Surgical access system and related methods

A system for forming a customized lateral, trans-psoas operative corridor along a far-lateral approach to a targeted intervertebral disc of a lumbar spine, comprising:

• trans-psoas dilation means for dilating a lateral, trans-psoas path in a far-lateral approach to a targeted intervertebral disc of a lumbar spine, at least a portion of the trans-psoas dilation means for dilating the lateral, trans-psoas path comprising a means for delivering an electrical stimulation current to tissue adjacent to the lateral, trans-psoas path sufficient to innervate leg muscle groups;
• trans-psoas retraction means for advancing along an exterior of the trans-psoas dilation means and for creating a customized lateral, trans-psoas operative corridor along the far-lateral approach to a lateral-most aspect of the targeted intervertebral disc of a lumbar spine, the trans-psoas retraction means including:
• cephalad-most means for engaging and retracting a cephalad-most portion of the tissue adjacent to the lateral, trans-psoas path;
• caudal-most means for engaging and retracting a caudal-most portion of the tissue adjacent to the lateral, trans-psoas path;
• a holder means for holding the cephalad-most means and the caudal-most means and for adjusting the cephalad-most means and the caudal-most means from a first position in which the cephalad-most means and the caudal-most means are simultaneously insertable along the exterior of the trans-psoas dilation means to a second position in which the cephalad-most means and the caudal-most means are spaced further apart from one another relative to the first position, wherein the holder means is configured to pivot the cephalad-most means and the caudal-most means relative to one another while the cephalad-most means and the caudal-most means engage said portions of the tissue adjacent to the lateral, trans-psoas path, wherein the holder means further comprises a rotatable actuation means for customizing a cross-sectional shape of the lateral, trans-psoas operative corridor along the far-lateral approach so that the customized lateral, trans-psoas operative corridor is dimensioned to pass an implant device therethrough;
• and
• a spinal fusion implant to insert through the customized lateral, trans-psoas operative corridor and having a construction comprising plastic and metal.