Interventional procedure consultation document - percutaneous intradiscal radiofrequency thermocoagulation for lower back pain (second consultation)

The National Institute for Clinical Excellence is examining percutaneous intradiscal radiofrequency thermocoagulation 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 radiofrequency thermocoagulation 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• The Advisory Committee will then prepare draft guidance which will be the basis for the Institute's guidance on the use of the procedure in the NHS in England, Wales and Scotland.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 radiofrequency thermocoagulation 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 radiofrequency thermocoagulation 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 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 radiofrequency thermocoagulation 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. 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 typically 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 radiofrequency thermocoagulation is particularly indicated in patients with persistent lower back pain.

Percutaneous intradiscal radiofrequency thermocoagulation is a procedure that allows the controlled delivery of heat to the intervertebral disc via an electrode or coil. Patients are sedated and local anaesthetic is infiltrated over the affected disc. Under fluoroscopic guidance, a needle is inserted into the disc. The electrode or flexible catheter is then introduced into the centre of the nucleus through the needle, slowly heated to 50-80°C and kept at that temperature for 90-360 seconds.

In one uncontrolled study of 39 patients there was a reported improvement in pain at a mean follow-up of 16 months. Two subsequent studies, including one randomised controlled trial of 28 patients comparing percutaneous intradiscal radiofrequency thermocoagulation with placebo, reported no statistically significant differences between preoperative pain levels, and pain levels at final follow-up. All three studies were small with short-term follow-up, and two were uncontrolled. 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 and trying to determine any benefit of 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 considered the current published evidence had not demonstrated benefit.

In the one randomised controlled trial of this procedure the authors stated that no complications were observed during or after the procedure. It is difficult to know, however, whether this is because complications are uncommon or whether complications were not systematically detected and reported in the available studies.

The Specialist Advisors did not report any particular safety concerns, but noted that potential adverse events included infection and nerve root damage.

The evidence is based on small numbers of patients.

The efficacy evidence is difficult to interpret. It is unclear whether the improvements are the result of the procedure or the natural course of the condition.

Higher doses of thermal energy may be hazardous and should be used with particular caution.

The Institute has also issued provisional recommendations, and is currently consulting on, percutaneous intradiscal electrothermal therapy for lower back pain. www.nice.org.uk/ip073consultation

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 radiofrequency thermocoagulation for lower back pain, April, 2003

Available from: www.nice.org.uk/ip181boverview