A delivery apparatus includes a steerable shaft having a proximal portion, a distal portion, and a pull-wire conduit that extends through the proximal and distal portions. A pull wire extends through the conduit and has a distal portion that is fixed to the shaft. An adjustment mechanism is connected to the proximal end portion of the pull wire and configured to increase and decrease tension in the pull wire to adjust the curvature of the shaft. The distal portion of the shaft has a steerable portion including one or more layers. A compression-resistance portion is incorporated into a layer of the steerable portion, and extends angularly along a portion of a cross-section of the layer. The layer of the steerable portion into which the compression-resistance portion is incorporated has a first hardness, and the compression-resistance portion has a second hardness that is greater than the first hardness.
