Patent ID: 8790406

Claim:
A method for accessing the L5/S1 disc of the lumbosacral junction, comprising the steps of: creating an access hole through the ilium; advancing an initial dilator through the access hole and towards the L5/S1 disc while and electrical stimulation signal is delivered from a stimulation electrode on the distal end of the initial dilator; assessing the neuromuscular response to the stimulation signal to indicate the proximity of the L5/S1 nerve root to the distal end of the initial dilator; directing the distal end of the dilator closer to the L5/S1 nerve root until the neuromuscular response indicates that the distal end of the initial dilator is next to but not contacting the L5 nerve root; advancing the distal end of the initial dilator through a safe zone between the L5 nerve root and the iliac vein to the L5/S1 disc; and advancing at least one supplemental dilator over the initial dilator through the access hole and safe zone to the L5/S1 disc; and removing all but the outermost dilator.