Apparatus and method for removing stenotic material from stents

• US 5,902,263 A
• Filed: 12/24/1997
• Issued: 05/11/1999
• Est. Priority Date: 02/12/1997
• Status: Expired due to Fees

• Current Assignee: Prolifix Medical Incorporated
• Original Assignee: Prolifix Medical Incorporated
• Inventors: Leary, James J., Patterson, Greg R., Williams, G. Ronald
• Primary Examiner(s): Coggins, Wynn Wood
• Assistant Examiner(s): Blyveis, Deborah
• Application Number:
  US08/998,333
• Time in Patent Office: 503 Days
• Field of Search: 604/22, 604/264, 604/280, 600/658, 600/571, 600/572, 606/159, 606/170
• US Class Current: 604/22
• CPC Class Codes: A61B 17/221 Gripping devices in the form of loops or baskets for gripping calculi or similar types of obstructions surgical snare instruments A61B17/32056
• CPC Class Codes: A61B 17/3207 Atherectomy devices working by cutting or abrading; Similar devices specially adapted for non-vascular obstructions A61B17/32037 takes precedence; endoscopic cutting instruments A61B17/320016
• CPC Class Codes: A61B 17/320725 with radially expandable cutting or abrading elements A61B17/32075 takes precedence
• CPC Class Codes: A61B 17/320758 with a rotating cutting instrument, e.g. motor driven A61B17/320725, A61B17/32075 and A61B17/320783 take precedence; for removing intra-ocular material A61F9/00763; endoscopic rotatable cutting instruments A61B17/32002
• CPC Class Codes: A61B 2017/00026 Conductivity or impedance, e.g. of tissue
• CPC Class Codes: A61B 2017/00119 alarm; indicating an abnormal situation
• CPC Class Codes: A61B 2017/320012 Brushes
• CPC Class Codes: A61B 2090/378 using ultrasound
• CPC Class Codes: A61B 2217/005 with suction drainage system
• 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

Abstract

Apparatus and methods are provided for recanalizing stented regions within the vasculature which have become restenosed. A shearing body is displaced within the stented region in order to dislodge the stenotic material from an interface envelope defined by the inner surface of the stent. Usually, the shearing body will be compliant and sized slightly larger than the stent in order to remove stenotic material substantially uniformly around the entire interface envelope. The shearing body may be in the form of a brush, helical row, spaced-apart disks, solid compressible body, or a variety of other specific configurations.

Claims

1. A catheter system comprising:

an inner catheter shaft having a proximal end and a distal end;

a radially compressible compliant shearing body disposed near the distal end of the inner catheter shaft, wherein the shearing body has a first end and a second end and wherein the shearing body is tapered so that one end is larger than the other; and

a sheath having a proximal end, a distal end, and a cavity near the distal end, wherein the inner catheter is slidably coupled to the sheath so that the compliant shearing body can be radially constrained within and released from the cavity.

2. A catheter system as in claim 1, further comprising an outer catheter tube having a proximal end, a distal end, and a lumen therethrough, wherein the outer catheter tube comprises a hub at its proximal end, said hub having an aspiration port.

3. A catheter system as in claim 1, wherein the inner catheter shaft has a guidewire lumen extending from the proximal end to the distal end.

4. A catheter system as in claim 2, wherein the inner catheter shaft has a diameter in the range from 0.2 mm to 1 mm, the shearing body has a maximum width when radially unconstrained in the range of 2 mm to 5 mm, the sheath cavity has a diameter in the range from 0.75 mm to 2 mm, and the outer catheter tube has a lumen diameter in the range from 1.5 mm to 3 mm.

5. A catheter system as in claim 1, wherein at least a portion of the shearing body has a generally round cross-section.

6. A catheter system as in claim 1, wherein at least a portion of the shearing body has a polygonal cross-section.

7. A catheter system as in claim 1, wherein the shearing body comprises an axially elongate surface.

8. A catheter system as in claim 1, wherein the shearing body comprises a helical row.

9. A catheter system as in claim 8, wherein the helical row comprises a helically aligned radially oriented filaments.

10. A catheter system as in claim 8, wherein the helical row comprises a continuous web of material.

11. A catheter system as in claim 1, wherein the shearing body comprises a brush.

12. A catheter system as in claim 1, wherein the shearing body comprises a cage.

13. A catheter system as in claim 1, wherein the shearing body is compliant with an unconstrained width greater than the width of the sheath cavity so that the shearing body may be radially constrained within said cavity.

14. A catheter system as in claim 1, wherein the shearing body may be expanded by application of a compressive force in the axial direction, further comprising means for applying an axially compressive force to the shearing body.

15. A catheter system as in claim 1, further comprising a drive motor assembly which may be coupled to a proximal portion of the inner catheter shaft to rotate the inner catheter shaft.

16. A catheter system as in claim 15, wherein the drive motor assembly may also be attached to a proximal portion of the sheath, wherein the sheath is held stationary while the inner catheter shaft is rotated therein.

17. A catheter system as in claim 16, wherein the drive motor assembly permits the inner catheter shaft to be axially translated relative to the sheath so that the compliant shearing body can be released from and drawn into the cavity while the inner catheter shaft and sheath remain coupled to the drive motor assembly.

18. A catheter system comprising:

an inner catheter shaft having a proximal end and a distal end;

a radially compressible helical row of radially oriented filaments disposed near the distal end of the inner catheter shaft; and

a sheath having a proximal end, a distal end, and a cavity near the distal end, wherein the inner catheter is slidably coupled to the sheath so that the compliant shearing body can be radially constrained within and released from the cavity.

19. A catheter system as in claim 18, further comprising an outer catheter tube having a proximal end, a distal end, and a lumen therethrough, wherein the outer catheter tube comprises a hub at its proximal end, said hub having an aspiration port.

20. A catheter system as in claim 18, wherein the inner catheter shaft has a guidewire lumen extending from the proximal end to the distal end.

21. A catheter system as in claim 20, wherein the inner catheter shaft has a diameter in the range from 0.2 mm to 1 mm, the helical row has a maximum width when radially unconstrained in the range of 2 mm to 5 mm, the sheath cavity has a diameter in the range from 0.75 mm to 2 mm, and the outer catheter tube has a lumen diameter in the range from 1.5 mm to 3 mm.

22. A catheter system as in claim 18, wherein at least a portion of the helical row has a generally round cross-section.

23. A catheter system as in claim 18, wherein at least a portion of the helical row has a polygonal cross-section.

24. A catheter system as in claim 18, wherein the helical row is tapered at at least one end, with said one end having a smaller width than other portions of the helical row.

25. A catheter system as in claim 18, wherein the helical row is compliant with an unconstrained width greater than the width of the sheath cavity so that the shearing body may be radially constrained within said cavity.

26. A catheter system as in claim 18, further comprising a drive motor assembly which may be coupled to a proximal portion of the inner catheter shaft to rotate the inner catheter shaft.

27. A catheter system as in claim 26, wherein the drive motor assembly may also be attached to a proximal portion of the sheath, wherein the sheath is held stationary while the inner catheter shaft is rotated therein.

28. A catheter system as in claim 27, wherein the drive motor assembly permits the inner catheter shaft to be axially translated relative to the sheath so that the compliant shearing body can be released from and drawn into the cavity while the inner catheter shaft and sheath remain coupled to the drive motor assembly.