Intradiscal electrothermic therapy (IDET) for low back pain

Surgery Overview

Intradiscal electrothermic therapy (IDET) is a relatively new, minimally invasive treatment for spinal disc-related chronic low back pain. This type of persistent disc pain is thought to be caused by nerve fibres that have grown from their normal location in the outer layers of the disc, reaching into the disc interior.¹ This is related to the breakdown (degeneration) of the tough outer layers (annulus) of the disc. The pain may also be from injury to the disc, causing the material in the centre (nucleus) of the disc to move into the outer layers of the disc. This material from the nucleus is irritating to the outer layers, where the nerves are, and causes pain.

Discography is generally done before IDET to try to clearly identify the disc problem. After discography, your doctor will decide whether it is likely that your disc problem can be helped by IDET. Before an IDET procedure, you are given a sedative and a local anesthetic. Using "live" X-ray imaging (fluoroscopy), a doctor inserts a hollow needle containing a flexible tube (catheter) and heating element into the spinal disc. The catheter is positioned in a circle in the outer layer (annulus) of the disc and is then slowly heated to about 90°C (194°F) . The heat is meant to destroy the nerve fibres and toughen the disc tissue, sealing any small tears. Antibiotics, either given in a vein (intravenous) or injected into the disc, are used to prevent a disc infection.

See a picture of intradiscal electrothermic therapy.

What To Expect After Surgery

Pain relief after intradiscal electrothermic therapy (IDET) is not immediate. Pain may increase during the first couple of days. Physical therapy is a necessary part of recovery. During the first month after IDET, plan to walk and do easy stretches as prescribed by your doctor. During the first 2 to 3 months, exercise as directed, and avoid lifting, bending, and long periods of sitting.

People who have had IDET are usually told to wait at least 5 to 6 months before resuming strenuous sports such as skiing, running, or tennis.²

Why It Is Done

Intradiscal electrothermic therapy (IDET) is used to treat a select subgroup of people who have had chronic disc-related low back pain (usually for at least 3 to 6 months) despite non-surgical treatment.^{3, 4} IDET is not recommended for people with severe disc degeneration, spinal stenosis, or spinal instability (such as spondylolisthesis).

How Well It Works

Since its introduction in the 1990s, intradiscal electrothermic therapy (IDET) has been evaluated in several small studies. Larger studies have been hard to do, because most people do not meet the requirements for this procedure. Some research has suggested IDET is a safe and effective intermediate treatment for people who fit the criteria for the procedure.⁴ Other studies have not shown IDET to be any better than a placebo for easing back pain.^{3, 5} When two good studies such as these do not have the same results, it means further research would be helpful. More research on IDET will show the effectiveness of this procedure more clearly.

Risks

Complications of intradiscal electrothermic therapy (IDET) are relatively uncommon. In one study of 58 people, no complications were observed.² Another study of 33 people reported 5 (15%) cases of increased nerve root pain after IDET that were successfully treated with epidural corticosteroid injection.¹

Although complications are rare, possible risks include:

• Nerve damage.
• Disc damage.
• Disc infection.

What To Think About

If you are considering IDET, be sure that you are a good candidate for the procedure and that the doctor performing the procedure is well trained and experienced. If you are unsure about whether IDET is right for you, consider getting a second opinion.

Here are some of the criteria used in studies to decide who might be a good candidate for IDET.^{3, 4}

You may be a candidate for IDET if:

You are probably not a candidate for IDET if:

You are at least 18 years old. You have had disc-related pain for several months. Some studies require pain to have been present for at least 3 months, but many require 6 months. Your symptoms have not improved with at least 6 weeks of non-surgical treatment, including pain medication and physiotherapy or a home exercise program for low back pain. Pain is mostly in the low back, not in the leg. Pain is worst when you are sitting. The damage is at the back of the outer layer (annulus) of the degenerated spinal disc.

You do not meet all the criteria to be eligible for IDET (such as the criteria listed in the column to the left). You have severe disc degeneration. If the degeneration is too great, there is not enough room to insert the needle for the IDET procedure. You have spinal stenosis. You have a spondylolisthesis. You have another medical condition that could increase the risk of surgery or make follow-up care difficult.

Your health insurance provider may not cover this procedure.

Complete the surgery information form (PDF)(What is a PDF document?) to help you prepare for this surgery.

Author:	Shannon Erstad, MBA/MPH Ralph Poore	Last Updated: March 31, 2008
Medical Review:	William M. Green, MD - Emergency Medicine Robert B. Keller, MD - Orthopedics Andrew Swan, MD, CCFP, FCFP - Family Medicine
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