A New Treatment For Painful Disc Degeneration. The use of heat to treat various ailments is not new. Hippocratic use of a flaming brand to the shoulder would cure recurrent dislocations. More recently we have been applying modern “Flaming brands” via an arthroscope to the anterior capsule of the shoulder using radio–frequency probes.
The intervertebral disc presents a particular problem as it has high impedance and fails to allow sufficient energy to be delivered to raise the temperature of the discs to a therapeutic level. This problem has been overcome by a novel method of delivery of the thermal energy from a radio–frequency generator via a special intradiscal catheter–the Spine CATHTM.
A Big Problem
Over 60% of the adult population will suffer from significant back pain in their lives and 34% of these will have periods of absence from work because of back pain. The cost of back pain to the patient, in lost income, to society, in lost production, benefit payments and medical care and to the medical and allied professions who treat these patients is immense.
- 61% of all adults have back pain at some time in their lives.
- 34% will loose time of work because of back pain.
Provocative discography, spinal probes, diagnostic injections and MRI findings may suggest the site of the painful locus but have to be taken in context with the whole patient and are not a substitute for good history taking and examination.
Intradiscal Electrothermal Therapy
Intradiscal Electrothermal Therapy is a method of selectively heating the posterior annulus to 90 degrees centigrade to allow thermal destruction of nociceptors within the degenerate annulus, and to denature the protein of the posterior annulus in such a way that it undergoes a repair process.
The effect of heating the annulus–(Collagen and pain fibers) The lamella structure of the lumbar disc annulus undergoes a process of delamination and fissuring which begins after the nuclear hydrostatic pressure becomes reduced early in the degenerative process. The posterior annulus is principally affected due to high stress concentrations. A partial healing response occurs which leads to the ingrowths of granulation tissue and nerve fibers. The annular nociceptors, through either a direct mechanical stimulus or activation by inflammatory mediators, are becoming widely regarded as the prime contributor to discogenic pain. Collagen contraction occurs at a molecular level, with temperatures between 60 and 80 degrees centigrade breaking the hydrogen bonds supporting the triple helix structure of the collagen molecule. Although it reduces the tissue strength initially, this collagen modification stimulates a remodeling process that has demonstrated an increased collagen density and restored strength in longer–term histological and biomechanical research studies.
Research and clinical experience has long demonstrated that tissue temperatures above 42 degrees can thermo coagulate (permanently desensitize) unmyelinated nociceptive fibers. Previous experience with neuroablative procedures has shown that nerve regeneration can often occur, causing a return of symptoms. The objective of the Intradiscal Electrothermal Therapy procedure is to safely elevate the temperature over a broad area of the posterior annulus to the levels that thermo coagulate the annular nociceptors, and contract annular collagen thereby improving the structural integrity of the disc as a longer–term solution than neuroablation alone.