Tissue fastening devices and processes that promote tissue adhesion

The invention in certain aspects relates to a surgical fastener for fastening tissue segments having tissue surfaces. The fastener includes a first fastener member having a base and a piercing element connected to the base for piercing the tissue segments to be fastened, a second fastener member having an opening for receiving and retaining the piercing element of the first fastener member such that the tissue segments to be fastened are retained between the first and second fastening members, and means for promoting adhesion between the tissue surfaces. The invention also relates to related methods and devices for promoting adhesion of tissue segments and preventing fastener migration, especially in an endoscopic procedure for the treatment of GERD.