Surgery For Disk Disease - When Surgery Is An Option: Back Pain

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Surgery for disk disease

More than 90% of people with herniated disks will recover within six weeks to several months without surgery by using conservative measures. But if you are among the other 10% — or if you simply don't have the time to wait — surgery may provide an option.

Several options exist for disk surgery, so it's important to work with your surgeon to determine which operation is best for you. One of the most common types of disk surgery performed is diskectomy, the removal of a portion of a damaged disk. Several types of diskectomies are available. With regard to all diskectomy procedures, however, bear in mind that although they provide better pain relief over a four-year period than nonsurgical treatments, it's not clear whether surgery is more of an advantage after 10 years. And studies of two particular types of procedures — percutaneous diskectomy and laser diskectomy — show that these techniques do not yet have the same success rate as standard diskectomy.

Standard diskectomy

A standard diskectomy involves making an opening in the spinal canal between adjacent laminae (the bony plates of each vertebra that join in the midline) and removing material protruding from the abnormal disk. Since the problem area is directly exposed during surgery, the risk of inadvertent damage to neighboring bone, ligaments, and nerve roots is minimized.

The surgeon will clear out any disk material that has become detached (known as free fragments). If the disk has not fragmented but a significant portion protrudes extensively into the spinal canal, compressing a nerve root, the surgeon will trim the bulging portion. He or she will also remove some portion of the soft part of the disk between the vertebrae.

Disk excision sometimes requires a laminectomy. In this procedure, the surgeon cuts out all or part of one or both laminae, so that he or she has better access to a herniated disk. The bulging portions of the disk are removed through this opening.

For standard diskectomy, you should expect a hospital stay of a couple of days, typically followed by a course of physical therapy at home. During the first six weeks or so following surgery, try not to sit for longer than 15–20 minutes at a time. When you do sit, recline your chair back about 30 degrees from vertical. Avoid bending, lifting, and twisting, but start walking as soon as you can tolerate it. Two weeks after the operation, you can begin stationary bicycling and swimming. If you develop back or leg pain, though, ease off and talk with your doctor. You can usually resume normal, nonvigorous activities six weeks following surgery, although you and your surgeon can speed up or slow down the schedule according to your individual situation.

Microdiskectomy. This is a type of standard diskectomy that involves a smaller incision. Its benefits include a shorter hospital stay and less risk of the postsurgical complications that can come with a longer hospitalization, such as postoperative blood clots. The procedure does have some drawbacks, but its success rate is similar to that of standard diskectomy.

Percutaneous diskectomy

This procedure involves the removal of a portion of a damaged disk through an instrument inserted in the back (see Figure 13). It is a less invasive technique than standard diskectomy. Before considering the procedure, try a minimum of six weeks of conservative, nonsurgical back therapy.

Figure 13: Minimally invasive types of disk surgery Minimally invasive techniques for disk surgery use different types of instruments, but all involve a similar approach into the herniated disk. In percutaneous diskectomy, a portion of a damaged disk is removed with a probe. In laser diskectomy, a small amount of disk material is vaporized with a microlaser. In chemonucleolysis, an enzyme (chymopapain) is injected to dissolve disk material.

In this procedure, the surgeon makes a tiny incision and inserts a hollow probe 2 millimeters (1/16 inch) in diameter. Visualizing the site by fluoroscopy, in which x-rays project a continuous image of the body's internal structures on a fluorescent screen, the surgeon guides the probe precisely through the skin, muscle sheath, and muscles to reach the affected disk. The surgeon then guides the probe into the center of the disk and uses an automated cutting-irrigating-suctioning tool, which is inserted through the probe, to remove some of the nucleus and annulus from the herniated disk.

This delicate operation can reduce both the pressure and volume of the material inside the disk, thus relieving the irritation of the nerve root. The incision is small, the procedure requires local anesthesia only, and you can usually return home on the same day or the next. For the next few weeks, you'll need to avoid sitting for longer than 15–20 minutes at a time, as well as bending, twisting, and lifting.

But this procedure also has substantial disadvantages compared with standard diskectomy. Since the compressed nerve root remains hidden from direct observation during the operation, the surgeon often cannot be sure that the pressure on it has been reduced or eliminated. Should a bit of the soft center of the disk slip out through the annulus, the surgeon has no way of finding and removing it. Such a free-floating piece of disk can cause pain. In addition, there is a small risk of infection, and of damage to nerves, organs, and blood vessels in the area.

Laser diskectomy. Laser diskectomy is a variation of percutaneous diskectomy (see Figure 13). In this procedure, rather than removing some of the disk material with a cutting-irrigating-suctioning tool, the surgeon uses a medical laser to vaporize part of the nucleus. The benefits, risks, and success rates associated with laser diskectomy are the same as those for percutaneous diskectomy.

Chemonucleolysis

Chemonucleolysis was introduced as a less invasive treatment for herniated disks in 1963, but it remains controversial. In this technique, an enzyme, chymopapain, is used to dissolve a portion of the herniated disk (see Figure 13). While you lie face down on a table, the surgeon uses x-rays to locate the affected disk and then injects chymopapain into it through a long needle. This causes a chemical reaction that breaks down the nucleus, releasing water.

The treatment is more popular in Europe than it is in the United States, and studies show that it is effective. A 2002 study published in Neurosurgery, involving 3,000 people who were treated with chemonucleolysis between 1984 and 1999, found that the success rate was 85%. A 2003 Irish study, in which researchers followed 112 herniated-disk patients for almost 10 years, concluded that chemonucleolysis was a safe and effective treatment for those with only one collapsed disk.

Chemonucleolysis is not for everyone. It's suitable for people who suffer from disk herniation characterized by leg pain, and who have a soft protruded disk rather than a diffuse bulging disk. Younger individuals who have not had their symptoms too long and who were able to raise their leg straight in front of them during an exam are considered the best candidates.

Although less invasive than diskectomy, chemonucleolysis can result in several days of severe pain and other unwanted — and occasionally serious — side effects. Risks include severe allergic reactions to the enzyme used in the procedure, ranging from a simple rash, itching, and localized swelling to anaphylactic shock, a life-threatening condition characterized by an extremely rapid, sharp drop in blood pressure. (The incidence of such reactions can be significantly reduced, although not eliminated, by the use of a simple skin test for an allergic reaction to the enzyme.) In addition, if chymopapain should come into contact with certain structures near the disk, it can cause serious neurological damage.

Intradiscal electrothermal annuloplasty (IDET)

Intradiscal electrothermal annuloplasty, which first became available in 1997, is an option for people who have certain kinds of disk problems, such as small herniations, internal disk tears, and mild disk degeneration. In this procedure, a surgeon inserts a hollow needle into the affected disk, threads a thin catheter through the needle, and positions the catheter along the inner wall of the disk. The catheter is then heated to approximately 150° F, which cauterizes the small nerve fibers in the disk wall in an effort to relieve pain.

Although generally regarded as a safe procedure, IDET is not particularly effective. A 2004 study published in Spine, for example, found that one year after the procedure, half of those treated were unhappy with the outcome of their therapy and 97% continued to have pain, with 29% saying they had more pain after IDET than before the procedure. And the percentage of people who were on disability was the same as before treatment.

Last updated:	January 23, 2007