An instrument for deploying a cardiac valve prosthesis, including a plurality of radially expandable portions, at an implantation site, includes a plurality of deployment elements each independently operable to obtain the radial expansion of a radially expandable portion of the valve prosthesis. Additionally, the instrument is adapted to provide a de-aired, fluid-filled, or gas filled environment in order to minimize and/or prevent air embolism during the implantation procedure. The fluid can contain a drug. A method for deploying the cardiac valve prosthesis includes advancing the instrument to an implant site and independently actuating the radially expandable portions.