Interventional procedure consultation document

Percutaneous intradiscal laser ablation in the lumbar spine

Discs that act like cushions between the bones of the spine can sometimes get damaged and protrude onto nerves, causing back and leg pain, and numbness and weakness in the leg.

In percutaneous intradiscal laser ablation, a needle is inserted through the outer cover of the disc, into its jelly-like centre. A laser is then inserted through the needle to destroy part of the disc, with the aim of shrinking it.

The National Institute for Health and Clinical Excellence (NICE) is examining percutaneous intradiscal laser ablation in the lumbar spine and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. NICE’s Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about percutaneous intradiscal laser ablation in the lumbar spine.

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 provisional recommendations
• the identification of factual inaccuracies
• additional relevant evidence, with bibliographic references where possible.

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

The process that NICE 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• The Advisory Committee will then prepare draft guidance which will be the basis for NICE’s guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.

For further details, see the Interventional Procedures Programme manual, which is available from the NICE website (www.nice.org.uk/ipprogrammemanual).

NICE is committed to promoting through its guidance race and disability equality and equality between men and women, and to eliminating all forms of discrimination. One of the ways we do this is by trying to involve as wide a range of people and interest groups as possible in the development of our guidance on interventional procedures. In particular, we aim to encourage people and organisations from groups in the population who might not normally comment on our guidance to do so. We also ask consultees to highlight any ways in which draft guidance fails to promote equality or tackle discrimination and give suggestions for how it might be improved. NICE reserves the right to summarise and edit comments received during consultations, or not to publish them at all, where in the reasonable opinion of NICE, the comments are voluminous, publication would be unlawful or publication would otherwise be inappropriate.

Closing date for comments: 16 June 2010

Target date for publication of guidance: September 2010

1   Provisional recommendations

1.1  Current evidence on the safety and efficacy of percutaneous intradiscal laser ablation in the lumbar spine is adequate to support the use of this procedure provided that normal arrangements are in place for clinical governance, consent and audit.

1.2  Patients selected for the procedure should be limited to those with severe pain refractory to conservative treatment, in whom imaging studies show bulging of an intact disc, and who do not have neurological deficit requiring surgical decompression.

2  The procedure

2.1  Indications and current treatments

2.1.1  Symptomatic herniation (prolapse) of a lumbar intravertebral disc is a common cause of chronic low back pain and sciatica. Disc herniation is a result of the protrusion of the nucleus pulposus through a tear in the annulus fibrosus. The annulus fibrosus may rupture completely, resulting in an extruded disc, or it may remain intact but stretched, resulting in a contained (bulging) disc prolapse. Protruding discs may compress one or more nerve roots, resulting in pain and numbness in the leg.  

2.1.2  Conservative treatment options include rest, analgesic or anti-inflammatory medication, epidural injection and physical therapies. Current surgical treatment options include microdiscectomy, percutaneous intradiscal electrothermal therapy, percutaneous intradiscal radiofrequency thermocoagulation and percutaneous disc decompression using coblation. Surgical decompression is considered when there is nerve compression or persistent symptoms that are unresponsive to conservative treatment.

2.2  Outline of the procedure

2.2.1  The aim of percutaneous intradiscal laser ablation (also commonly referred to in the literature as percutaneous laser disc decompression) is to vaporise part of a prolapsed disc. It can only be carried out if the prolapse is contained (i.e. the disc is bulging but the nucleus pulposus has not extruded through the annulus fibrosus).

2.2.2  The procedure is usually carried out under local anaesthetia and sedation, with the patient in the prone position. Under fluoroscopic guidance, a spinal needle is inserted through the annulus fibrosus into the nucleus pulposus, and an optical fibre is introduced through the needle. Laser energy is then delivered through the optical fibre to vaporise part of the nucleus pulposus.

2.2.3  Several types of laser are available for this procedure.

 

Sections 2.3 and 2.4 describe efficacy and safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview, available at www.nice.org.uk/IP75aoverview

2.3  Efficacy

2.3.1  A non-randomised comparative study of 1000 patients reported ‘excellent’ or ‘good’ MacNab criteria scores (pain relived by 50% or more and improved motor function) in 84% (419/500) of patients treated by the procedure and 86% (428/500) of patients treated by microdiscectomy at 2-year follow-up (significance not stated).

2.3.2  A non-randomised comparative study of 106 patients reported ‘excellent’ MacNab criteria scores (pain relived by 75% or more and no limitation of motor function) in 48% (29/60) of patients treated by the procedure compared with 48% (22/46) of patients treated by automated percutaneous lumbar discectomy (APLD) (follow-up not stated; difference reported as not significant).

2.3.3  A case series of 518 patients reported an overall success rate (using MacNab criteria; not otherwise described) of 75% (absolute figures and follow-up not stated).

2.3.4  The non-randomised comparative study of 1000 patients reported reoperation for herniation or persistent leg or back pain in 3% (16/500) of patients treated by the procedure and 7% (35/500) of patients treated by microdiscectomy at a mean 2-year follow-up.

2.3.5  A case series of 576 patients reported that 61% of patients were satisfied with the overall outcome of the procedure (absolute figures and follow-up not stated).

2.3.6  The Specialist Advisers listed key efficacy outcomes as recurrence rate, reoperation rate, leg and back pain score, Oswestry Disability Index score and failure to decompress the nerve.

2.4  Safety

2.4.1  Aseptic discitis (post-procedural inflammatory pain) requiring up to 3 days of hospitalisation with steroid treatment was reported in 2 patients treated by the procedure in a non-randomised comparative study of 81 patients. Case series of 576 and 518 patients reported aseptic discitis in 4 and 2 patients respectively. In the second series both patients developed aseptic discitis up to 4 days after the procedure (not otherwise described) and treated with bed rest and analgesics.

2.4.2  Septic discitis 3 days after the procedure (confirmed by magnetic resonance imaging [MRI] and needle puncture culture, which was positive for Staphylococcus aureus) was reported in 2 patients in the case series of 518 patients. Both patients were treated with parenteral vancomycin for 6 weeks. Intervertebral disc infection (not otherwise described) was reported in no patients treated by the procedure and 1 patient treated by APLD in the non-randomised comparative study of 106 patients (timing of event not stated).

2.4.3  Subchondral vertebral osteonecrosis (confirmed by MRI) was reported in 2% (4/182) of patients in the case series of 182 patients: 1 patient underwent surgical treatment for persistent severe back pain which resolved 1 year after the initial procedure, 3 patients had conservative management and pain had diminished at 2-year follow-up after the initial procedure.

2.4.4  A case series of 10 patients who required salvage operations after the procedure to address herniated discs reported that all patients showed evidence of heat-induced cell necrosis and carbonisation, with herniating masses completely compressing and adhering to nerve roots in all patients after the procedure.  

2.4.5  The Specialist Advisers stated that bowel perforation was described in the literature. They considered theoretical adverse events to include dural tear, heat damage due to incorrect placement of probe, recurrent protrusion of disc, nerve damage, infection, vertebral body collapse, loss of disc height and perineural scarring.

3  Further information

3.1  This guidance is a review of ‘Laser lumbar discectomy’ NICE interventional procedures guidance 27 (2003). For related NICE guidance see www.nice.org.uk.

Bruce Campbell

Chairman, Interventional Procedures Advisory Committee
April 2010

_{Personal data will not be posted on the NICE website. In accordance with the Data Protection Act names will be anonymised, other than in circumstances where explicit permission has been given.}

 _{It is the responsibility of consultees to accurately cite academic work in order that they can be validated.}