Patent ID: 7892173

Claim:
A method of accessing a surgical target site, comprising: delivering an elongate member to a spinal disc along a lateral, trans-psoas path to the lumbar spine such that a distal tip portion of the elongate member penetrates into an annulus of the spinal disc; advancing a dilator system along the lateral, trans-psoas path to the lumbar spine to create a distraction corridor, the dilator system comprising at least one dilator cannula that is configured to slidably engage with an exterior of the elongate member, the at least one dilator cannula being advanced to the spinal disc along the lateral, trans-psoas path to the lumbar spine, wherein at least one of the elongate member and the dilator cannula includes a stimulation electrode that outputs electrical stimulation for nerve monitoring during advancement of at least one of the elongate member and the dilator cannula along the lateral, trans-psoas path to the lumbar spine; slidably advancing a three-bladed retractor assembly over the dilator system toward the spinal disc along the lateral, trans-psoas path, the three-bladed retractor assembly including a posterior-most retractor blade, a caudal-most retractor blade, and a cephalad-most retractor blade that extend generally perpendicularly relative to arm members of a handle assembly, wherein the caudal-most retractor blade and the cephalad-most retractor blade are movable relative to the posterior-most retractor blade in response to pivoting movement of two of the arm members of the handle assembly, and wherein the three-bladed retractor assembly is slidably advanced over the dilator system when in a closed position in which the retractor blades are generally adjacent to one another; releasably engaging a posterior shim element with grooves along an inner face of the posterior-most retractor blade so that at least a portion of the posterior shim element extends distally from the posterior-most retractor blade and anchors into the spinal disc; actuating the handle assembly to adjust the three-bladed retractor assembly to an opened position in which the caudal-most retractor blade and the cephalad-most retractor blade are moved away from the posterior-most retractor blade to enlarge the distraction corridor and form an operative corridor along the lateral, trans-psoas path to the lumbar spine; releasably engaging a first retractor blade extender with grooves along an inner face of the caudal-most retractor blade so that at least a portion of the first retractor blade extender protrudes from the caudal-most retractor blade; releasably engaging a second retractor blade extender with grooves along an inner face of the cephalad-most retractor blade so that at least a portion of the second retractor blade extender protrudes from the cephalad-most retractor blade; and inserting an implant through the operative corridor formed by the three-bladed retractor assembly along the lateral, trans-psoas path to the lumbar spine.