Minimally invasive spinal surgical techniques and tools are provided. The methods include separating the iliocostalis lumborum muscle from the anterior leaf of the thoracolumbar fascia to create a channel from the patient's skin to the intertransverse interval. In one embodiment, the method also includes delivering graft material through the channel to the intertransverse interval. A device according to one aspect of the present invention includes a retraction portion having a flattened plate configured to atraumatically retract tissue to create a working space within an endosurgical site and a curved shaft attached to the retraction portion. The shaft includes a bend having a radius of preferably 160 degrees. A gripping portion is attached to the shaft and is configured for manually gripping and manipulating the device.