Kinetic stent

• US 6,582,472 B2
• Filed: 02/26/1997
• Issued: 06/24/2003
• Est. Priority Date: 02/26/1997
• Status: Expired due to Fees

• Current Assignee: Applied Medical Resources Corporation (Applied Medical Corporation)
• Original Assignee: Applied Medical Resources Corporation (Applied Medical Corporation)
• Inventors: Hart, Charles C.
• Primary Examiner(s): Thaler, Michael H.
• Application Number:
  US08/806,337
• Publication Number:
  US 20020062148A1
• Time in Patent Office: 2,309 Days
• Field of Search: 606/198, 606/191, 606/195, 606/200, 623/1, 623/12, 623/1.2, 623/1.15, 623/23.7, 604/8
• US Class Current: 623/23.7
• 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 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2/848 having means for fixation to the vessel wall, e.g. barbs
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2230/0067 conical
• CPC Class Codes: A61M 27/008 pre-shaped, for use in the urethral or ureteral tract

Abstract

The disclosed stent is formed of an elongate, flexible duct having a very thin wall and a preformed diameter, length, and shape. The stent is constructed of a woven tubular structure of multiple strands or elements. The woven tubular structure is thermally set to a predetermined diameter and length, so that the “at rest” or natural condition of the tubular structure is predictable. A retention or holding member can be formed at one or both of the ends of the stent. This retention member can be reduced in diameter for insertion into the body passage. The woven tubular structure provides a path for fluids to flow in and around the stent, while a patent lumen is being developed. The woven tubular structure allows the stent to be extended or stretched over a guidewire or other noncompressive member, to thereby reduce the diameter of the stent for insertion of the stent into a body passage.

Claims

1. A ureteral stent adapted for disposition in a ureter between a bladder and a kidney of a patient to facilitate dilation of the ureter to a desired diameter, comprising:

a mesh body extending along an axis between a proximal end and a distal end, the body having a diameter and first properties for self-expanding to an ultimate diameter less than the desired diameter of the ureter so that the mesh body has a tendency to migrate within the ureter;

the mesh body having an initial diameter less than the ultimate diameter for facilitating insertion of the ureteral stent into the ureter;

the mesh body exhibiting the first properties for self-expansion between the initial diameter of the mesh body and the ultimate diameter of the mesh body;

the mesh body having second properties for maintaining a radial space between the stent and the ureter to inhibit tissue in-growth to the mesh body when the stent is operably disposed in the ureter;

a first anchor disposed at the distal end of the mesh body, the first anchor being configured for operative disposition in the kidney of the patient in order to inhibit migratation of the mesh body toward the bladder of the patient; and

a second anchor disposed at the proximal end of the mesh body, the second anchor being configured for operative disposition in the bladder of the patient in order to inhibit migration of the mesh body toward the kidney of the patient.

2. The ureteral stent recited in claim 1 wherein the second anchor has a bulbous configuration and is sized and configured for operative disposition in the bladder of a patient.

3. A ureteral stent adapted for disposition in the ureter of a patient between a bladder and a kidney of the patient to facilitate dilation of the ureter to a desired diameter, comprising:

a mesh body extending along an axis between a proximal end and a distal end the body having a diameter and first properties for self-expanding to an ultimate diameter less than the desired diameter of the ureter so that the mesh body has a tendency to migrate within the ureter;

a first anchor being disposed at the first end of the mesh body and being sized and configured for operative disposition in the kidney of the patient, the first anchor inhibiting the migration of the mesh body in a first direction;

a second anchor being disposed at the second end of the mesh body and being sized and configured for operative disposition in the bladder of the patient, the second anchor inhibiting the migration of the mesh body in a second direction opposite to the first direction;

the mesh body having an initial diameter less than the ultimate diameter for facilitating insertion of the ureteral stent into the ureter;

the mesh body exhibiting the first properties for self-expansion between the initial diameter and the ultimate diameter of the mesh body;

the mesh body having second properties for maintaining a radial space between the stent and the ureter to inhibit tissue in-growth to the mesh body when the stent is operably disposed in the ureter; and

at least one of the first anchor and the second anchor having a bulbous configuration of a cone with an apex and a base, the base being disposed between the mesh body and the apex of the cone.

6. The ureteral stent recited in claim 3, 4 or 5, wherein:

the mesh body has an initial diameter less than the ultimate diameter to facilitate insertion of the ureteral stent into the ureter.

7. The ureteral stent recited in claim 3, 4 or 5, wherein:

the mesh body has properties for maintaining a radial space between the stent and the ureter to inhibit tissue in growth to the mesh body when the stent is operatively disposed in the ureter.

