Lateral access system for the lumbar spine

A minimally invasive dilation device includes a plurality of rigid arms radially arrayed about a center and a dilating member positioned between the arms. A stylus may occupy the center. An outer flexible sleeve may be circumferentially secured to the arms, lying within or without the plurality of arms. An inner mesh may surround the stylus and dilating member. The device may be introduced into tissue toward a targeted area, while in a closed configuration. The dilating member may be a balloon, wherein upon inflation of the balloon, the arms are pushed radially outward, expanding the device and dilating the surrounding tissue. The dilating member may be a tube, wherein upon insertion of the tube, the arms are pushed radially outward. A cannula may be inserted inside the plurality of arms to keep the arms in an open configuration, and the dilating member may be withdrawn, providing an open passageway through the device to the targeted area. The device may be used with a neural monitoring system.