Interventional procedure consultation document - percutaneous intradiscal electrothermal therapy for lower back pain

The National Institute for Clinical Excellence is examining percutaneous intradiscal electrothermal therapy for lower back pain and will publish guidance on its safety and efficacy to the NHS in England, Wales and Scotland. The Institute's Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisors, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about percutaneous intradiscal electrothermal therapy for lower back pain.

This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:

• comments on the preliminary recommendation
• the identification of factual inaccuracies
• additional relevant evidence.

Note that this document is not the Institute's formal guidance on this procedure. The recommendations are provisional and may change after consultation.

The process that the Institute will follow after the consultation period ends is as follows:

• The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
• The Advisory Committee will then prepare draft guidance which will be the basis for the Institute's guidance on the use of the procedure in the NHS in England, Wales and Scotland.

For further details, see the Interim Guide to the Interventional Procedures Programme, which is available from the Institute's website (www.nice.org.uk/ip).

Closing date for comments: 25 May 2004

Target date for publication of guidance: August 2004

Note that this document is not the Institute's guidance on this procedure. The recommendations are provisional and may change after consultation.

Current evidence on the safety and efficacy of percutaneous intradiscal electrothermal therapy for lower back pain does not appear adequate to support the use of this procedure without special arrangements for consent and for audit or research.

Clinicians wishing to undertake percutaneous intradiscal electrothermal therapy for lower back pain should take the following actions.

• Inform the clinical governance leads in their Trusts.
• Ensure that patients understand the uncertainty about the procedure's safety and efficacy and provide them with clear written information. Use of the Institute's Information for the Public is recommended.
• Audit and review clinical outcomes of all patients having percutaneous intradiscal electrothermal therapy for lower back pain.

Further research will be useful in reducing the current uncertainty and clinicians are encouraged to collect longer term follow-up data. The Institute may review the procedure upon publication of further evidence.

Chronic back pain is a common condition that affects a considerable proportion of the population. In most individuals the pain resolves spontaneously within several months. However, for some people the pain persists, despite specific causes of back pain such as herniated discs, osteoporosis and fractures being excluded. Increasingly, this pain is being attributed to degeneration of the intervertebral disc, and referred to as discogenic back pain.

Typically, first-line treatment for chronic discogenic back pain is conservative, consisting of pharmacotherapy and/or a multidisciplinary programme which may include exercises, education and behavioural therapy. Where these regimes have failed, patients may then choose to continue with conservative management or to undergo surgery (spinal fusion). Intradiscal electrothermal therapy is indicated for patients with discogenic lower back pain who have not responded to conservative treatment and who have opted not to have surgery.

Percutaneous intradiscal electrothermal therapy is normally performed under local anaesthetic and light sedation. An introducer needle is inserted into the painful disc under fluoroscopic guidance. An electrode or flexible catheter is then introduced into the disc through the needle and is guided to a position covering the entire posterior wall of the disc. Once in position, the catheter is slowly heated up to 90°C and kept at that temperature for 15-17 minutes.

From the published evidence, the majority of patients reported a decrease in pain following the procedure as measured by visual analogue scales. In a randomised control trial, 78% (25/32) of patients reported an improvement in pain 6 months after the procedure, compared with 46% (11/24) of patients in the control group. Only 38% (12/32) of patients treated by electrothermal therapy experienced more than 50% pain relief, compared with 33% (8/24) of patients who underwent a sham procedure. The reporting of improvement in pain varied among the case series from 48% (38/79) of patients reporting more than 50% pain relief at 6 months to 72% (42/58) of patients experiencing at least a two-point improvement in pain at 24 months as measured by a ten- point visual analogue scale. For more details, refer to the sources of evidence (see Appendix).

There was some evidence to indicate that patients experienced an improvement in physical function, bodily pain and disability scores following the procedure. For more details, refer to the sources of evidence (see Appendix).

The natural history of this condition, the difficulty in assessing pain and the potential for a placebo effect all present problems when interpreting the evidence on this procedure. For more details, refer to the sources of evidence (see Appendix).

The Specialist Advisors expressed uncertainty regarding the efficacy of this procedure. They felt that the current published evidence had not provided clear evidence of benefit.

Complications were described in only four of the studies. Most of the complications were of a transient nature. The incidence of complications ranged from 0% (0/58) to 15% (5/33) and included increasing radicular pain (5/33), paraesthesia and numbness in the thighs (2/79), and foot drop (1/79). In one study, one patient developed a cerebro-spinal leak. There were also two case reports of cauda equina syndrome and two cases of vertebral osteonecrosis following the procedure. For more details, refer to the sources of evidence (see Appendix).

The Specialist Advisors did not report any particular safety concerns, although persisting pain and exacerbation of pain, puncture of dura or bowel, nerve root damage and infection were noted as potential complications of intradiscal electrothermal therapy.

The majority of the studies reported on small numbers of highly selected patients.

The Institute has also issued provisional recommendations, and is currently consulting on, percutaneous intradiscal radiofrequency thermocoagulation for lower back pain /ip181consultation2

The following document, which summarises the evidence, was considered by the Interventional Procedures Advisory Committee when making its provisional recommendations.

• Interventional procedure overview of percutaneous intradiscal electrothermal therapy, April, 2003

Available from: www.nice.org.uk/ip073overview