Intradiscal electrothermal annuloplasty: Percutaneous treatment of chronic discogenic low back pain

Therapeutic effect of intradiscal pulsed radiofrequency on internal disc disruption: A case report

RATIONALE

Discogenic low back pain often persists despite medication and medical intervention. In this study, intradiscal pulsed radiofrequency (PRF) was performed in a patient with discogenic low back pain who did not respond to oral medication, posterior medial branch block, epidural steroid injection, and percutaneous epidural adhesiolysis.

PATIENT CONCERNS

A 28-year-old woman visited a pain clinic complaining of low back pain that was scored 8 out of 10 on a numerical rating scale. Her pain was present in any position throughout the day and worsened in the sitting position.

DIAGNOSES

Magnetic resonance imaging showed L5-S1 internal discal disruption. Based on the medical history, physical examination, and magnetic resonance imaging, we determined that her pain originated from the L5-S1 disc.

INTERVENTIONS

We performed an intradiscal PRF on the affected disc under C-arm fluoroscopy guidance. PRF was performed at 5 Hz, 20-ms pulse width, and 70 V for 15 minutes while ensuring that the electrode tip temperature was maintained below 42°C.

OUTCOMES

Immediately after the procedure, the patient's pain subsided. At the 1-month follow-up visit, the patient reported complete relief of her low back pain. The Oswestry disability index, which indicates the degree of disability, improved significantly. She also reported that she could sit for long periods because the pain was reduced. No adverse effects from the procedure were found.

LESSONS

Applying intradiscal PRF seems an effective and safe technique for treating discogenic low back pain.

Histological and molecular structure characterization of annular collagen after intradiskal electrothermal annuloplasty

The mechanism of pain relief of intradiskal electrothermal annuloplasty (IDET) in the treatment of lumbar diskogenic pain is uncertain. Theories include sealing of annular fissures via collagen denaturation and contraction. Prior studies offer conflicting qualitative data on the ability of IDET to denature collagen. The objective of the present study is to evaluate IDET treatment effect on annular collagen using quantitative data supplied by Fourier-transform infrared imaging spectroscopy. The posterior annulus of disks (n = 3) from an intact human cadaveric spine at room temperature were treated with two different radiothermal catheters using standard intradiskal electrothermal annuloplasty (IDET) heating protocols. Disks were dissected free with catheters in place and fixed in formalin. Channels created by the catheters were marked and catheters were removed. Tissue samples of treated areas adjacent to the channels and internal control areas from the same disk were stained for light microscopy and placed on barium sulfate windows for Fourier transform infrared imaging spectroscopy (FT-IRIS) analysis. Treated areas showed evidence of disruption in the fibrillar organization of annular collagen by light microscopy compared to intact stroma from control areas. Quantitative FT-IRIS analysis compared ratios of wavenumber regions known to be sensitive to collagen denaturation. Mean values for the ratios amide II/1,338 cm(-1) (137.21 +/- 25.84 treated, 76.94 +/- 16.77 control) and 1,640/1,660 cm(-1) (0.98 +/- 0.03 treated, 0.89 +/- 0.03 control) were significantly different between treated and control samples (p < 0.001), indicating a breakdown in collagen integrity. Separate analysis by catheter type suggests that catheter design may impact treatment effect.

A randomized, placebo-controlled trial of intradiscal electrothermal therapy for the treatment of discogenic low back pain

BACKGROUND

Intradiscal electrothermal therapy (IDET) is a treatment for discogenic low back pain the efficacy of which has not been rigorously tested.

PURPOSE

To compare the efficacy of IDET with that of a placebo treatment.

STUDY DESIGN/SETTING

Randomized, placebo-controlled, prospective trial.

PATIENT SAMPLE

Patients were recruited by referral and the media. No inducements were provided to any patient in order to have them participate. Of 1,360 individuals who were prepared to submit to randomization, 260 were found potentially eligible after clinical examination and 64 became eligible after discography. All had discogenic low back pain lasting longer than 6 months, with no comorbidity. Thirty-seven were allocated to IDET and 27 to sham treatment. Both groups were satisfactorily matched for demographic and clinical features.

