Methods and apparatus for flow restoration

• US 8,940,003 B2
• Filed: 02/20/2009
• Issued: 01/27/2015
• Est. Priority Date: 02/22/2008
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Slee, Earl Howard, Wilder, Thomas III, McCarthy, Thomas, Franco, David, Ashby, Mark Philip, Shrivastava, Sanjay
• Primary Examiner(s): MCEVOY, THOMAS M
• Application Number:
  US12/918,795
• Publication Number:
  US 20110060212A1
• Time in Patent Office: 2,167 Days
• Field of Search: 606/127, 606/128, 606/159, 606/191, 606/194, 606/200
• US Class Current: 606/159
• CPC Class Codes: A61B 17/22 Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for dilators A61M29/00
• 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 2017/22034 for gripping the obstruction or the tissue part from inside
• CPC Class Codes: A61B 2017/22094 for crossing total occlusions, i.e. piercing
• CPC Class Codes: A61B 2017/2215 having an open distal end
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• 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 2/92 Stents in the form of a rolled-up sheet expanding after insertion into the vessel , e.g. with a spiral shape in cross-section

Abstract

Methods for restoring blood flow in occluded blood vessels using an apparatus having a self expandable distal segment that is pre-formed to assume a superimposed structure in an unconstrained condition but can be made to take on a volume-reduced form making it possible to introduce it with a microcatheter and a push wire arranged at the proximal end, with the distal segment in its superimposed structure assuming the form of a longitudinally open tube and having a mesh structure of interconnected strings or filaments or struts. In a preferred embodiment, the distal segment has a tapering structure at its proximal end where the strings or filaments or struts converge at a connection point.

Claims

1. A self-expandable apparatus for removal of a thrombus in a blood vessel, comprising:

a tubular structure having a proximal end and a distal end, the structure having (a) a distal portion comprising a first plurality of cells, (b) a proximal portion comprising a second plurality of cells,(c) a first diameter at the distal end, and (d) a second diameter at the proximal end, the distal portion having a distally widening taper at a distal end portion of the distal portion such that the first diameter is greater than the second diameter, the apparatus further comprising a connection point located at a proximal end of the proximal portion wherein the proximal portion converges at the connection point, the apparatus further comprising two edges extending parallel to a longitudinal axis of the structure, wherein the structure is configured to assume an expanded configuration at the place of implantation, and wherein the structure is configured to be modified into a volume-reduced configuration for insertion within a microcatheter, the volume-reduced configuration having a smaller cross-sectional dimension than the expanded configuration, the two edges being overlapped in the volume-reduced configuration, wherein the structure is configured to expand into the thrombus when transitioning from the volume-reduced configuration to the expanded configuration.

2. The apparatus of claim 1, wherein the distal end of the structure comprises radiopaque markers having a spiral or eyelet shape.

3. The apparatus of claim 1, wherein the distal end of the structure is bent and extends distally at an acute angle relative to the longitudinal axis of the structure.

4. The apparatus of claim 1, the structure comprising a first plurality of cells at a proximal portion, a second plurality of cells at a tapered portion, and wherein the distal end of the structure comprises a third plurality of cells and wherein said third plurality of cells has a smaller cell size than the second plurality of cells.

5. The apparatus of claim 1, wherein the distal end of the structure comprises one or more pegs and/or hooks.

6. The apparatus of claim 1, wherein the distal end of the structure further comprises the addition of synthetic fibers.

7. The apparatus of claim 1, wherein the distal end of the structure has been heated for a sufficient time to provide increased radial strength.

8. The apparatus of claim 1, wherein the structure is coated with an anticoagulant or antiplatelet drug.

9. The apparatus of claim 8, wherein the structure is further coated with a biodegradable, biocompatible polymer to provide for sustained release of the anticoagulant or antiplatelet drug.

10. The apparatus of claim 1, wherein the structure comprises reservoirs to hold an anticoagulant or antiplatelet drug.