Intradiscal electrothermal treatment for chronic discogenic low back pain: a prospective outcome study with minimum 1‐year follow‐up. (SOAR, Physiatry Medical Group, Menlo Park, CA) Spine 2000;25:2622–2627.
Authors: Saal Jeffrey A. , Seal: Joel S. 
Published: March 2003

This prospective case series study was to determine the outcome of patients with chronic low back pain whose symptoms did not improve with aggressive nonoperative care and who chose intradiscal electrothermal anuloplasty (IDET) as an alternative to chronic pain management or interbody fusion surgery. Sixty‐two patients who had chronic low back pain unresponsive to nonoperative care, no evidence of compressive radiculopathy, and concordant pain reproduction at one or more disc levels on provocative discography were enrolled in the study. Visual analog scale (VAS) pain scores Short Form (SF)‐36 Health Status Questionnaire Physical Function subscale, and SF‐36 Bodily Pain subscale scores were assessed at baseline and at least 1 year later. Mean follow‐up was 16 months, and mean preoperative duration of symptoms was 60 months. Baseline and follow‐up outcome measures demonstrated a mean change in VAS score of 3.0, mean change in SF‐36 physical function of 20, and mean change in SF bodily function of 17. Symptoms improved in 44 (71%) of 62 of the study group on the SF‐36 physical function subscale, in 46 (74%) of 62 on the SF‐36 Bodily Pain subscale, and in 44 (71%) of 62 on the VAS scores. Twelve (19%) of 62 did not show improvement on any scale. Conclude a cohort of patients with chronic unremitting low back pain of discogenic origin whose symptoms had failed to improve with aggressive nonoperative care demonstrated a statistically significant and clinically meaningful improvement on the SF‐36 and the VAS scores at a minimum follow‐up of 1 year after IDET. The positive results should be validated with placebo‐controlled randomized trials and studies that compare IDET with alternative treatments.

Comment by Gabor B. Racz, M.D. This is a report on 62 patients from a single practice where the diagnosis of discogenic pain was made. Prior to and at the end of 12‐months, visual analog pain scores and short form (SF‐36 Health Status Questionnaire Physical Function subscale and SF‐36 Bodily Pain subscale scores were assessed. The results indicate a VAS score reduction of 3.0 and a change in SF‐36 physical function of 20 and mean change in SF‐36 bodily pain of 17. Nineteen percent of the 62 patients did not show improvement on any scale.

There are significant problems with this study in that there are no controls and no randomization, no reasonable alternatives to heat lesioning the disc was offered as the patient was given the only alternative of interbody fusion surgery. The materials and methods describe the practice as 1,116 patients with chronic low back pain referred to the authors. This must be an unbelievably unique practice as anybody that works with chronic patients would find it almost impossible to have patients with chronic low back pain with no leg pain. It is the rule rather than the exception that patients come to us with back and leg pain. Discogenic pain can give rise to back spasm. The pathways for discogenic stimulation leading to paraspinal spasm have been beautifully outlined by Indahl. Injury to the disc can lead to leaking of disc material causing epidural scar formation involving the sinovertebral system nerves and nerve root or nerve roots. Simultaneously, there may be facet involvement and back spasm originating from the same process. The pathway for discogenic back spasm as suggested by Indahl is likely from the lateral branch of the posterior primary ramus and can also be interrupted by diagnostic nerve block followed by radiofrequency thermocoagulation.

The patients in this study supposedly have failed all therapeutic modalities, yet, there is absolutely no mention of caudal lysis of adhesions or transforaminal lysis of adhesions and/or diagnostic and radiofrequency thermocoagulation of the pathways for discogenic back spasm. In our clinical experience, it is extremely rare where patients described in this series would have exclusive solitary disc problem necessitating electro‐thermo‐lesioning of the disc. We certainly find that a great deal of the problem is located in the spinal canal rather than exclusively in the disc or facets. Freeing up the ventral and lateral epidural space by the lysis of adhesions technique, followed by addressing the sino vertebral nerve and facet joint innervation can lead to excellent pain relief for 5 years or longer when the problem is looked at in a nonrandomized, noncontrolled study environment. Furthermore, the pain relief is prompt and does not necessitate the rather elaborate precautions outlined in this paper that clearly are different than the conservative therapy offered to these patients prior to disc lesioning. In the very rare instance, where clearly there is no spinal canal pathology and there is no facet and discogenic back spasm, we do believe an appropriately carried out discogram with monitoring of facial expressions and pressure recordings had resulted in clear rapid response pain relief. I just find a great deal of difficulty in understanding the physiological process of burning the structures within the disc that can take months to lead to pain relief. The rational expectation is that if you thermocoagulate a nerve that is involved in propagating pain, that you should have prompt and lasting pain relief until those nerves or pain pathways regenerate. Clearly, one needs to clarify the issues involved in exposing patients to discitis and osteomyelitis by interventional lesioning with no clear‐cut evidence of reasonable results. The studies need to be carried out with appropriate controls and randomization.

Our clinical experience with intradiscal electrothermal treatment comes from two sources. One source is patients who have had the treatment elsewhere and failed to respond and the second source is where we have ruled out any other explanation for the patient's back pain and the patient responds to diagnostic and therapeutic disc procedures, but more commonly without a favorable outcome. These patients then are offered the option of various neuromodulation pain relieving procedures rather than interbody fusion surgery. Richard North has rather convincingly shown documented evidence that spinal cord stimulation gives better outcome than back surgery.