Longitudinally expanding medical device

• US 20040193283A1
• Filed: 03/26/2003
• Published: 09/30/2004
• Est. Priority Date: 03/26/2003
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Rioux, Robert, Daignault, Ken
• Granted Patent: US 6,929,663 B2
• Time in Patent Office: Days
• US Class Current: 623/23.66
• 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 2002/047 Urethrae
• CPC Class Codes: A61M 2025/0024 Expandable catheters or sheaths
• CPC Class Codes: A61M 25/0012 with embedded structures, e.g. coils, braids, meshes, strands or radiopaque coils
• CPC Class Codes: A61M 25/0017 specially adapted for long-term hygiene care, e.g. urethral or indwelling catheters to prevent infections
• CPC Class Codes: A61M 25/005 with embedded materials for reinforcement, e.g. wires, coils, braids
• CPC Class Codes: A61M 25/0068 Static characteristics of the catheter tip, e.g. shape, atraumatic tip, curved tip or tip structure
• CPC Class Codes: A61M 25/0102 Insertion or introduction using an inner stiffening member, e.g. stylet or push-rod
• CPC Class Codes: A61M 25/04 in the body, e.g. expansible A61M25/10, A61M16/0488 take precedence

Abstract

A stent for maintaining an open passageway through a body lumen, such as the prostatic urethra of a male patient, includes an elongated segment including a flexible polymer material bridging a plurality of hoops. The elongated segment defines a lumen extending therethrough and has a distal end. A retention structure may be coupled to the distal end of the elongated segment to inhibit the distal end from migrating when the stent is placed within a body of a patient. The flexible polymer material is disposed between the plurality of hoops, thereby creating hinged members that allow for the spaces between the hoops to expand and contract longitudinally to accommodate prostatic swelling when the stent is placed within the prostatic urethra of the patient. A plurality of ridges is disposed along the elongated segment at locations where the flexible material circumscribes the hoops, and these inhibit migration of the stent and facilitate longitudinal expansion by frictionally engaging adjacent tissue, such as the inner wall of the prostatic urethra.

Claims

1. A medical device for use in a body of a patient, comprising:

an elongated segment comprising a plurality of hoops defining a lumen therethrough; and

a flexible polymer material bridging the plurality of hoops, the flexible polymer material allowing the elongated segment to expand and contract.

2. The medical device of claim 1 wherein each of the plurality of hoops comprises a wire.

3. The medical device of claim 2 wherein at least one of the wires comprises a biocompatible material, which comprises stainless steel, titanium, a nickel-titanium alloy, or a polymer.

4. The medical device of claim 1 wherein each of the hoops is spaced apart from at least one other of the hoops.

5. The medical device of claim 4 wherein the flexible polymer material is disposed between the plurality of hoops, allowing the spaces between the plurality of hoops to expand and contract to accommodate prostatic swelling when the device is within the prostatic urethra of the patient.

6. The medical device of claim 1 wherein the flexible polymer material comprises a low durometer silicone.

7. The medical device of claim 1 wherein the flexible polymer material is resilient.

8. The medical device of claim 1 further comprising a retention structure to inhibit migration of the device, the retention structure extending from a first end of the elongated segment.

9. The medical device of claim 8 wherein the retention structure comprises a coiled shape, a J-curl, a barb, or a malecot.

10. The medical device of claim 8 further comprising a second retention structure to inhibit migration of the device, the second retention structure extending from a second end of the elongated segment that is opposite the first end.

11. The medical device of claim 10 wherein the second retention structure comprises a coiled shape.

12. A stent for use in a prostatic urethra of a patient, comprising:

an elongated segment comprising a first end, a second end, and a plurality of hoops defining a lumen therethrough;

a flexible polymer material bridging the plurality of hoops to facilitate expansion of the elongated segment during prostatic swelling when the stent is within the prostatic urethra of the patient;

a first malecot comprising a proximal end and a distal end, the proximal end of the first malecot being disposed at the first end of the elongated segment; and

a curved tip disposed at the distal end of the first malecot.

13. The stent of claim 12 further comprising a second malecot disposed at the second end of the elongated segment.

14. The stent of claim 12 wherein each of the plurality of hoops comprises a wire.

15. The stent of claim 14 wherein at least one of the wires comprises a biocompatible material, which comprises stainless steel, titanium, a nickel-titanium alloy, or a polymer.

16. The stent of claim 12 wherein each of the hoops is spaced apart from at least one other of the hoops.

17. The stent of claim 12 wherein the flexible polymer material comprises a low durometer silicone.

18. The stent of claim 12 wherein the flexible polymer material is resilient.

19. A method of placing a stent in a prostatic urethra of a patient, the method comprising the steps:

(a) providing a stent comprising;

(i) an elongated segment comprising a plurality of hoops defining a lumen therethrough; and

(ii) a flexible polymer material bridging the plurality of hoops, the flexible polymer material allowing spaces between the plurality of hoops to expand and contract to accommodate swelling of a prostate when the stent is within the prostatic urethra of the patient; and

(b) inserting the stent into the prostatic urethra of the patient.

20. The method of claim 19 wherein the stent further comprises a retention structure to inhibit migration of the stent, the retention structure extending from a first end of the elongated segment.

21. The method of claim 19 wherein the inserting step comprises positioning the retention structure into a bladder of the patient.