In general, invention is directed to devices for use in surgical procedures in which a medical implant is affixed to or implanted within an exterior surface of a body organ. A system, for example, is described that includes a cannula and a delivery instrument disposed within the cannula to fix a medical implant to an exterior surface of an organ. The delivery instrument has a distal end including a cavity and a vacuum port to draw a portion of the exterior surface of the organ into the cavity. The medical implant is affixed to the portion of the exterior surface drawn into the cavity of the delivery instrument.