A delivery apparatus , comprising: a steerable shaft comprising a proximal portion , a distal portion , and a first pull-wire conduit and a second pull-wire conduit each extending at least partially through the proximal and distal portions of the shaft , the second pull-wire conduit disposed adjacent the first pull-wire conduit ; a first pull wire extending through the first pull-wire conduit and a second pull wire extending through the second pull-wire conduit , the first and second pull wires each having a distal end portion fixed to the distal portion of the shaft and a proximal end portion; an adjustment mechanism operatively connected to the proximal end portion of the first and second pull wires and configured to increase and decrease tension in the first and second pull wires to adjust the curvature of the distal portion of the shaft ; wherein the shaft comprises a first inner layer that defines an inner diameter of the shaft and a second outer layer that defines an outer diameter of the shaft , the distal portion of the shaft comprising a steerable portion including a compression-resistance portion located opposite the first and second pull-wire conduits and incorporated into the second outer layer of the steerable portion , the first inner layer defining a recess configured to receive the first and second pull-wire conduits , the compression-resistance portion extending angularly along a portion of a cross-section of the second outer layer , the second outer layer of the steerable portion having a first hardness, the compression-resistance portion having a second hardness that is greater than the first hardness. a steerable shaft comprising a proximal portion , a distal portion , and a first pull-wire conduit and a second pull-wire conduit each extending at least partially through the proximal and distal portions of the shaft , the second pull-wire conduit disposed adjacent the first pull-wire conduit ; a first pull wire extending through the first pull-wire conduit and a second pull wire extending through the second pull-wire conduit , the first and second pull wires each having a distal end portion fixed to the distal portion of the shaft and a proximal end portion; an adjustment mechanism operatively connected to the proximal end portion of the first and second pull wires and configured to increase and decrease tension in the first and second pull wires to adjust the curvature of the distal portion of the shaft ; wherein the shaft comprises a first inner layer that defines an inner diameter of the shaft and a second outer layer that defines an outer diameter of the shaft , the distal portion of the shaft comprising a steerable portion including a compression-resistance portion located opposite the first and second pull-wire conduits and incorporated into the second outer layer of the steerable portion , the first inner layer defining a recess configured to receive the first and second pull-wire conduits , the compression-resistance portion extending angularly along a portion of a cross-section of the second outer layer , the second outer layer of the steerable portion having a first hardness, the compression-resistance portion having a second hardness that is greater than the first hardness. <EOS>