Caspar Micro Lumbar Discectomy Retractor Set Of Spinal Surgery Retractors is a surgical tool is used in spinal procedures to gain access to the lumbar spine. It is intended to pull back muscles and soft tissue. Lumbar discectomy is a surgical intervention aimed at removing part of a herniated or damaged intervertebral disc in the lumbar (lower back) region to relieve pressure on the spinal nerves.