A fastener for attaching a sheet-like implant to tissue or bone may be provided with a first arm having a proximal end and a distal end, a second arm having a proximal end and a distal end, and a bridge extending therebetween. Each of the first and second arms include a trunk portion defining at least a portion thereof, the trunk portion having a lateral extent larger than a lateral extent of the bridge or non-trunk portion of the arm adjacent thereto and can be mounted eccentrically to the bridge or non-trunk portion of the arm adjacent thereto such that the staple includes a first change in lateral stiffness disposed proximate the bridge or non-trunk portion of the arm abutment with the trunk. Fastener delivery devices and methods are also disclosed.
