Valve introducer systems and methods for implanting heart valve prostheses are disclosed, where a valve introducer includes an adjustable deployment mechanism comprising a deployment element and an implantation depth controlling element having a distal end and an adjustable length. The valve introducer also includes a tubular member having a distal end, configured to deliver a heart valve prosthesis, and a length extending from a fixed reference point. The implantation depth controlling element can comprise an inner and an outer cylinder, such as where the outer cylinder has interior threads, and the inner cylinder has exterior threads. The adjustable deployment element can include a depth gauge, wherein the depth gauge indicates the length the tubular member extends beyond a fixed reference point. In certain embodiments, the adjustable deployment element can also be configured to be secured to a cannula.