The IDET procedure has recently emerged as a procedure which brings hope to many patients with discogenic back pain. This pain may be caused by internal disc derangement or annular tear of the discs.
Before describing the procedure an understanding of the disease process is necessary. There are several reasons forsensation of the pain perceived from discs in the spine. These include annular tears, internal disc derangement, bulging of the intervertebral disc, and unknown etiologies. As we age, there is a natural degenerative process that takes place in our bodies. These changes are as natural as the wrinkles that occur on our faces. Most patients remain pain free even with these degenerative changes in their spine. However, a small subset of the population will develop degenerative disc disease that will cause sever pain leading to dysfunction. The disc has two main components which includes the nucleus polposus and the outer annulus. The nucleus is normally well organized almost gelatinous in consistency and is contained within a thick outer covering which is referred to as the annulus. Many nerve endings reside within the annulus and so this structure is very sensitive to pain. As the water content of our body changes, the structural integrity of the annulus decreases. This leads to cracks, fissures, and tears within the annulus and may stimulate the nerve endings in that area. Once the tear occurs in the annulus, the problem may stay static, improve, or worsen. The annular tear may produce pain or lead to the herniation of the nucleus polposus. The diagnosis of these disease processes are challenging and may require specialized diagnostic studies. These may include MRI scans, myelograms, or Discograms combined with a CT scan. These studies are then evaluated by your spine surgeon to arrive at a logical explanation to the patients’ pain. This requires sound clinical judgment, knowledge, and experience.
Traditionally non-operative treatments have been offered to patients with annular tears and discogenic pain. Once non-operative treatments failed, the alternative surgical treatments would be offered. Prior to the IDET procedure, fusion of the spinal segment would be performed after removal of the offending disc. The downfall is the surgical risk and the relatively large operation needed. Furthermore, successful outcome was not always achieved with reported success rates of around 65%. With more recent implants and techniques we now achieve higher rates of success closer to 75-80%.
In an attempt to avoid such surgery the company by the name of Oratec introduced the SpineCATHTM to perform Intra-Discal Electro-Thermal Therapy. This is a minimally invasive procedure that attempts to avoid more extensive spinal operation such as a fusion. After the insertion of a small catheter into the disc space, controlled and specific amounts of heat are applied in the hope that the annulus will close up. Theoretically, the nerves that produce pain are also destroyed decreasing the perceived pain from that area. Some surgeons also report reduction in the size of the disc bulge but this is controversial.
Patients usually arrive at the surgical center and kept lying down on their abdomen. Sedatives are injected to keep the patient comfortable. This procedure is performed under strict sterile conditions to avoid infection of the disc space. Fluoroscopy imaging is used to provide us with precise access to the painful disc space. A larger needle is then inserted in the anesthetized section of the skin and advanced into the disc space. Once in the disc space, a long wire which carries with it the heating coil is inserted into the needle and advanced into the disc. It is then connected to the machine and controlled heat is applied to the disc space. Each disc will require 15 minutes to complete. This procedure may reproduce the patient’s pain and provide us with yet another indication of the offending disc space. Pain medications are then provided to keep the patient comfortable until the end of procedure. Band-Aid is applied and the patient is discharged home shortly after completion of the procedure.
Cross sectional view of the needle being inserted into the disc space
Following the procedure, it is important to know that the pain may actually increase compared to the pain that existed prior to the procedure. However, discouragement should not set in since this is expected after insertion of instruments such as needles within the disc space. Usually the pain will improve after one week and the healing process will only begin at that time. If needed, your physician may prescribe pain medication for the first week and help the patient during this time. The patient should keep a diary of the degree of pain to keep track of progress or failure to do progress. Improvement in pain may continue up to six months.
The IDET procedure is a relatively new procedure introduced to the spine surgeon and his/her patients. Reported results in the literature are somewhat confusing and at times conflicting. However, the general consensus is that it may help a selected group of patients. About 25% of patients with disc pain will greatly benefit from this procedure and about 50% of patients will decrease pain levels by half. Even though these statistics may not look favorable, upon re-examination, this may be attractive to the patient that is facing a fusion operation. If the IDET procedure succeeds, a fusion operation is avoided, and if it fails the patient still can undergo the fusion operation at a later time. Still, IDET has associated risk like infection, bleeding, and nerve damage. This risk is low but still possible. Discuss the issue with your spine surgeon to see if IDET is right for you. Call one of our offices to set up an appointment for evaluation.