Tissue cutting die

• US 5,425,741 A
• Filed: 12/17/1993
• Issued: 06/20/1995
• Est. Priority Date: 12/17/1993
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Autogenics Co.
• Inventors: Hudak, Philip J., Love, Charles S., Lemp, Steven K.
• Primary Examiner(s): Pellegrino, Stephen C.
• Assistant Examiner(s): Lewis, William W.
• Application Number:
  US08/169,620
• Time in Patent Office: 550 Days
• Field of Search: 606/167, 606/184, 606/166, 606/131, 606/132, 128/750-758, 128/858, 30/301, 30/316, 30/358, 83/531, 83/541, 623/2
• US Class Current: 606/167
• CPC Class Codes: A61B 17/32 Surgical cutting instruments A61B18/042 takes precedence; suture cutters A61B17/0467; instruments for ligaturing or cutting A61B17/128; instruments for rupturing the amniotic membrane A61B17/4208; specially adapted knives for eye surgery A61F9/0133
• CPC Class Codes: A61B 17/322 Skin grafting apparatus
• CPC Class Codes: A61B 2017/00783 Valvuloplasty
• CPC Class Codes: A61B 2017/320052 Guides for cutting instruments
• CPC Class Codes: A61F 2/2415 Manufacturing methods

Abstract

The present invention provides a novel tissue cutting device for autologous tissue heart valves which accurately cuts the tissue to a predetermined configuration in a minimal amount of time. The disposable tissue cutting die of the present invention is comprised of a cover, a base member, a continuous blade enclosing a desired spatial configuration and an actuator for forcing said tissue against the entire perimeter of the blade.

Claims

1. An apparatus for cutting tissue to be used in a heart valve, said heart valve having an inner stent configured with a plurality of posts, each of said posts including outwardly-projecting tissue alignment members, and an outer stent having a plurality of posts and an expandable base with tensioning means, said inner stem positioned inside said outer stent, said outer stem tensioning means providing a clamping force securing said inner stent, said apparatus comprising:

a cover including a top member having a center length, said top member provided with a channel along said center length, said top member further including a raised island in said channel, said island having a shape corresponding to the spatial configuration into which the tissue will be cut, said island including a plurality of raised ferrules positioned to cut holes into the tissue in locations corresponding to said tissue alignment members on said inner stent, and an insert fitting within said channel, said insert containing a cutout for receiving said island, said insert completely surrounding said island and creating a narrow gap between said insert and said island when said insert is inserted into said top member, said top members and said island having a generally planar surface;

a blade with a razor sharpened edge positioned into said gap between said insert and said island, said blade edge extending above the generally planar surface of said top members and said island;

a base member removably securable to said cover during operation of said apparatus and including a base piece having a center length parallel to said center length of said cover when said base and said cover are secured together and top and bottom surfaces, said base piece having a channel along said center length, said base piece further including a flexible sheet secured to the top surface of said base piece by a plurality of securing members, the union of said base piece and said flexible sheet creating a tunnel therebetween;

an actuator member slidably mounted in said tunnel, said actuator having first and second ends, a raised portion formed near said first end and a flat region formed near said second end, said raised portion forcing a proximal portion of said flexible sheet against the top of said blade as said actuator member is translated through said tunnel so that tissue retained between said blade and said flexible sheet is automatically cut through when said actuator member is translated through said tunnel; and

a plurality of attachments removably secured to said cover and said base and provided to secure said cover and said base member together.

2. The apparatus of claim 1 wherein said insert of said cover further comprises:

a plurality of holes formed at the corners of said cutout for receiving said island, said blade extending into said holes to allow the outline of said cut tissue to be continuous when said tissue is cut.

3. The apparatus of claim 1 wherein said top member is made of a translucent polycarbonate material.

4. The apparatus of claim 1 wherein said insert is made of a semi-translucent polycarbonate material.

5. The apparatus of claim 1 wherein said island and said insert form a gap of 0.002 inch or less.

6. The apparatus of claim 1 wherein said blade is rectangular in shape and flexible.

7. The apparatus of claim 1 wherein said blade is made of a high quality corrosion resistant material, such as stainless steel, with a razor sharpened edge.

8. The apparatus of claim 1 wherein said blade is 0.006 inch thick.

9. The apparatus of claim 1 wherein said blade extends 35 mils above said generally planar surface of said top members and said island.

10. The apparatus of claim 1 wherein said blade is comprised of four separate blades.

11. The apparatus of claim 1 wherein said ferrules extend 35 mils above the generally planar surface of said island.

12. The apparatus of claim 1 wherein said base piece of said base member is made of a translucent polycarbonate material.

