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Three Part Question

[In patients with chronic back pain and discogenic pain as shown on CT discography] is [intradiscal electrothermal annuloplasty better than standard care] at [improving pain, global outcome score and returning patients to work]

Clinical Scenario

A 42 year man presents with a history of chronic back pain that has not resolved with good primary care management and active rehabilitation. MR and CT of the lumbar spine reveals a significant internal discdisruption at the L4/5 disc.You discuss surgical options of fusion but the evidence is not in favour. Reluctantly you suggest that conservative management is his best option. He returns 2 weeks later with information from the Internet on intradiscal electrothermal annuloplasty. The technique involves coiling a wire within the disc and then heating it to high temperature to seal any annular disruption. You wonder if this is another fad treatment or whether there is some evidence to support it's use.

Search Strategy

Medline 1966- June 2005 OVID via ATHENS
Medline
[intradiscal electrothermal.mp or IDET.mp or intradiscal adj5 electro$.mp] and [Limit to human and english and "therapy (sensitivity)"]

Search Outcome

Medline
38 papers found of which 2 were controlled trials. One trial was reported twice (at one year and at 2 years - only 2 year data given below.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Pauza KJ et al 2004 USA	64 patients with discogenic low back pain of more than 6 months duration. 37 had IDET, 27 had sham therapy (same procedure, needle placed in disc but IDET not performed. Discogenic pain diagnosed on provocation discography.	Prospective double blind randomised controlled trial	Patient flow through study	32/37 randomised to IDET and 24/27 randomised to sham therapy `finished the study. Patients breaking protocol were excluded suggesting the analysis is not intention to treat.	Patients were unblinded at 6 months, as the treatment is thought to be stable by then. Patients recreuited through advertisment. Trial was closed early owing to a difficulty in patient recruitment
			Change in pain score on 10 point VAS at 6 months	2.4 for IDET vs 1.1 for sham p=0.045
			Change in Bodily function on SF 36 at 6 months	17 for IDET vs 9 for sham p=0.086
			Change in physical function on SF 36 at 6 months	15 for IDET vs 11 for sham p=0.548
			Change in Oswestry disability scale at 6 months	11 for IDET for 4 sham p=0.050
			Categorical analysis of pain scores on 4 point scale (worse, same, small improvement, large improvement)	Favours IDET (p=0.37) but largely due to several people in the sham group deteriorating
			Sub group analyses	They found that patients with initial pain scores less than 70, with less function or greater disability at baseline did better, though these are very small numbers to draw subgroup analyses from.
Bogduk N 2002 USA	53 patients with discogenic back pain. Diagnosis confirmed with discography. 36 had IDET, compared against 17 with the same problem but who were denied treatment with IDET by their insurer. The control group had a structured rehabilitation program.	Prospective clinical trial	Pain scores on 10 point VAS at 3 months (no drop outs)	8 for standard therapy vs. 3.5 for IDET	Not randomised. Not intention to treat analysis as 3 patients in standard therapy subsequently approved for IDET.
			Pain score on 10 point VAS at 12 and 24 months	7.5 for standard therapy (in 12 patients) vs 3 in IDET (35 patients_
			% of patients with >50% reduction in pain and return to work	1 patient in control group vs. 60% fir IDET.
			% of patients with complete relief of pain, no use of opioids, and return to work.	none in control group vs. 23% in IDET group at 12 months

Comment(s)

Intradiscal electrothermal annuloplasty is an interesting technique that from a patho-physiological perspective makes some sense. The idea that the tear in an internal disc derangement may be repaired through the use of a percutaneous procedure is certainly attractive. This is especially so as there are few, if any other effective methods of treating the condition. In these studies, both apparently from the same group, there is limited evidence for the use if IDET. However, both studies include significant methodological flaws and contain small numbers of patients. The authors arguments that IDET may be of particular benefit in certain subgroups of patients is perhaps a little ambitious on the basis of the data presented. However, in this evidence poor area of clinical practice the results are interesting and will hopefully prompt future more rigorous trials. It should be noted that patients in these studies underwent a rigorous diagnostic procedure to ensure that the source of pain was due to internal disc disruption.

Clinical Bottom Line

IDET shows promise as a technique for the treatment of proven painful internal disc disruption. There is insufficient evidence to recommend it widely at this stage.

Level of Evidence

Level 2 - Studies considered were neither 1 or 3.

References

1. Kevin J. Pauza MD, , a, b, Susan Howell BS, RNb, Paul Dreyfuss MDb, John H. Peloza MDc, Kathryn Dawson PhDd and Nikolai Bogduk MD, DSc A randomized, placebo-controlled trial of intradiscal electrothermal therapy for the treatment of discogenic low back pain The Spine Journal 2004;4:27-35
2. Nikolai Bogduk MD, PhD, DSca, and Michael Karasek MD Two-year follow-up of a controlled trial of intradiscal electrothermal anuloplasty for chronic low back pain resulting from internal disc disruption The Spine Journal 2002;2:343-350