The basis for any microsurgical procedure is the use of magnification and bright illumination of the operative field.  This can be provided to a satisfactory degree by use of an operative microscope, operative magnifying loupes, and fiberoptic head lamp.  A primary advantage of microsurgery is a reduction of tissue trauma, a decrease in operative recovery, and a reduction of postsurgical scarring and opertive trauma.  A number of techniques, such as micro endoscopic visualization and laser assisted disc resection have been employed.  While these techniques may be of benefit in selected patients, they have not been shown to substantially change or improve the fundamental microdiscectomy procedure.  Microsurgery can be performed at one or more levels, either unilaterally (one side), or bilaterally (both sides).   Obviously, the primary benefits diminish as the number of levels increase due to the exposure necessary to address each level.

The basic unilateral, one level microdiscectomy for a herniated disc is performed as follows.  An approximately 1 inch or less incision is made, overlying the disc space in the skin as determined by an intraoperative x-ray.  The fatty tissue beneath the skin is then divided to the dorsal fascia which is the thick tissue overlying the muscle above the spine.  This fascia is then incised and the musculature swept to the side revealing the underlying bone and ligaments.  The spinal canal is entered by resection of the ligamentum flavum which is the ligament connecting between the lamina of each vertebra.  The lamina are the flat areas of bone overlying the top of the canal at each level.  A small portion of the edge of thelamina above and delow may also be resected with the ligaments to allow adequate exposure of the underlying nerve root and disc.  Once the canal has been exposed, the nerve root overlying the disc identified and gently moved to the center of the canal and held with a retractor.  The herniated disc cna thern be visualized.   Small veins are coagulated to minimize bleeding.  The thin veil of ligaments overlying the herniation is incised and probes are used to dislodge the nuclear material.   This material is then removed with graspers until the nucleus is noted to be empty of any free fragment material.  Typically, the majority of the volume of the disc is left with removal of only the loose fragments.  Once verification has been assured that the disc herniation has been removed and no further pressure exists on the nerve root, the retractors are removed.  A small piece of fat is usually placed over the surface of the nerve to prevent adhesions.  More recently, a number of synthetic materials have been made available which provide this same function.  The tissues are then closed in three layers, the muscle fascia, the subcutaneous fat, and the skin.   Most frequently, the skin closed under its surface using a subcuticular suture.