Surgical stapler apparatus

Claim 1

An anvil for clinching the ends of a U-shaped surgical staple in a surgical stapler comprising: a main channel formed in the surface of the anvil and having a longitudinal axis transverse to the longitudinal axis of the base of the U-shaped surgical staple to be clinched against the anvil, the length of the main channel being at least several times greater than the cross sectional dimension of the staple measured parallel to the longitudinal axis of the main channel, the main channel including a plurality of subordinate secondary channels formed in the surface of the main channel, each secondary channel having a longitudinal axis transverse to the longitudinal axis of the main channel and extending lengthwise across the width of the main channel, the secondary channels being laterally immediately adjacent and substantially parallel to one another, the width of each secondary channel being substantially less than the length of the main channel, the depth of each secondary channel measured from the bottom of the main channel to the bottom of the secondary channel being substantially less than the depth of the main channel measured from the top of the main channel to the bottom of the main channel so that all parts of all of the secondary channels, including the boundaries between laterally adjacent secondary channels, are recessed within the main channel, and the width and depth of each secondary channel being great enough to receive and guide the end of the staple substantially parallel to the longitudinal axis of the secondary channel during clinching of the staple.