Tissue thickness compensator for surgical staplers

1. A fastener cartridge, comprising:

a cartridge body comprising a deck and a plurality of fastener cavities;

a plurality of fasteners removably stored within said fastener cavities, wherein said fasteners are deployable from said fastener cavities to fasten tissue; and

a tissue thickness compensator positioned over said fastener cavities, wherein said tissue thickness compensator defines a single layer, wherein said tissue thickness compensator is configured to be captured within said fasteners, wherein said tissue thickness compensator is configured to adapt to the thickness of the tissue captured within said fasteners, and wherein said single layer of said tissue thickness compensator comprises:

a first compression zone having a first set of material properties; and

a second compression zone having a second set of material properties, wherein a property in said first set of material properties is different than a corresponding property in said second set of material properties, and wherein said first compression zone is spaced apart from said second compression zone.

2. The fastener cartridge of claim 1 , wherein said corresponding property is selected from the group consisting of density, stiffness, spring rate, durometer, and elasticity.

3. The fastener cartridge of claim 1 , wherein said fastener cavities are arranged in a first longitudinal row and a second longitudinal row, wherein said first compression zone is positioned over said first longitudinal row, and wherein said second compression zone is positioned over said second longitudinal row.

4. The fastener cartridge of claim 3 , wherein said first compression zone is also positioned over said second longitudinal row.

5. The fastener cartridge of claim 1 , wherein said first compression zone comprises a first layer and said second compression zone comprises a second layer.

6. The fastener cartridge of claim 1 , wherein said first compression zone and said second compression zone are comprised of a lyophilized material.

7. The fastener cartridge of claim 1 , wherein said first compression zone and said second compression zone are comprised of foam.

8. A fastener cartridge, comprising:

a cartridge body comprising:

a deck; and

a plurality of fastener cavities;

a plurality of fasteners removably stored within said fastener cavities, wherein said plurality of fasteners comprises a first group of fasteners and a second group of fasteners;

a tissue thickness compensator positioned over said deck, wherein said tissue thickness compensator defines a single layer, and wherein said single layer comprises:

a first portion comprising a first density, wherein said first group of fasteners is positioned to capture said first portion, and wherein said first portion is configured to adapt to the thickness of tissue captured within said fasteners of said first group of fasteners in a first manner; and

a second portion comprising a second density, wherein said second density is different than said first density, wherein said second group of fasteners is positioned to capture said second portion, wherein said second portion is configured to adapt to the thickness of tissue captured within said fasteners of said second group of fasteners in a second manner, wherein said second manner is different than said first manner, and wherein said first portion is spaced apart from said second portion.

9. The fastener cartridge of claim 8 , wherein said first portion comprises a first layer and said second portion comprises a second layer.

10. The fastener cartridge of claim 8 , wherein said first group of fasteners are positioned to capture said second portion.

11. A fastener cartridge, comprising:

a cartridge body comprising a deck and a plurality of fastener cavities;

a plurality of fasteners removably stored within said fastener cavities, wherein said plurality of fasteners comprises a first group of fasteners and a second group of fasteners;

a tissue thickness compensator positioned over said deck, comprising:

a first portion comprising a first density, wherein said first group of fasteners is positioned to capture said first portion, and wherein said first portion is configured to adapt to the thickness of tissue captured within said fasteners of said first group of fasteners in a first manner; and

a second portion comprising a second density, wherein said second density is different than said first density, wherein said second group of fasteners is positioned to capture said second portion, wherein said second portion is configured to adapt to the thickness of tissue captured within said fasteners of said second group of fasteners in a second manner, wherein said second manner is different than said first manner, and wherein said first group of fasteners are not positioned to capture said second portion, and wherein said second group of fasteners are not positioned to capture said first portion.

12. A fastener cartridge, comprising:

a cartridge body comprising a deck and a plurality of fastener cavities;

a plurality of fasteners removably stored within said fastener cavities, wherein said plurality of fasteners comprises a first group of fasteners and a second group of fasteners;

a tissue thickness compensator positioned over said deck, comprising:

a first portion comprising a first density, wherein said first group of fasteners is positioned to capture said first portion, and wherein said first portion is configured to adapt to the thickness of tissue captured within said fasteners of said first group of fasteners in a first manner; and

a second portion comprising a second density, wherein said second density is different than said first density, wherein said second group of fasteners is positioned to capture said second portion, wherein said second portion is configured to adapt to the thickness of tissue captured within said fasteners of said second group of fasteners in a second manner, and wherein said second manner is different than said first manner, and wherein said tissue thickness compensator comprises a heat-affected region.

13. An end effector, comprising:

an anvil;

a fastener cartridge, comprising:

a cartridge body comprising a deck and a plurality of fastener cavities; and

a plurality of fasteners removably stored within said fastener cavities, wherein said fasteners are deployable from said fastener cavities to fasten tissue; and

a tissue thickness compensator positioned intermediate said anvil and said fastener cartridge, wherein said tissue thickness compensator comprises a single layer, wherein said tissue thickness compensator is configured to be captured within said fasteners, wherein said tissue thickness compensator is configured to adapt to the thickness of the tissue captured within said fasteners, and wherein said single layer of said tissue thickness compensator comprises:

a first compression region having a first set of material properties; and

a second compression region having a second set of material properties, wherein a property in said first set of material properties is different than a corresponding property in said second set of material properties, and wherein said first compression region is spaced apart from said second compression region.

14. The end effector of claim 13 , wherein said corresponding property is selected from the group consisting of density, stiffness, spring rate, durometer, and elasticity.

15. The end effector of claim 13 , wherein said fastener cavities are arranged in a first longitudinal row and a second longitudinal row, wherein said first compression region is positioned over said first longitudinal row, and wherein said second compression region is positioned over said second longitudinal row.

16. The end effector of claim 15 , wherein said first compression region is also positioned over said second longitudinal row.

17. The end effector of claim 13 , wherein said first compression region comprises a first layer and said second compression region comprises a second layer.

18. The end effector of claim 13 , wherein said first compression region and said second compression region are comprised of a lyophilized material.

19. The end effector of claim 13 , wherein said first compression region and said second compression region are comprised of foam.

20. An end effector, comprising:

an anvil;

a fastener cartridge, comprising:

a cartridge body comprising a deck and a plurality of fastener cavities; and

a plurality of fasteners removably stored within said fastener cavities, wherein said fasteners are deployable from said fastener cavities to fasten tissue; and

a tissue thickness compensator positioned intermediate said anvil and said fastener cartridge, wherein said tissue thickness compensator is configured to be captured within said fasteners, wherein said tissue thickness compensator is configured to adapt to the thickness of the tissue captured within said fasteners, and wherein said tissue thickness compensator comprises:

a first compression region having a first set of material properties; and

a second compression region having a second set of material properties, wherein a property in said first set of material properties is different than a corresponding property in said second set of material properties; and

a heat-affected region.