Method for polishing surgical stents

• US 6,537,202 B1
• Filed: 05/05/1998
• Issued: 03/25/2003
• Est. Priority Date: 06/06/1997
• Status: Expired due to Term

• Current Assignee: Cook Medical Incorporated (Cook Group Incorporated)
• Original Assignee: Cook Incorporated (Cook Group Incorporated)
• Inventors: Frantzen, John J.
• Primary Examiner(s): PREBILIC, PAUL B
• Application Number:
  US09/072,605
• Time in Patent Office: 1,785 Days
• Field of Search: 451/36, 451/104, 451/113, 451/40, 451/89, 623/1, 623/12, 623/901, 623/1.15, 623/23.7, 623/920, 623/921, 606/198, 600/36
• US Class Current: 600/36
• 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 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/068 Modifying the blood flow model, e.g. by diffuser or deflector
• CPC Class Codes: A61F 2002/91541 Adjacent bands are arranged out of phase
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2002/91566 connected trough to trough
• CPC Class Codes: A61F 2240/001 Designing or manufacturing processes
• CPC Class Codes: B24B 31/003 whereby the workpieces are mounted on a holder and are immersed in the abrasive material
• CPC Class Codes: B24B 31/116 using plastically deformable grinding compound, moved relatively to the workpiece under the influence of pressure
• CPC Class Codes: B24C 3/32 designed for abrasive blasting of particular work, e.g. the internal surfaces of cylinder blocks B24C3/08, B24C3/18 take precedence
• CPC Class Codes: B24C 3/327 by an axially-moving flow of abrasive particles without passing a blast gun, impeller or the like along the internal surface polishing or abrading surfaces using plastically deformable grinding compound, moved relatively to the workpiece under the influence of pressure B24B31/116
• CPC Class Codes: B24C 5/005 Vibratory devices, e.g. for generating abrasive blasts by ultrasonic vibrations sonic cleaning in general B08B3/12
• CPC Class Codes: Y10S 623/901 Method of manufacturing prosthetic device
• CPC Class Codes: Y10S 623/921 Blood vessel

Abstract

A method for polishing radially expandable surgical stents is disclosed where fluid abrasive media M flows over surfaces of the stent 10 causing the surfaces of the stent 10 to be polished and streamlined. The stent 10 is temporarily provided with cylindrical support ends 20, which are not radially expandable to support the stent 10 during the polishing process. An interior polishing fixture 100 is provided which has cylindrical chambers 135 therein adapted to receive a stent 10 therein. Fluid abrasive media M then flows into bores 108 in the fixture 100 leading to the cylindrical chambers 135 and adjacent the inner diameter surfaces of the stent 10. Surfaces of the stent 10 forming the outer diameter are polished by placing the stent 10 within an exterior polishing fixture 200 which has a cylindrical recess 220 therein. The cylindrical recess 220 has a diameter greater than a diameter of outer surfaces of the stent 10 and includes a cylindrical shaft 270 passing axially through the cylindrical recess 220 upon which the stent 10 is located. Slanted bores 208 pass through walls of the exterior polishing fixture 200 and into the cylindrical recess 220, directing the abrasive media M adjacent exterior surfaces of the stent 10 and causing polishing of the exterior surfaces of the stent 10. The direction of abrasive media M flow can be reversed to make streamlining of segments of the stent 10 occur in a symmetrical fashion. After polishing of the stent 10 is completed, the cylindrical support ends 20 are removed and the stent 10 is ready for implantation and radial expansion within a body lumen L. When polished and streamlined, the radially expandable surgical stent 10 more effectively supports a body lumen L without excessive thrombus, restenosis and other medical complications.

Claims

1. A method for polishing surfaces of a cylindrical radially expandable surgical stent including the steps of:

selecting an abrasiveness for particles within a fluid abrasive media;

providing a source of the fluid abrasive media;

orienting the radially expandable surgical stent with a central axis thereof extending in an axial direction;

subjecting the fluid abrasive media to elevated pressure substantially between 300 and 800 p.s.i.; and

flowing the abrasive media past the radially expandable surgical stent in an axial direction with the abrasive media coming into physical contact with the surface of the radially expandable surgical stent, wherein the step of flowing includes maintaining the flowing past an inner stent surface for a length of time sufficient to abrade the edges of the inner stent surface until said edges are streamlined in shape, and maintaining the flowing past an outer stent surface for a length of time sufficient only to polish the outer stent surface.

2. A method for polishing surfaces of a cylindrical radially expandable surgical stent including the steps of:

selecting an abrasiveness for particles within a fluid abrasive media;

providing a source of the fluid abrasive media;

orienting the radially expandable surgical stent with a central axis thereof extending in an axial direction;

subjecting the fluid abrasive media to elevated pressure substantially between 300 and 800 p.s.i.; and

flowing the abrasive media past the radially expandable surgical stent in an axial direction with the abrasive media coming into physical contact with the surface of the radially expandable surgical stent, wherein the step of flowing includes maintaining the flowing for a length of time sufficient to abrade the edges of an inner stent surface until said edges have a greater radii of curvature than radii of curvature of outer edges bordering an outer surface of the stent.

3. A method for polishing surfaces of a cylindrical radially expandable surgical stent having a central axis, comprising:

providing a source of the fluid abrasive media;

flowing the abrasive media past the stent in an axial direction with the abrasive media coming into physical contact with the surfaces of the stent; and

maintaining the flowing past an inner stent surface for a length of time sufficient to abrade the edges of the inner stent surface until said edges are streamlined in shape, wherein the flowing of the abrasive media past an outer stent surface is maintained for a length of time sufficient only to polish the outer stent surface.

4. A method for polishing surfaces of a cylindrical radially expandable surgical stent having a central axis, comprising:

providing a source of the fluid abrasive media;

flowing the abrasive media past the stent in an axial direction with the abrasive media coming into physical contact with the surfaces of the stent; and

maintaining the flowing past an inner stent surface for a length of time sufficient to abrade the edges of the inner stent surface until said edges are streamlined in shape, wherein the step of flowing includes maintaining the flowing for a length of time sufficient to abrade the edges of an inner stent surface until said edges have a greater radii of curvature than radii of curvature of outer edges bordering an outer surface of the stent.

5. A method for polishing surfaces of a cylindrical radially expandable surgical stent having a central axis, comprising:

providing a fluid abrasive media containing particles having a size substantially between 0.0003 and 0.008 inches;

providing a source of the fluid abrasive media;

maintaining the fluid abrasive media at an elevated pressure substantially between 300 and 800 p.s.i.;

flowing the abrasive media past the stent in an axial direction with the abrasive media coming into physical contact with the surfaces of the stent;

maintaining the flowing past an inner stent surface for a length of time sufficient to abrade the edges of the inner stent surface until said edges are streamlined in shape; and

maintaining the flowing past an outer stent surface for a length of time sufficient to polish the outer stent surface.