What Is an Intradiscal Electrothermal Therapy procedure?

Intradiscal electrothermal therapy (IDET) treats low back (spinal disc) pain.

Intradiscal electrothermal therapy (IDET) or intradiscal electrothermal annuloplasty (IDEA), is a minimally invasive technique for the treatment of low back pain caused due to problems with the spinal disc. 

IDET introduces a flexible catheter into the disc under fluoroscopic guidance. The catheter is composed of a thermal coil heats the posterior part of the disc, causing contraction of collagen fibers and destruction of the pain receptors.

Studies have shown that 70% of patients with chronic low back pain benefit from IDET. Physical function and quality of life outcomes have improved in selected patients. IDET is minimally invasive and has a low complication rate.

As with other interventional procedures, proper patient selection increases the chances of a favorable outcome. IDET may be considered in patients who have had low back pain that does not radiate to the limbs for more than six months, without improvement from conservative treatment.

Ideal candidates are patients with a single affected disc. The status of the spinal disc can be assessed by X-ray and magnetic resonance imaging (MRI). Major spinal disc damage like disc collapse may not respond to IDET because it would also affect the accurate placement of the catheter during the procedure. 

Patients older than 55 years may have lower success rates because of poorer healing. Cigarette smoking may affect collagen tissue and delay recovery following the procedure.

The procedure is performed under local anesthesia. 

IDET is thought to decrease discogenic pain through two different mechanisms, as follows:

• Thermal modification of collagen fibers
• Destruction of disc nociceptors (a type of pain receptor present in various parts of the body that are stimulated by mechanical or physical damage like bruises, burns, fractures, and joint damage like arthritis and sprains)

Once the catheter is inserted and in a satisfactory position, it is heated from 98.6 to 167 °F. After the temperature has remained at 167 °F for one minute and the patient does not complain of excessive pain or discomfort, the temperature is increased by 1°F every 30 seconds it reaches between 176° to 194 °F. 

Breakage of heat-sensitive hydrogen bonds of the collagen fibers causes collagen contraction. The heat causes the destruction of disc nociceptors. 

The recovery after IDET is gradual. During the first week after the procedure, patients might experience a significant increase in pain. It may take 8-12 weeks for patients to experience significant pain relief. 

The healing process reaches its peak four months after the procedure. During the four months of recovery, the patient is advised to limit physical activity and follow a rehabilitation program. A gradual increase in daily activities is recommended. 

The patient should do only minimal sitting or standing during the first few days after the procedure. The patient would be advised to wear a back brace during the first six weeks. 

After six months of the IDET procedure, patients can gradually resume all pre-procedure activities, including athletics.

The typical progression of activities after IDET is given below.

Activities in week 1 are as follows:

• Walking allowed
• Wearing a brace during all activities
• Siting for only 35-45 minutes at a time
• No lifting, twisting, bending, or driving
• No work
• No physical therapy

Activities in weeks 2-6 are as follows:

• Wearing a brace during all activities
• Increasing sitting time as tolerated
• Lifting no more than 10 lbs.
• Driving is allowed
• No twisting or bending
• Patients may return to light or sedentary work
• No physical therapy

Activities in weeks 6-12 are as follows:

• Lifting no more than 25 lb
• No twisting or bending
• Physical therapy may begin

Activities beyond week 12 are as follows:

• Lifting 25-50 lb
• Patients may return to full work
• Physical therapy and home exercise program can begin