4. A ureteral stent adapted for disposition in the ureter of a patient and adapted to extend completely from the bladder to the kidney of the patient to facilitate dilation of the ureter to a desired diameter, comprising:

a mesh body extending along an axis between a proximal end and a distal end, the body having a diameter and first properties for self-expanding to an ultimate diameter less than the desired diameter of the ureter so that the mesh body has a tendency to migrate within the ureter;

a first anchor having a bulbous configuration and being disposed at the first end of the mesh, the first anchor inhibiting the migration of the mesh body in a first direction, the first anchor sized and configured for operative disposition in the kidney of the patient; and

a second anchor being disposed at the second end of the mesh body, the second anchor inhibiting the migration of the mesh body in a second direction opposite to the first direction, the second anchor being sized and configured for operative disposition in the bladder of the patient.

5. A ureteral stent adapted for disposition in the ureter of a patient and configured to exten completely from the bladder to the kidney of the patient to facilitate dilation of the ureter to a desired diameter, comprising:

a mesh body extending along an axis between a proximal end and a distal end, the body having properties for self-expanding to a diameter not greater than an ultimate diameter less than the desired diameter of the ureter, so that the mesh body has a tendency to migrate within the ureter;

a first anchor having a bulbous configuration at the first end of the mesh, the first anchor being sized and configured for operative disposition in the kidney of the patient in order to inhibit migration of the mesh body toward the bladder; and

a second anchor disposed at the second end of the mesh body, and being sized and configured for operative disposition in the bladder of the patient in order to inhibit migration of the mesh body toward the kidney.

8. A ureteral stent adapted for disposition in the ureter of a patient, the ureter having an initial diameter and a desired ultimate diameter, the stent comprising:

a wall having the general configuration of a cylinder with a first end, a second end, and a diameter, the wall having properties providing the diameter of the cylinder with variable characteristics;

the wall having a first state wherein the diameter of the cylinder is less than about the initial diameter of the ureter in order to facilitate insertion of the stent into the ureter;

the wall having a second state wherein the cylinder has a maximum diameter sufficiently less than about the desired ultimate diameter of the ureter to facilitate creation of a space between the wall of the stent and the ureter in order to inhibit tissue ingrowth to the stent and to facilitate migration of the stent within the ureter;

a first anchor coupled to the first end of the wall and being adapted for disposition in the kidney to inhibit migration of the stent toward the bladder; and

a second anchor coupled to the second end of the wall and being adapted for disposition in the bladder to inhibit migration of the stent toward the kidney.

9. The ureter stent recited in claim 8, wherein the wall comprises:

a woven mesh providing the diameter of the wall with the variable characteristics.

10. The ureteral stent recited in claim 9, wherein:

the cylinder of the wall has an axis; and

the woven mesh in the first state of the wall is stretched axially to provide the cylinder with the diameter less than about the initial diameter of the ureter.

11. The ureteral stent recited in claim 9, wherein the woven mesh is formed of a thermoplastic material.

12. The ureteral stent recited in claim 11, wherein the thermoplastic material of the woven mesh is heatset to provide the cylinder with maximum diameter.

13. The ureteral stent recited in claim 8 wherein the wall has properties for self-expanding to automatically increase the diameter of the wall from the first state to the second state.

14. The ureteral stent recited in claim 8, wherein the space tends to facilitate migration of the stent within the ureter, and the stent further comprises:

at least one anchor coupled to the wall and being adapted for disposition in one of the kidneys and the bladder of the patient to inhibit the migration of the stent in the ureter.

15. A ureteral stent adapted for disposition in the ureter of a patient between a kidney and a bladder of the patient, in order to facilitate dilation of the ureter to a desired diameter, comprising:

a mesh body extending along an axis between a proximal end and a distal end, the body having a diameter and first properties for self-expanding to an ultimate diameter less than the desired diameter of the ureter so that the mesh body has a tendency to migrate within the ureter;

a first anchor having a bulbous configuration and being disposed at the distal end of the mesh body, the first anchor being adapted for operative disposition in the kidney of the patient in order to inhibit migration of the mesh body toward the bladder of the patient; and

a second anchor being disposed at the proximal end of the mesh body, the second anchor being adapted for operative disposition in the bladder of the patient in order to inhibit migration of the mesh body toward the kidney of the patient.

16. The ureteral stent recited in claim 15 further comprising

the mesh body having an initial diameter less than the ultimate diameter for facilitating insertion of the ureteral stent into the ureter; and

the mesh body exhibiting the properties for self-expansion between the initial diameter of the mesh body and the ultimate diameter of the mesh body.

17. The ureteral stent recited in claim 16, wherein:

the mesh body has second properties for maintaining a radial space between the stent and the ureter to inhibit tissue in-growth to the mesh body when the stent is operably disposed in the ureter.