13. The apparatus of claim 1 wherein said flexible sheet is made of TEFLON.

14. The apparatus of claim 1 wherein said slide is made of thermoplastic material.

15. The apparatus of claim 1 wherein said attachments are wing nuts.

16. An apparatus for quickly and precisely cutting a piece of autologous, homologous or heterologous tissue to a desired spatial configuration, said apparatus applying a consistent cutting force substantially independent of the force applied by the operator so that the tissue is substantially completely and automatically cut through along the perimeter of said desired spatial configuration, said apparatus comprising:

a cover having a generally planar surface;

a blade defining the perimeter of the desired spatial configuration, said blade retained in said cover and extending above the generally planar surface of said cover a length approximately equal to the thickness of the tissue to be cut;

a base member underlying and removably attachable to said cover;

a slide member slidably retained by said base member for applying a force against the entire perimeter of said blade as said slide is translated with respect to said base member along the perimeter of said blade so that a piece of tissue laid between said blade of said cover and said base member will be precisely cut substantially along the entire perimeter of said blade.

17. An apparatus for quickly and precisely cutting a piece of autologous, homologous or heterologous tissue to a desired spatial configuration, said apparatus applying a consistent cutting force substantially independent of the force applied by the operator so that the tissue is substantially completely cut through along the perimeter of said desired spatial configuration, said apparatus comprising:

a base member;

a cover member juxtaposed with said base member so that said tissue is retained between said base member and said cover member;

a blade defining the perimeter of the desired spatial configuration, said blade supported by said cover member; and

an actuator member slidably mounted with respect to said base member and said cover member, said actuator member sequentially forcing segments of said retained tissue against said blade as said actuating member is moved with respect to said base and cover members so that said piece of tissue is cut through by shearing along the entire perimeter of said blade.

18. An apparatus for cutting tissue, comprising:

a cover having a top member with a center length and a channel having a raised island portion, said channel and island disposed along said center length, said cover further including an insert having a plurality of corners and a cutout conforming to said island, and a plurality of blades disposed between said insert and said island, at least a portion of said blades projecting above said island;

a base member having a base piece with a center length and a channel disposed along said center length, said base member including a flexible sheet secured to said base piece, said base piece and said flexible sheet forming a tunnel when secured together;

a slide slidably mounted in said base member and having first and second ends and a raised portion on said first end; and

a plurality of attachments removably affixed to said cover and said base and provided to secure said cover and said base member together.

19. The apparatus of claim 18 wherein said insert of said cover further comprises:

a plurality of holes formed at the corners of said cutout for receiving said island, said blades extending into said holes to allow the outline of said tissue to be continuous when said tissue is cut.

20. The apparatus of claim 18 wherein said attachments are wing nuts.

21. An apparatus for cutting tissue, comprising:

a cover having a top member with a center length and a channel having a raised island portion disposed along said center length, said cover further including an insert having a cutout conforming to said island and a plurality of corners and a one piece blade disposed between said insert and said island, wherein a plurality of holes is formed at the corners of said cutout for receiving said island to allow said blade to bend around the corners of said island to allow the outline of said tissue to be continuous when said tissue is cut;

a base member removable securable to said cover and having a base piece with a center length and a channel disposed along said center length, said base piece further comprising a flexible sheet secured to said base piece, said base piece and said flexible sheet forming a tunnel;

a slide having first and second ends and a raised portion on said first end; and

a plurality of attachments removably affixed to said base and cover and provided to secure said cover and said base member together.

22. A method for precisely, repeatably cutting a piece of tissue into a predetermined shape comprising the steps of:

providing a roughly sized piece of tissue;

providing a tissue cutting die having a cover having raised blades for cutting said piece of tissue and a base member having a flexible sheet with top and bottom surfaces, said flexible sheet forming a tunnel in said base member;

laying said roughly sized piece of tissue flat across said top surface of said flexible sheet;

assembling said cover and base member of said tissue cutting die together and securing said cover and base member to each other;

providing a slide having a first end portion including a raised portion and a flat second end portion;

inserting said second end portion of said slide into said tunnel formed by said flexible sheet;

pulling said second end portion of said slide through said tunnel, allowing said raised portion of said slide to push against said bottom surface of the flexible sheet, causing said tissue to be pushed against the blades of said cover; and

disassembling said cover and base member and removing said tissue therefrom.

23. The method of claim 22 wherein said blades cut said tissue by shearing.

24. The method of claim 23 wherein said shearing is caused by said raised portion of said slide producing a wave in said tissue to sequentially push portions of said tissue into said blade as said slide is pulled through said tunnel.

25. An apparatus for cutting tissue into a predetermined shape, comprising:

a cover comprising a top member with a plurality of blades embedded into said top member;

a base member removably securable to said cover and having a base piece with a center length and a channel disposed along said center length, said base piece further comprising a flexible sheet secured to said base piece, said base piece and said flexible sheet forming a tunnel;

a slide slidably mounted in said base member and having first and second ends and a raised portion on said first end; and

a plurality of attachments removably securable to said cover and said base and provided to secure said cover and said base member together.

26. The apparatus of claim 25 wherein said blades are configured in said top member such that said blades form a shape identical to the shape into which the tissue will be cut.