Stent for Use in a Tubular Organ of a Body

• US 20090177288A1
• Filed: 10/29/2005
• Published: 07/09/2009
• Est. Priority Date: 10/29/2005
• Status: Abandoned Application

• Current Assignee: Pnn Medical SA
• Original Assignee: Pnn Medical SA
• Inventors: Wallsten, Hans I.
• Application Number:
  US12/084,210
• Publication Number:
  US 20090177288A1
• Time in Patent Office: Days
• US Class Current: 623/23.660
• CPC Class Codes: A61F 2/04 Hollow or tubular parts of organs, e.g. bladders, tracheae, bronchi or bile ducts A61F2/18, A61F2/20 take precedence; devices, other than stent-grafts, providing patency to, or preventing collapsing of, tubular structures of the body other than stent-grafts, e.g. stents A61F2/82; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95
• CPC Class Codes: A61F 2/88 the wire-like elements formed as helical or spiral coils forming a net-like or mesh-like structure A61F2/90
• CPC Class Codes: A61F 2/885 comprising a coil including a plurality of spiral or helical sections with alternate directions around a central axis
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2002/047 Urethrae
• CPC Class Codes: A61F 2002/9505 having retaining means other than an outer sleeve, e.g. male-female connector between stent and instrument
• CPC Class Codes: A61F 2210/0042 using a fluid, e.g. circulating
• CPC Class Codes: A61F 2230/008 paraboloidal
• CPC Class Codes: A61M 27/008 pre-shaped, for use in the urethral or ureteral tract

Abstract

The present invention relates to a stent (1′) for use in a tubular organ of a body. The stent (1′) comprises a first part (8) to be positioned in a diseased part (2) of the organ and acting as a stentbody therein, and a second part (10, 10′, 40) to be positioned in a non-diseased part (6) of the organ and acting as an anchoring element therein. The two parts (8; 10, 10′, 40) are being designed as tubular members interconnected at the ends facing one another by a flexible, axially rigid connecting part (9), at least said second part (10, 10′, 40) having memorized therein a capacity to expand radially after an increase in temperature, thereby providing anchorage of the second part (10, 10′, 40) at a determined distance away from the diseased part (2) of the organ. The present invention further relates to a catheter (12, 50) and a method for using the stent (1′) and catheter (12, 50).

Claims

1. A stent (1′

) for use in a tubular organ of a body, comprising a first part (8) to be positioned in a diseased part (2) of the organ and acting as a stentbody therein, and a second part (10, 10′

, 40) to be positioned in a non-diseased part (6) of the organ and acting as an anchoring element therein, said two parts (8;

10, 10′

, 40) being designed as tubular members interconnected at the ends facing one another by a flexible, axially rigid connecting part (9), at least said second part (10, 10′

, 40) having memorised therein a capacity to expand radially after an increase in temperature, thereby providing anchorage of the first part (8) at a determined distance away from the diseased part (2) of the organ.

2. A stent (1′

) according to claim 1, for use in the urethra (2), wherein said first part (8) is adapted to be positioned in the prostatic urethra (2), and said second part (10, 10′

, 40) is adapted to be positioned in the bulbar urethra (6) on the opposite side of a sphincter (5), wherein said connecting part (9) has a length equal to or larger than the axial extension of the sphincter (5).

3. A stent (1′

) according to any one of the preceding claims, wherein at least said second part (10, 10′

, 40) is in its non-expanded state designed as a wound tubular spiral.

4. A stent (1′

) according to claim 3, wherein, in the expanded state of said stent (1′

), said second part (10, 10′

, 40) at least at one portion along its axial length, has a diameter that is larger than the diameter of the first part (8).

5. A stent (1′

) according to claim 4, wherein, in the expanded state of said stent (1′

), the second part (10, 10′

, 40) at least at one portion along its axial length has a diameter that is at least 1.5 times the diameter of the first part (8).

6. A stent (1′

) according to any one of the preceding claims, wherein said second part (10, 10′

, 40) has a proximal end section and a distal end section, wherein said capacity to expand radially is memorised into at least one of said end sections.

7. A stent (1′

) according to claim 6, wherein each axial expansion of said end sections forms a flaring flange.

8. A stent (1′

) according to claim 7, wherein each flaring flange is facing away from the second part (10, 10′

, 40).

9. A stent (1′

) according to any one of the preceding claims, wherein said capacity to expand extends axially all along the stent (1′

).

10. A stent (1′

) according to any one of the preceding claims, wherein a distal end of said second part (10, 10′

, 40) is adapted to expand radially at expansion so as to be released from a catheter (12, 50) onto which the stent (1′

) is arranged at implantation thereof into a patient.

11. A stent (1′

) according to any one of the preceding claims, wherein at least said second part (10, 10′

, 40) is made of a memory or a recovery metal.

12. A stent (1′

) according to any one of the preceding claims, wherein at least a proximal end of said second part (10′

, 40) is designed so as not to rotate during expansion thereof.

13. A stent (1′

) according to claim 12, wherein a thread (42) is attached to the proximal end of said stent (1′

).

14. A stent (1′

) according to claim 12 or 13, wherein said second part (10′

, 40) is divided into an even number of pairwise arranged sections wound in opposite directions, the change in direction between adjoining two sections being obtained by a turn or fold (41), said sections being of substantially equal length.

15. A stent (1′

) according to any one of the preceding claims, wherein its three parts are integrally formed.

16. A stent (1′

) according to any one of the preceding claims, wherein, after expansion thereof, said connecting part (9) is arranged approximately at a centre line along the axial direction of said stent (1′

).

24. A catheter (12, 50) according to any one of the claims 17-23, wherein said catheter (12, 50) is adapted for implantation of a stent (1′

) according to any one of the claims 1-16.

