectors that extend only in the proximal direction, and the proximal end of the cylindrical member is defined by a circumferential band connected to flexible connectors that extend only in the distal direction;

installing the medical appliance in a non-vascular lumen of the patient;

activating the expansion of the medical appliance in the desired location; and

removing the medical appliance from the lumen of the patient.

13. A medical appliance for placement within and removal from a portion of the anatomy of a patient, the appliance comprising:

an electropolished scaffolding, the scaffolding configured to define a substantially cylindrical member having a distal end and a proximal end and extending longitudinally there between, forming a lumen there through, such that when pressure is exerted along varying points of the longitudinal extension of the appliance, the appliance does not undesirably foreshorten or elongate, said scaffolding comprising;

a plurality of expandable circumferential bands formed of struts having interconnected ends defining a series of alternating peaks and valleys, said peaks and valleys of adjacent circumferential bands being in-phase except for at least one out-of-phase pair of circumferential bands, and

a plurality of flexible connectors extending between each pair of the circumferential bands, wherein at least one set of the flexible connectors extends between and connects at least one pair of peaks or one pair of valleys of the out-of-phase pair of circumferential bands, wherein,

each of the plurality of connectors are spaced apart from one another by at least one pair of peaks and one pair of valleys of adjacent circumferential bands, and further wherein

the distal end of the cylindrical member is defined by a circumferential band connected to flexible connectors that extend only in the proximal direction, and the proximal end of the cylindrical member is defined by a circumferential band connected to flexible connectors that extend only in the distal direction and,

wherein the scaffolding is electropolished.

14. The medical appliance of claim 13, wherein along the longitudinal extension of the appliance, the scaffolding forms geometrical patterns.

15. The medical appliance of claim 14, wherein the dimensions of the scaffolding geometry determine torsionality of the medical appliance.

16. The medical appliance of claim 14, further comprising a substantially U-shaped connector member coupled with portions of the geometrical patterns, the U-shaped connector comprising a crossing member and a plurality of leg members extending from the crossing member.

17. The medical appliance of claim 16, wherein the substantially U-shaped connector further comprises a rectangular detent extending from a leg thereof.

18. The medical appliance of claim 16, wherein the length of the leg members and the degree of the angle at which the legs extend from the crossing member determines the relative flexibility of the medical appliance.

19. The medical appliance of claim 18, wherein the angle at which the leg members extend from the crossing member is greater than about 90°

.

20. The medical appliance of claim 19, wherein the medical appliance is relatively rigid.

21. The medical appliance of claim 18, wherein the angle at which the leg members extend from the crossing member is about 90°

or less.

22. The medical appliance of claim 21, wherein the medical appliance is relatively flexible.

23. The medical appliance of claim 14, wherein the geometrical patterns are substantially W-shaped.

24. The medical appliance of claim 14, wherein the geometrical patterns are substantially V-shaped.

25. The medical appliance of claim 14, wherein the geometrical patterns are substantially Z-shaped.

26. The medical appliance of claim 14, wherein the geometrical patterns are substantially S-shaped.

27. The medical appliance of claim 14, wherein the geometrical patterns are substantially X-shaped.

28. The medical appliance of claim 13, wherein the scaffolding is formed of a memory capable alloy.

29. The medical appliance of claim 28, wherein the memory capable alloy has antimicrobial properties.

30. The medical appliance of claim 29, wherein the antimicrobial alloy is selected from the group consisting of group eleven metals.

31. The medical appliance of claim 13, wherein near the distal and proximal ends of the scaffolding the medical appliance further comprise a plurality of flanges that define apertures there through.

32. The medical appliance of claim 13, wherein the scaffolding further comprises an antimicrobial agent coupled therewith.

33. The medical appliance of claim 32, wherein the antimicrobial agent is selected from the group consisting of tetracyclines, rifamycins, macrolides, penicillins, cephalosporins, p-lactam antibiotics, aminoglycosides, chloramphenicols, sulfonamides, glycopeptides, quinolones, fluidic acid, trimethoprim, metornidazole, clindamycin, mupirocin, polyenes, azoles, and beta-lactam inhibitors.

34. The medical appliance of claim 13, wherein the scaffolding further comprises an antiseptic or disinfectant coupled therewith.

35. The medical appliance of claim 34, wherein the antiseptic or disinfectant is selected from the group consisting of thymol, .alpha.-terpineol, methylisothiazolone, cetylpyridinium, chloroxylenol, hexachlorophene, cationic biguanides, methylene chloride, iodine and iodophores, triclosan, furan medical preparations, methenamine, aldehydes and alcohols.