METHODS

IDET was performed using a standard protocol, in which the posterior annulus of the painful disc was heated to 90 C. Sham therapy consisted of introducing a needle onto the disc and exposing the patient to the same visual and auditory environment as for a real procedure. Thirty-two (85%) of the patients randomized to the IDET group and 24 (89%) of those assigned to the sham group complied fully with the protocol of the study, and complete follow-up data are available for all of these patients.

OUTCOME MEASURES

The principal outcome measures were pain and disability, assessed using a visual analog scale for pain, the Short Form (SF)-36, and the Oswestry disability scale.

RESULTS

Patients in both groups exhibited improvements, but mean improvements in pain, disability and depression were significantly greater in the group treated with IDET. More patients deteriorated when subjected to sham treatment, whereas a greater proportion showed improvements in pain when treated with IDET. The number needed to treat, to achieve 75% relief of pain, was five. Whereas approximately 40% of the patients achieved greater than 50% relief of their pain, approximately 50% of the patients experienced no appreciable benefit.

CONCLUSIONS

Nonspecific factors associated with the procedure account for a proportion of the apparent efficacy of IDET, but its efficacy cannot be attributed wholly to a placebo effect. The results of this trial cannot be generalized to patients who do not fit the strict inclusion criteria of this study, but IDET appears to provide worthwhile relief in a small proportion of strictly defined patients undergoing this treatment for intractable low back pain.

Radiofrequency procedures in chronic pain

Radiofrequency current is simply a tool used for creating discrete thermal lesions in neural pathways in order to interrupt transmission. In pain medicine, radiofrequency lesions have been used to interrupt nociceptive pathways at various sites. This is a palliative treatment not without complications, so its use should be limited to those patients with cancer pain or chronic non-cancer pain for whom conservative non-surgical therapies have been ineffective or intolerable. With the development of alternatives such as intrathecal opioid infusion and neuromodulation technologies, the number of patients considered for neuroablative therapy may dwindle. Nevertheless, there is evidence that radiofrequency neurotomy has an important role in the management of trigeminal neuralgia, nerve root avulsion and spinal pain. In this chapter the evidence for efficacy and safety is reviewed and interrogated with special emphasis on the available randomized controlled trails and systematic review.

Two-year follow-up of a controlled trial of intradiscal electrothermal anuloplasty for chronic low back pain resulting from internal disc disruption

BACKGROUND

On the basis of observational data, intradiscal electrothermal anuloplasty (IDETA) has been implemented as a treatment for back pain resulting from internal disc disruption.

PURPOSE

To assess the efficacy of IDETA.

STUDY DESIGN

Prospective cohort study with comparison group and 2-year follow-up.

PATIENT SAMPLE

Of 53 patients who satisfied the diagnostic criteria for internal disc disruption, 36 were allocated to a treatment group and 17 to a comparison group, according to whether their insurer approved treatment with IDETA.

OUTCOME MEASURES

Outcomes were assessed in terms of relief of pain, return to work and use of opioids to treat persisting pain.

METHODS

The treatment group underwent IDETA. The comparison group underwent a conventional rehabilitation program. Outcomes were assessed at 3 months, 12 months and 2 years after treatment.

RESULTS

As a group, the comparison patients exhibited no significant improvement in their pain at any time. One was partially relieved, but no patient was completely relieved at either 12 or 24 months. The patients treated with IDETA exhibited significant improvements in their median pain scores, which were sustained at 12 and 24 months. At 24 months, 54% of these patients had achieved at least 50% relief of their pain, no longer used opioids and were at work. Seven patients (20%) were totally free of pain and at work at 24 months.

CONCLUSIONS

The long-term results of IDETA are stable and enduring. It is not universally successful, but 54% of patients can reduce their pain by half, and one in five patients can expect to achieve complete relief of their pain.