25. A method for the implantation of a stent (1′

) in a urethra (2, 6) using a catheter (12, 50) comprising a catheter shaft (20, 51, 52;

61) onto which a stent (1′

) according to any one of the claims 1 to 16 is arranged, said method comprising the steps of;

inserting the catheter (12, 50) carrying said stent (1′

) into said urethra (2, 6);

positioning the catheter (12, 50) so as to place a stentbody (8) of said stent (1′

) within the urethra (2, 6) with an end thereof in close proximity of a sphincter (5);

releasing the capacity to expand radially of at least an anchoring element (10, 10′

, 40) of said stent (1′

);

allowing at least said anchoring element (10, 10′

, 40) to expand so as to provide anchorage of said stent (1′

) in said position; and

releasing said stent (1′

) from the catheter shaft (20, 51, 52;

61) and withdrawing same from the urethra (2, 6) leaving said stent (1′

) in position.

26. A method according to claim 25, wherein the capacity to expand is released by an increase in temperature caused by a warm liquid.

27. A method according to claim 25, wherein the capacity to expand is released by an increase in temperature caused by the body into which the catheter and stent (1′

) is implanted.

28. A method according to any one of the claims 25-27, wherein the release of the stent (1′

) from the catheter shaft is caused by the radial expansion of said anchoring element (10, 10′

, 40).

29. A method according to claim 25-28, wherein said catheter (12) comprises in its distal end a balloon (13), wherein during positioning of the catheter (12) with said stent (1′

) within said urethra (2, 6) the distal end of the catheter (12) is inserted into the bladder, said balloon (13) is inflated within the bladder, and the catheter (12) is retracted until the balloon (13) is lying against the bladder neck (4), thereby defining the position of said stent (1′

).

30. A method according to claim 25-28, wherein said catheter (12, 50) is provided with at least one inspection opening (55) enabling direct vision with an endoscope (57), wherein during positioning of the catheter (12, 50) with said stent (1′

) within said urethra (2, 6) the inspection opening (55) with the endoscope (57) is inserted into said urethra (2, 6); and

finding via direct vision in the endoscope (57) the distal end of the sphincter (5), thereby defining the position of a proximal part of the stentbody (8).

31. A method according to any one of the claims 25-30, wherein said stent (1′

) is made at least partly of a material having memory capacity, wherein said method further comprises the step of;

introducing a liquid at a temperature below a material softening point at the parts of the stent (1′

) to be softened, thereby softening at least parts of the stent (1′

) material.

32. A method according to claim 31, wherein the liquid is introduced only into the bulbar urethra (6).

33. A method according to any one of the claims 25-32, wherein the method further comprises the step of:

grasping a proximal end of said stent (1′

) and withdrawing said stent (1′

) from the urethra (2, 6).

34. A method according to any one of the claims 25-32, wherein the method further comprises the step of:

grasping a thread (42) which is attached to the proximal end of said stent (1′

) and withdrawing said stent (1′

) from said urethra (2, 6).

17. A catheter (12, 50) for the implantation in a tubular organ of the body of a stent (1′

) having a first part acting as a stentbody (8), a second part acting as an anchoring element (10, 10′

, 40) and there between a connecting part (9), said catheter (12, 50) comprising a catheter shaft (20, 61, 51) with a handle (21) and stent expansion means at its proximal end and a stent holding part (70) at its distal end, wherein said stent holding part (70) is divided into a distal stentbody holding part, a proximal anchoring element holding part and there between holding means (11, 53) for releasable holding of said connecting part (9) of the stent (1′

) when said stent (1′

) is arranged on said catheter (12, 50).

18. A catheter (12, 50) according to claim 17, wherein said holding means (11, 53) is constituted by a sleeve enclosing said catheter shaft (20, 51, 52;

61) and provided with an axially extending slit (26) along its length, said slit (26) accommodating said connecting part (9) when a stent (1) is arranged on said catheter (12, 50).

19. A catheter (12) according to any one of the claims 17-18, wherein said stent expansion means comprise connecting means (22) at the proximal end of the catheter shaft (20) for the introduction of a warm liquid into channels (32) within the wall of said catheter shaft (20), which channels (32) are interconnected with outlet openings (24) at the stent holding part (70) for said warm liquid, wherein said outlet openings (24) are provided at least at the anchoring element holding part.

20. A catheter (12) according to any one of the claims 17-19, further comprising a positioning balloon (13) attached at the distal end of said catheter shaft (20) and connected via the catheter shaft (20) to a source of a pressure medium for the purpose of expanding the balloon (13) when positioned in the urinary bladder during implantation.

21. A catheter (50) according to any one of the claims 17-18, wherein said stent expansion means comprise a cylinder (60) having wire locking means in its distal end and an operating element (62) at its proximal end, said cylinder (60) and operating element (62) being rotationally and concentrically arranged around said catheter (50) at said handle (21), wherein said cylinder (60), when a stent (1′

) is arranged on said catheter (50), is adapted to control the expansion of the stent (1′

).

22. A catheter (12, 50) according to any one of the claims 17-18 or 21, wherein said holding means (11, 53) is provided with at least one inspection opening (55) through which the position of the proximal end of the stentbody (8) in relation to the sphincter (5) can be accurately determined by an endoscope (57) introduced through a passage in the catheter shaft (20, 51, 52;

61) in use of said catheter (12, 50).

23. A catheter (12, 50) according to claim 22, wherein said inspection opening (55) extends somewhat into the proximal end of the part of the catheter shaft (20, 51, 52;

61) embraced by the stentbody (8) when a stent (1′

) is arranged on said catheter (12, 50).