Typically, the procedure involves the following steps (under local anaesthetic):
- a hollow needle is inserted into the wall of the painful disc;
- an electrothermal catheter (or heating wire) is passed through the needle and positioned near the herniation;
- the tip of the wire is then heated to 90°C for up to 15 minutes;
- the heat causes the wall of the disc to thicken, and burns the nerve endings around the tip of the wire;
- the catheter is then removed, along with the needle;
- a lumbar support is worn for up to eight weeks following the procedure;
- a course of physical therapy is then recommended;
- lifting and bending should be restricted during this time.
There are a number of conditions that preclude the use of IDET, usually because they are made worse by the procedure. The medical term for these is contra-indications.
The contra-indications for IDET include:
- severe disc degeneration;
- spinal stenosis;
- neurological symptoms (e.g. weakness in the leg);
- large disc herniations;
- short leg syndrome.