Various methods and devices are described for retaining a medical implant within a body cavity. According to one aspect, at least a portion (16) of a medical implant is positioned within a body cavity, and a wall of the body cavity is re-shaped such that the re-shaped wall (14) prevents migration of the medical implant out of the body cavity. The re-shaped body wall may form a tissue pocket, tunnel, or other barrier against migration of the implant.
