Surgical stapling system comprising a grooved forming pocket

1. An end effector of a surgical stapling instrument, comprising:

a staple cartridge, comprising:

a cartridge body including a deck; and

staples removably stored in said cartridge body, wherein each said staple comprises:

a base;

a first leg extending from said base; and

a second leg extending from said base; and

an anvil, comprising:

a tissue compression surface; and

forming pockets defined in said tissue compression surface, wherein said forming pockets comprise:

a first forming pocket, comprising:

a first end configured to receive said first leg;

a second end;

a central longitudinal axis extending between said first end and said second end;

a concave turning surface extending between said first end and said second end; and

a groove defined in said concave turning surface, wherein said groove is laterally offset from said central longitudinal axis; and

a second forming pocket, comprising:

a first end configured to receive said second leg;

a second end;

a central longitudinal axis extending between said first end and said second end of said second forming pocket;

a concave turning surface extending between said first end and said second end of said second forming pocket; and

a groove defined in said concave turning surface of said second forming pocket, wherein said groove of said second forming pocket is laterally offset from said central longitudinal axis of said second forming pocket in the same direction as said groove of said first forming pocket.

2. The end effector of claim 1 , wherein each said groove is parallel to each said central longitudinal axis.

3. The end effector of claim 1 , wherein each said groove extends between each said first end and each said second end of each said forming pocket.

4. The end effector of claim 1 , wherein each said turning surface comprises a bottom of each said forming pocket, and wherein each said groove is deeper than each said bottom.

5. The end effector of claim 1 , wherein said grooves of said forming pockets are aligned with one another.

6. The end effector of claim 1 , wherein said forming pockets are arranged in an annular array, and wherein said groove of each said forming pocket is positioned along a circumference.

7. An end effector for use with a surgical fastening instrument, comprising:

a staple cartridge, comprising:

a cartridge body including a deck; and

fasteners removably stored in said cartridge body, wherein each said fastener comprises:

a base;

a proximal leg extending from said base; and

a distal leg extending from said base; and

an anvil, comprising:

a tissue compression surface;

a pair of forming pockets defined in said tissue compression surface, wherein said pair of forming pockets is configured to deform a said proximal leg and a said distal leg of a said fastener, and wherein each said forming pocket of said pair of forming pockets comprises:

a first end configured to receive a said leg;

a second end;

a central axis extending between said first end and said second end;

a concave turning surface extending between said first end and said second end; and

a channel defined in said concave turning surface, wherein said channel is laterally offset from said central axis,

wherein each said channel of each said forming pocket of said pair of forming pockets is laterally offset from each said central axis in the same direction.

8. The end effector of claim 7 , wherein said channel is parallel to said central axis.

9. The end effector of claim 7 , wherein said channel extends between said first end and said second end of said forming pocket.

10. The end effector of claim 7 , wherein said turning surface comprises a bottom of said forming pocket, and wherein said channel is deeper than said bottom.

11. The end effector of claim 7 , wherein said channels of said forming pockets are aligned with one another.

12. The end effector of claim 7 , wherein said forming pockets are arranged in an annular array, and wherein said channel of each said forming pocket is positioned along a circumference.

13. An anvil of a surgical fastening instrument, comprising:

a tissue compression surface; and

forming pockets defined in said tissue compression surface, wherein said forming pockets comprises a pair of forming pockets configured to deform a first leg and a second leg of a fastener, and wherein each said forming pocket of said pair of forming pockets comprises:

a first end configured to receive a said leg;

a second end;

a central axis extending between said first end and said second end, wherein said central axis defines a first side of each said forming pocket and a second side of each said forming pocket;

a concave turning surface extending between said first end and said second end; and

a channel defined in said concave turning surface, wherein said channel is laterally offset from said central axis,

wherein each said channel of each said forming pocket of said pair of forming pockets is positioned on the same side of each said forming pocket.

14. The anvil of claim 13 , wherein said channel is parallel to said central axis.

15. The anvil of claim 13 , wherein said channel extends between said first end and said second end of said forming pocket.

16. The anvil of claim 13 , wherein said turning surface comprises a bottom of said forming pocket, and wherein said channel is deeper than said bottom.

17. The anvil of claim 13 , wherein said channels of said forming pockets are aligned with one another.

18. The anvil of claim 13 , wherein said forming pockets are arranged in an annular array, and wherein said channel of each said forming pocket is positioned along a circumference.