Patent ID: 8192357

Claim:
A system for accessing a spinal disc of a lumbar spine through an operative corridor, comprising: an initial dilating cannula configured to create a tissue distraction corridor to a lumbar spine, wherein said initial dilating cannula is deliverable to a spinal disc along a lateral, trans-psoas path to the lumbar spine, the distal tip region of the initial dilating cannula including a stimulation electrode exposed along a tapered outer surface that is angled relative to a longitudinal axis of said initial dilating cannula such that the stimulation electrode delivers electrical stimulation away from the distal tip region for nerve monitoring when the initial dilating cannula is positioned in the lateral, trans-psoas path, a secondary distraction assembly comprising a plurality of dilators of sequentially larger width deliverable to the spinal disc along the lateral, trans-psoas path; and a refraction assembly comprising a mounting structure and four refractor blades releasably attachable to said mounting structure, wherein said retraction assembly is configured to maintain an operative corridor along the lateral, trans-psoas path to the lumbar spine that is enlarged from the tissue distraction corridor along the lateral, trans-psoas path to the lumbar spine, wherein, when the four retractor blades are positioned along the lateral, trans-psoas path, a first of the four retractor blades is a posterior-most retractor blade, a second of the four retractor blades is an anterior-most retractor blade, a third of the four retractor blades is a caudal-most retractor blade, and a fourth of the four retractor blades is a cephalad-most retractor blade, wherein said posterior-most retractor blade is spaced apart from said anterior-most retractor blade when said four retractor blades maintain the operative corridor along the lateral, trans-psoas path to the lumbar spine, wherein the operative corridor is dimensioned so as to pass an implant through the operative corridor along the lateral, trans-psoas path to the lumbar spine.