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PERCUTANEOUS ENDOSCOPIC ASSISTED MICRODISCECTOMY
This approach is also done as an outpatient. Endoscopic surgery is an exciting field. It is a microdiscectomy with even a more minimally invasive approach. With an endoscopic approach the patient has no hospital stay, no general anesthesia and allows the patient to possibly recover quicker. This procedure removes the herniated disk under direct vision, shrinks the remaining disk and destroys the in growth of abnormal pain fibers.
This procedure allows the patient to return to normal activity sooner. Like all of the treatments for back disease, the disk does not return to the healthy young non-diseased state. Instead, discectomy compares to removing a splinter. Not only is the mass removed, the inflammation is allowed to subside. Awake endoscopic microdiscectomy has revealed new information about the cause of pain in disk disease. During the procedure pain reproduction may be with stimulation of the annulus or nucleus propulsus. The location of the pain has been seen in the back, inguinal area and other non-dermaltomal areas. This information is new and must be studied in detail. Microdiscectomy surgery should mostly be performed for leg pain, paresthesia (tingling or numbness) or paresis (weakness). Even though surgery is performed, not all of the pain may resolve. Sometimes not all of the disk is removed.
MICRODISCECTOMY
Has been the mainstay of disk disease surgery. In 1934 Mixter and Barr published a description of disc herniation as the cause of leg pain. The surgery has evolved from a large operation with prolonged hospitalization to a microsurgical operation with patients able to be discharged on the day of surgery with complete resolution of their preoperative lower extremity pain. The history and physical must match the surgical pathology seen on MRI. Conservative therapy when appropriate, must fail to achieve its desired results. Vague symptoms can be delineated with selective, diagnostic and therapeutic nerve root blocks. At the beginning of the 21st Century, the neurosurgeons have to perform the best operation with the best outcome and at the lowest cost. Recently a microscopic discectomy system was introduced in which through successively larger dilators, the operation takes place endoscopically through a 14 mm. tubular retractor. It is possible without endoscopy, using only microneurosurgical principles, to perform outpatient lumbar microdiscectomy with possible complete resolution of preoperative radicular pain. The patient undergoes general endotracheal anesthesia, is placed prone on the operating table. The intended incision is fluoroscopically identified injected with xylocaine 0.5% with epinephrine 1:200,000, prepped and draped. The one level microdiscectomy incision is usually 14-18 mm in length (longer in more robust individuals). The skin is incised with a scalpel and carried down through the lumbar dorsal fascia including a subperiosteal dissection directly along the spinous process and lamina to the facets, with a monopolar cautery, and an instrument placed in the intralaminar space so that fluoroscopic x-ray could once again localize the correct disc space. The high-speed drill is used for a small lateral laminectomy. This includes 2 to 3 mm. of the inferior lamina from above, up to one-third of the medial facet and 2 to 3 mm. of the superior lamina from below. At L5-S1 more of the inferior lamina is taken with less of the superior lamina, and at L4-5 and above, more of the superior lamina is taken with less of the inferior. The nerve root is unroofed.
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