IDET (Intradiscal Electrothermal Therapy)
 
  Practically everyone suffers from back pain at some point. Sometimes the pain results from pressure on nerves, sometimes from spinal fractures, and sometimes from problems with the cushioning discs that separate the bones of the spine. Depending on the cause of the pain, treatment can be as simple as rest and exercise, or as complex as major surgery. Usually, simpler methods are tried first; if they are not successful in relieving the pain, more aggressive treatments can be used.

A relatively new treatment for back pain resulting from problems within the cushioning discs is intradiscal electrothermal annuloplasty, also called intradiscal electrothermal therapy (IDET). This outpatient procedure applies high heat directly to the inside of the disc. It is a less expensive and less invasive procedure than spinal surgery, but it is not appropriate for everyone who has low back pain.

Disc anatomy

Discs are cushioning tissues located between each vertebra of the spine. The disc has a soft center (nucleus) surrounded by tougher ligament tissue (annulus). As we age, the outer ligament tissue begins to fray and tear from use or injury. This allows nerves and small blood vessels from the soft center to seep into the injury site, triggering pain receptors in the ligament tissue. The result is discogenic back pain.

Discogenic pain differs from a ruptured or herniated disc because the pain originates within the disc and does not come from nerves or other structures. Discogenic pain is confined to the back and does not radiate down the legs.

Diagnosis

In addition to interviewing you about the pain, the physician will take your medical history and give you a physical examination. Tests that can help determine the source of the pain include X-rays, magnetic resonance imaging (MRI), computed tomography (CT) scans and discography.

Discography is used to identify the painful disc. In this test, the physician pierces the disc with a thin needle and injects a contrast dye. X-rays show whether the dye enters the disc's outer tissues. Discography is called a provocative test because it will provoke pain in an injured disc.

IDET

IDET is usually reserved only for patients who have tried aggressive, non-operative techniques to relieve their pain without success. Because this is a relatively new procedure, you should make sure that the practitioner you see is adequately trained in using the equipment. The procedure itself takes about one hour to complete. A local anesthetic and intravenous pain relievers are used.

  • The physician uses an X-ray machine (fluoroscope) to see the spinal structures.

  • A hollow needle is inserted into the painful disc. A thin heating wire (electrothermal catheter) is passed through the needle into the disc, and maneuvered into place around the outer edge of the central nucleus.

  • The wire is heated slowly to a temperature of about 194 degrees Fahrenheit (90 degrees Celsius) for about 15 minutes. Heat can potentially contract and shrink the fibers that make up the disc wall, closing any tears. The heat can also potentially cauterize (burn) tiny nerve endings in the disc, making them less sensitive to pain.

  • After the wire and needle are removed, there is a short observation period before the patient is released.

Postoperative treatment

Although IDET is much less invasive than most back surgeries, it will still take several weeks for healing to occur. Pain relief is not immediate; pain may actually increase for a day or two after surgery. But gradually the pain from the procedure itself should diminish.

After the IDET procedure, you will need to rest for a few days and limit the time you spend sitting. You may need to wear a back support for several weeks. You will also need to participate in a physical therapy program. If your job is sedentary does not involve lifting or manual labor, you may be able to return to work in a week or so; otherwise it may be several months before you can resume your activities. You will not be able to participate in rigorous recreational activity or do any heavy lifting or twisting for at least six months after the procedure.

IDET is not recommended if you have severe disc degeneration, nerve compression, spinal instability and/or narrowing of the spinal column (spinal stenosis). IDET is not yet covered by many insurance plans.

The long-term results of this procedure are still unknown. IDET was introduced in 1997 and case series without controls have reported encouraging results. However, these results need to be confirmed in prospective, randomized trials. Additionally, there is debate about how the procedure actually works. Not every patient will benefit from IDET treatment. Some patients continue to experience back pain and may eventually have other surgical procedures.