36. The medical appliance of claim 13, wherein the scaffolding may be made in its entirety or in part of an antimicrobial metal.

37. The medical appliance of claim 13, wherein at least one surface of the scaffolding may have embedded, by ion beam assisted deposition, therein with atoms of an antimicrobial metal.

38. The medical appliance of claim 13, wherein the scaffolding further comprises a chemotherapeutic agent coupled therewith.

39. The medical appliance of claim 38, wherein the chemotherapeutic agent is selected from the group consisting of DNA-interactive Agents, Antimetabolites, Tubulin-Interactive Agents, Hormonal agents and others such as Asparaginase or Hydroxyurea.

40. The medical appliance of claim 39, wherein the DNA-Interactive Agents are selected from the group consisting of alkylating agents, the DNA strand-breakage agents, the intercalating topoisomerase II inhibitors, and the nonintercalating topoisomerase H inhibitors.

41. The medical appliance of claim 40, wherein the alkylating agents are selected from the group consisting of Nitrogen mustards, aziridines, nitroso ureas, platinum complexes, bioreductive alkylator, DNA strand breaking agents, Intercalators and nonintercalators.

42. The medical appliance of claim 39, wherein the Antimetabolites are selected from the group consisting of folate antagonists such as Methotrexate and trimetrexate;

pyrimidine antagonists, such as Fluorouracil, Fluorodeoxyuridine, CB3717, Azacytidine, Cytarabine;

Floxuridine purine antagonists include Mercaptopurine, 6-Thioguanine, Fludarabine, Pentostatin;

sugar modified analogs include Cyctrabine, Fludarabine; and

ribonucleotide reductase inhibitors include Hydroxyurea.

43. The medical appliance of claim 13, wherein the scaffolding further comprises a hormonal agent coupled therewith.

44. The medical appliance of claim 43, wherein the hormonal agent is selected from the group consisting of estrogens, conjugated estrogens;

progestins; and

androgens.

45. The medical appliance of claim 13, wherein the scaffolding further comprises an anti-hormonal agent coupled therewith.

46. The medical appliance of claim 45, wherein the anti-hormonal agent is selected from the group consisting of antiestrogenic, antiandrogen agents, and antiadrenal agents.

47. The medical appliance of claim 46, wherein the thickness of the scaffolding is about between 150 μ

m and 220 μ

m.

48. The medical appliance in accordance with claim 47, wherein the scaffolding thickness is about between 175 μ

m and 210 μ

m.

49. The medical appliance of claim 48, wherein the thickness of the scaffolding is about between 195 μ

m and 205 μ

m.

50. The medical appliance of claim 49, wherein the scaffolding thickness is about 205 μ

m.

51. A method of treating a patient suffering from luminal irregularities, comprising the steps of:

providing a medical appliance comprising an electropolished scaffolding, the scaffolding configured to define a substantially cylindrical member having a distal end and a proximal end and extending longitudinally there between, forming a lumen there through, such that when pressure is exerted along varying points of the longitudinal extension of the appliance, the appliance does not undesirably foreshorten or elongate, said scaffolding comprising;

a plurality of expandable circumferential bands formed of struts having interconnected ends defining a series of alternating peaks and valleys, said peaks and valleys of adjacent circumferential bands being in-phase except for at least one out-of-phase pair of circumferential bands, and

a plurality of flexible connectors extending between each pair of the circumferential bands, wherein at least one set of the flexible connectors extends between and connects at least one pair of peaks or one pair of valleys of the out-of-phase pair of circumferential bands, wherein each of the plurality of connectors are spaced apart from one another by at least one pair of peaks and one pair of valleys of adjacent circumferential bands, and further wherein the distal end of the cylindrical member is defined by a circumferential band connected to flexible connectors that extend only in the proximal direction, and the proximal end of the cylindrical member is defined by a circumferential band connected to flexible connectors that extend only in the distal direction;

installing the medical appliance in a preferred location of the anatomy of the patient; and

activating the expansion of the medical appliance in the desired location.

52. The method of claim 51, wherein the preferred location is a non-vascular lumen.

53. The method of claim 52, further comprising the step of removing the medical appliance from the anatomy of the patient.

54. The method of claim 52, wherein the medical appliance further comprises anti-microbial agents coupled therewith.

55. The method of claim 52, wherein the medical appliance further comprises chemotherapeutic agents coupled therewith.