The National Institute for Health and Clinical Excellence is examining automated percutaneous mechanical lumbar discectomy 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 automated percutaneous mechanical lumbar discectomy.

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 recommendations
• 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• The Advisory Committee will then prepare draft guidance which will be the basis for the Institute's guidance on the use of the procedure in the NHS in England, Wales and Scotland.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 Interventional Procedures Programme manual, which is available from the Institute's website (www.nice.org.uk/ipprogrammemanual).

Closing date for comments: 21 June 2005
Target date for publication of guidance: August 2005

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

Current evidence suggests that there are no major safety concerns associated with automated percutaneous mechanical lumbar discectomy. However, the limited evidence of efficacy is based on uncontrolled case series of heterogeneous groups of patients, and randomised controlled trials show that this procedure is less efficacious than open discectomy. In view of the uncertainties about the efficacy of the procedure, it should not be used without special arrangements for consent, and for audit or research.

Clinicians wishing to undertake automated percutaneous mechanical lumbar discectomy 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. In addition, use of the Institute's Information for the public is recommended.
• Audit and review clinical outcomes of all patients having automated mechanical percutaneous lumbar discectomy. The Institute may review the procedure upon publication of further evidence.
  

Lumbar radicular pain, also known as sciatica, refers to pain that begins in the lower back and radiates down the leg. It is commonly caused by a herniated (or prolapsed) lumbar intervertebral disc. The herniation is a result of a protrusion of the nucleus pulposus through a tear in the surrounding annulus fibrosus. The annulus fibrosus may rupture completely, resulting in an extruded disc, or may remain intact but stretched, resulting in a contained disc prolapse. This may then compress one or more nerve roots, causing pain, numbness or weakness in the leg.

In a randomised controlled trial (RCT) of 71 patients, 29% (9/31) had a successful outcome after automated percutaneous lumbar discectomy, compared with 80% (32/40) of patients after microdiscectomy (p < 0.001). In a second RCT, 41% (7/17) of patients had an 'excellent' or 'good' outcome after automated percutaneous lumbar discectomy, compared with 40% (4/10) of patients after conventional discectomy. A third RCT compared automated percutaneous lumbar discectomy with chemonucleolysis and found that significantly more patients had a successful result after chemonucleolysis (61% [44/72] versus 44% [30/69], p < 0.05).

Two large case series reported that 68% (707/1047) and 82% (1216/1474) of patients had an 'excellent' or 'good' result at 6 months and 1 year respectively. A third case series reported an overall success rate of 45% (52/115) after a mean follow-up of 55 months. In two further case series reports, 94% (47/50) and 52% (95/182) of patients were satisfied after mean follow-ups of 6 months and 2.5 years respectively. For more details, refer to the sources of evidence (see Appendix).

Few complications were reported. Three studies reported discitis in between 0.2% (2/1146) and 1% (2/182) of patients. Two studies reported haematoma in 0.1% (1/1146) and 1.4% (1/69) of patients. Other complications included back muscle spasms, minor bleeding, minor radicular injury and vasovagal syncope. For more details, refer to the sources of evidence (see Appendix).

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

Interventional procedure overview of automated percutaneous mechanical lumbar discectomy, February 2005

Available from: www.nice.org.uk/ip278overview