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Surgery for lumbar laminectomy is performed with the patient lying on his abdomen or side. A small incision is made in the lower back (Fig. 3).
After a retractor is used to pull aside fat and muscle, the lamina is exposed. Part of it is cut away to uncover the ligamentum flavum – a ligament that supports the spinal column (Fig. 4).
Entering the Spinal Canal
Next an opening is cut in the ligamentum flavum through which the spinal canal is reached. The compressed nerve is now seen, as is the cauda equina (bundle of nerve fibers) to which it is attached. The cause of compression may now also be identified – a bulging, ruptured or herniated disc, or perhaps a bone spur (Fig. 5).
Sometimes a fragment of disc has moved away from the disc space to press on the nerve root as it leaves the spinal canal (Fig. 6). This will often cause more severe symptoms. Because of its distance from the disc space, the fragment may not be seen on a myelogram, and a CT scan (computerized x-ray) may be required to locate it.
Removal of the Herniated Disk
The compressed nerve is gently retracted to one side, and the herniated disc is removed. As much of the disc is taken out as is necessary to take pressure off the nerve (Fig. 7). Some surgeons will remove all “safely available” disc material. After the cause of compression is removed, the nerve can begin to heal. The space left after removal of the disc should gradually fill with connective tissue.
Fusion and Instrumentation
The operation is completed when the incision is closed in several layers (Fig. 8). Unless absorbable suture material is used, the skin sutures (stitches) will have to be removed after the incision has healed.
Certain risks must be considered with any surgery. Although every precaution will be taken to avoid complications, among the most common risks possible with surgery are: infection, excessive bleeding (hemorrhage), and an adverse reaction to anesthesia. Since lumbar laminectomy involves the nervous system, nerve damage is another possible risk.
Clinical experience and scientific calculation indicate that these risks are low; but surgery is a human effort. Unforeseen circumstances can complicate a normally no-risk procedure and lead to serious or even life-threatening situations. Although such complications are rare, you should feel free to discuss the question of risk with your doctor.