A handle assembly for a prosthesis delivery device includes a proximal gripping portion, a stationary gripping portion, a shell assembly including first shell portion and a second shell portion extending distally from the proximal gripping portion to the stationary gripping portion when the proximal gripping portion is in a first position. The first shell portion and the second shell portion each have a part-cylindrical shape and complement each other to form a cylindrical shell assembly. Absent the first shell portion and the second shell portion being in the assembled state, the proximal gripping portion is distally movable toward the stationary gripping portion from the first position to a second position. The first position is a pre-deployment position and the second position is a deployment position. The first shell portion and second shell portion block the proximal gripping portion from moving distally from the first position into the second position.
