The IDET procedure is usually done with a SpineCATH catheter, which is inserted into the nucleus pulposus compartment via a posterolateral approach into the disk with an appropriate catheter through which an electrothermal device is threaded and allowed to go anteriorly within the wall of the nucleus pulposus and then posteriorly to overly the entire posterior wall of the annulus. The device is then heated instrumentally to achieve 90 degrees Centigrade over a 12 minute and 30 second period and then sustained at 90 degrees for an additional four minutes, totaling 16 minutes and 30 seconds of controlled heating of the annulus and the surrounding nucleus pulposus.
The goal of this treatment has been generally accepted as that of hitting the collagen of the disk wall and raising the temperature of the nerve endings in order to achieve desensitization of the nerve endings, while the hit will alter the collagen protein to produce contraction and closure of disk wall fissures that were previously identified through a discogram. It has also been thought that there may be a possible reduction in the disk bulge in the affected disk level that may also result in pain relief.
The exact method of achieving pain relief has not been conclusively scientifically determined, but this procedure has been known to be highly effective in treating patients who meet the criteria. It is also important to note that this procedure can only be done on patients who, with a flexion and extension view of the lumbar spine, demonstrate stability without a worsening spondylolisthesis on lateral view of the spine. The IDET procedure in such selected patients has replaced the traditional anterior posterior lumbar fusion with grafting and instrumentation for treatment of discogenic low back pain, thereby significantly minimizing morbidity, short term and long term, as well as the incidence of complications and likelihood of ultimate disability from complications related to lumbar spine fusion.
INDICATIONS FOR IDET
The primary indications for the IDET procedure are as described above.
The risks associated with IDET include discitis, temporary nerve root irritation as a result of the close proximity of the heat and the annular wall to adjacent nerve roots or because of mechanical trauma of the tip of the needle in the attempt to access the nucleus pulposus of the patient undergoing IDET.
The IDET procedure should not be done in patients who have anticoagulation abnormalities, including being on Coumadin or Heparin. Coumadin should be stopped at least three days before the procedure to ensure the return to normalcy in most patients. Pregnant patients, or patients who may suspect they may be pregnant, should also not undergo IDET procedure
Because the patient might undergo light general anesthesia, the patient should only take light, clear liquids until 12 hours prior to the procedure being done. They should be NPO (none per oral) before the morning of the procedure. The IDET procedure is usually a safe and uneventful procedure.
Following the IDET procedure, which is a procedure done on an outpatient basis and monitored under anesthesia care or light general anesthesia, the patient is allowed to wear a lumbar brace for six weeks during which there is gradual instrumental increase in activity and mobility with bed rest and restriction with lifting of any type or prolonged walking or travel imposed on the patient for the first one to two weeks, at least. This is because the disk that has undergone thermal heating is unstable and, with additional trauma, could result in further soft tissue injury or even worsened herniation. The reorganization of the tissue of the disk is allowed to take place by protocol over a four to six-week period before starting a protocol of physical therapy with graduated exercise and challenge. The effect of IDET procedure is not immediate and IDET should be allowed a period of six weeks to five months post procedure before a true evaluation of its success or failure can be made; it may take that long for the altered disk material to reorganize.