Interventional Procedure Consultation Document - Interspinous distraction procedures for spinal stenosis causing neurogenic claudication in the lumbar spine
NATIONAL INSTITUTE FOR HEALTH AND CLINICAL EXCELLENCE
Interventional Procedure Consultation Document
Interspinous distraction procedures for spinal stenosis causing neurogenic claudication in the lumbar spine
The National Institute for Health and Clinical Excellence is examining interspinous distraction procedures for spinal stenosis causing neurogenic claudication in the lumbar spine and will publish guidance on their 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 procedures. The Advisory Committee has made provisional recommendations about interspinous distraction procedures for spinal stenosis causing neurogenic claudication in the lumbar spine.
Note that this document is not the Institute's formal guidance on these procedures. The recommendations are provisional and may change after consultation.
The process that the Institute will follow after the consultation period ends is as follows.
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: 20 December 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 there are no major safety concerns associated with interspinous distraction procedures for spinal stenosis causing neurogenic claudication in the lumbar spine, but evidence of efficacy is limited and is confined to the medium and short term. These procedures should only be used in the context of special arrangements for consent, audit and research.
Clinicians wishing to undertake interspinous distraction procedures for spinal stenosis causing neurogenic claudication in the lumbar spine should take the following actions.
Publication of long-term efficacy data will be useful. The Institute may review the procedures upon publication of further evidence.
Lumbar spinal stenosis is a narrowing of the spinal canal in the lower part of the back. Unlike disc rupture, lumbar spinal canal stenosis does not normally cause pain in the legs at rest. Characteristically, discomfort in the form of nerve pain, tingling, numbness, or sometimes weakness, occurs when standing or walking any distance (extension), and is relieved by sitting or leaning forwards (flexion). Because this is a degenerative condition, spontaneous resolution is uncommon, and persistence of symptoms, or progressive reduction of standing time and walking distance is common.
|2.1.2||Non-surgical therapy commonly includes conservative treatment with medication. Non-steroidal anti-inflammatory medication may help to relieve symptoms.|
|2.1.3||Surgical treatment most commonly involves laminectomy in which the nerve roots are decompressed by opening the spinal canal and removing the degenerative disc material. Sometimes, when bony instability or severe back pain are particular problems, laminectomy may be supplemented by a bony fusion.|
|2.2||Outline of the procedure|
|2.2.1||Implants are placed between adjacent spinous processes to act as physical blocks to extension (and thus lumbar canal narrowing) on standing or walking, relieving pressure on the nerves. These procedures may have a role between medical symptom control and the more invasive procedure of laminectomy.|
The patient is positioned with the spine flexed, and the operative level (or levels) is confirmed by X-rays. A midline incision is made over the appropriate spinal level and deepened to display the spinous processes and their intact joining (interspinous) ligament. The blocking device is sized and positioned in the space between the flexed spinous processes.
A multicentre randomised controlled trial (RCT) compared interspinous implants with non-surgical care in patients with or without back pain, but with leg pain relieved by flexion and CT- or MRI-confirmed spinal stenosis. At 2 year' follow-up there was a 45% improvement in symptom severity from baseline in patients who had the implants, compared with a 7% improvement in the control group (p < 0.001). Physical function scores improved by 44% in patients treated with an implant whereas the scores for those treated medically deteriorated by 0.4% (p < 0.001).
|2.3.2||In the same study, patients who received implants had significantly improved quality of life outcomes at 6 weeks, 6 months, and 1 year postoperatively. At 1 year, 59% of patients who received implants had clinically successful outcomes as assessed by improvements in symptom severity, physical function score and post-treatment satisfaction score (n = 88). Of those who had non-surgical treatment, 12% had a clinically successful outcome (n = 68) (these figures were derived from charts presented in the publication).|
|2.3.3||In a case series of 10 patients with mild to moderate symptoms undergoing interspinous implant insertion, symptom severity improved in 40% (4/10) of patients, and 10% (1/10) showed significant improvement in physical function at a median follow-up of 11 months. For more details, refer to the sources of evidence (see Appendix).|
The Specialist Advisors noted that, given the fluctuating symptoms associated with this condition, the assessment of outcomes in clinical studies may be unreliable. Some Advisors questioned the long-term efficacy of the procedure.
In an RCT, 6% (5/88) of patients treated needed re-operation during the first year after implantation. At 2 years' follow-up, there had been one case in 100 patients who had undergone interspinous implantation of each of the following: respiratory distress, ischaemic episode, pulmonary oedema, wound dehiscence, wound swelling, haematoma, and incision pain. There was one incident each of implant misplacement, implant migration, spinous fracture, and increased pain at the implant level. For more details, refer to the sources of evidence (see Appendix).
|2.4.2||The Specialist Advisors noted concerns about additional pain in adjacent levels, device migration, and potential infection.|
|2.5.1||It was noted that all the evidence was based on a single type of device.|
The Institute is developing guidance on non-rigid stabilisation techniques for the treatment of low back pain (www.nice.org.uk/ip_306).
Chairman, Interventional Procedures Advisory Committee
|Appendix:||Sources of evidence|
The following document, which summarises the evidence, was considered by the Interventional Procedures Advisory Committee when making its provisional recommendations.
Available from: www.nice.org.uk/ip191overview
This page was last updated: 30 March 2010