Surgical access system and related methods

A system for forming a working corridor along a lateral, trans-psoas path to a targeted intervertebral disc of a lumbar spine, comprising:

• a trans-psoas dilator system, which includes at least a first dilator cannula, to create a tissue distraction corridor along the lateral, trans-psoas path through bodily tissue to the targeted intervertebral disc of the lumbar spine;
• an elongate member sized to be slidably received within the first dilator cannula and being deliverable to the targeted intervertebral disc along the lateral, trans-psoas path, at least one of the elongate member and the first dilator cannula having a maximum width smaller than the working corridor and also comprising a stimulation electrode along a distal region to deliver electrical stimulation for nerve monitoring when the stimulation electrode is positioned in the lateral, trans-psoas path, said at least one of the elongate member and the first dilator cannula defining a proximal electrical connector region for releasable electrical connection with a nerve monitoring system;
• and
• a bladed retractor assembly comprising a blade holder apparatus and a plurality of retractor blades that are simultaneously slidable over an outermost dilator cannula of the trans-psoas dilator system along the lateral, trans-psoas path to enlarge the tissue distraction corridor and form the working corridor along the lateral, trans-psoas path to the targeted intervertebral disc of the lumbar spine, wherein the blade holder apparatus is adjustable from a first position in which the plurality of retractor blades collectively define a cylindrical corridor to slide over the outermost dilator cannula of the trans-psoas dilator system to a second position in which the plurality of retractor blades are spaced apart from one another, wherein the bladed retractor assembly is configured to define the working corridor that is dimensioned so as to pass an implant through the working corridor along the lateral, trans-psoas path toward the targeted intervertebral disc of the lumbar spine.

A method of forming and using a working corridor along a lateral, trans-psoas path to a targeted intervertebral disc of a lumbar spine of a patient, comprising:

• inserting a trans-psoas dilator system into a patient along a lateral, trans-psoas path to create a distraction corridor along said lateral, trans-psoas path toward the targeted spinal disc of the lumbar spine, wherein first dilator cannula of the psoas dilator system is configured to receive an elongate member, wherein at least one instrument from a group consisting of the elongate member and the first dilator cannula comprises both:
• a maximum width smaller than the working corridor and a stimulation electrode along a distal region, and wherein said instrument also defines a proximal connector region for releasable electrical connection with a nerve monitoring system;
• outputting electrical stimulation from said stimulation electrode of said instrument from the group consisting of the elongate member and the first dilator cannula for nerve monitoring when said stimulation electrode is positioned in said lateral, trans-psoas path;
• simultaneously advancing a plurality of retractor blades of a bladed retractor assembly along said lateral, trans-psoas path and over a cylindrical exterior of an outermost dilator cannula of said trans-psoas dilator system, wherein the bladed refractor assembly is adjustable from a first position in which the plurality of retractor blades collectively define a cylindrical corridor to slide over the cylindrical exterior of the outermost dilator of said trans-psoas dilator system to a second position in which the plurality of retractor blades are spaced apart from one another;
• removing said of said trans-psoas dilator system from said patient after said plurality of retractor blades are advanced through the psoas muscle, wherein the working corridor along the lateral, trans-psoas path to the targeted spinal disc is at least partially defined by said plurality of retractor blades;
• and
• maintaining said working corridor along said lateral, trans-psoas path using said bladed retractor assembly while delivering a spinal implant through said working corridor to a disc space of the targeted intervertebral disc of the lumbar spine.