NATIONAL INSTITUTE FOR HEALTH AND CLINICAL EXCELLENCE

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1 NATIONAL INSTITUTE FOR HEALTH AND CLINICAL EXCELLENCE INTERVENTIONAL PROCEDURES PROGRAMME Interventional procedure overview of percutaneous intradiscal electrothermal therapy for low back pain Discogenic pain in the lower back happens when one or more of the tough discs that sit between the bones (vertebrae) in the spine become worn. In this procedure a needle is put into the affected disc (a video image similar to an X- ray is used to help find the correct position). A narrow tube is then passed through this needle into the disc. This is then heated slowly and kept in place for a few minutes. Introduction The National Institute for Health and Clinical Excellence (NICE) has prepared this overview to help members of the Interventional Procedures Advisory Committee (IPAC) make recommendations about the safety and efficacy of an interventional procedure. It is based on a rapid review of the medical literature and specialist opinion. It should not be regarded as a definitive assessment of the procedure. Date prepared This overview was prepared in February Procedure name Percutaneous intradiscal electrothermal therapy for low back pain Specialty societies British Orthopaedic Association Association of Anaesthetists of Great Britain and Ireland British Society of Skeletal Radiology. Page 1 of 23

2 Description Indications and current treatment Chronic back pain is a common condition that affects a considerable proportion of the population. In the majority of individuals pain resolves spontaneously within several months. However, for some people pain persists, despite absence of specific causes of back pain such as herniated discs, osteoporosis and fractures. Increasingly this pain is being attributed to degeneration of the intervertebral disc, and referred to as discogenic back pain Few treatment options exist for individuals with chronic back pain. First-line treatment is typically a conservative management strategy, consisting of pharmacotherapy and/or a multidisciplinary programme that may include exercise, education and behavioural therapy. Patients who fail to respond to this regime then have the choice to continue with conservative management or to undergo surgery (spinal fusion, radiofrequency ablation, or laser lumbar discectomy). Functional ability in patients with symptomatic degenerative disc disease is often evaluated using the Oswestry Disability Index (ODI) a 10-item questionnaire scoring from 0% to 100% (low scores are better). What the procedure involves The aim is to disrupt the nerve endings within the annulus of the disc that carry pain signals from the site and to stiffen the annulus. The disc is targeted using provocative discography. Percutaneous intradiscal electrothermal therapy (IDET) is normally performed with the patient under a 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 adjacent to the posterior wall of the disc. Once in position, the catheter is slowly heated to up to 90 C for up to 15 minutes. OPCS code List of studies included in the overview This overview is based on 1068 patients from one meta analysis 1, one randomised controlled trial 2, two non-randomised controlled studies 3,4, one case series 5, and two case reports 6,7. Other studies that were considered to be relevant to the procedure but were not included in the main extraction table (table 2) have been listed in appendix A. Page 2 of 23

3 Efficacy A meta-analysis of 805 patients from 17 studies reported that the pooled mean pain score (measured on a 10 point visual analogue scale) following IDET improved by 2.9 points in the 13 studies that reported on pain outcomes (95% confidence interval [CI] 2.5 to 3.4) (follow-up period varied) 8. In the meta-analysis 3 studies reported on ODI scores. The pooled mean reduction in the ODI score was 9.9 points (95% CI 2.0 to 11.9) (follow-up period varied). A non-randomised controlled study of 109 patients treated by IDET or pain relieving injection reported that pain (measured on a 10 point visual analogue scale) improved significantly from baseline in both groups (measurement of significance not reported). In the same study, the pain-relieving injection group reported greater pain relief (2.2 points at 7.7-month follow-up) than the IDET group (1.3 points at 15.5-month follow-up) (p = 0.01) 3. A randomised controlled trial (RCT) of 57 patients reported that there was no statistically significant difference in the ODI scores of patients treated by IDET from those treated by a sham procedure. Mean scores improved between baseline and 6-month follow-up (from to points) in the IDET group and worsened (from to points) in the sham group (p = 0.489) 2. A non randomised controlled study of 42 patients treated with either IDET or disc radiofrequency ablation reported that pain scores (measured on a 10 point visual analogue scale) improved more following IDET (7.4 points to 1.4 points) than following radiofrequency ablation (6.6 points to 4.4 points) at 1- year follow-up (measurement of significance not reported) 4. A case series of 53 patients reported that functional ability (measured by ODI score) had improved significantly from points at baseline to 5.15 points at 1-year follow-up (p = 0.001) 5. Narcotic analgesic medication was required by 51% of the patients at baseline and 13% at 1-year follow-up (absolute figures and measurement of significance not reported). In the same study, at 56-month follow-up, 6% (3/53) of patients had resumed full work duties, 17% (9/53) were working with the only restriction being heavy lifting, and 25% (13/53) of patients had resumed light duties only. Safety A meta-analysis of 805 patients from 17 studies reported that the overall incidence of complications following IDET was 0.8% (95% CI 0.2 to 1.4%) 8. Within this meta-analysis 6 studies, including a total of 246 patients, reported no complications. An RCT of 57 patients reported that transient radiculopathy (< 6 weeks) occurred in 11% (4/38) of patients treated by IDET and 5% (1/19) of patients in the placebo group (measurement of significance not reported); there were no serious complications in either study group 2. A case series of 53 patients reported that a complication occurred in 2% (1/53) of patients (length of follow up and complication not described) 5. Page 3 of 23

4 A case report of 1 patient described paraesthesia and dysaethesia in the left leg at 6-month follow-up after a procedure in which 3 different catheters had to be used and the catheter tip had broken off inside the disc space. Surgical removal of the catheter tip via a longitudinal durotomy resolved the dysaethetic symptoms at 3-month subsequent follow-up 6. A case report of 1 patient described pain intensification following IDET. Magnetic resonance imaging at 3-month follow-up indicated diffuse narrow oedema of the L2 vertebral body consistent with osteonecrosis; this had resolved at 12 months follow up 7. Literature review Rapid review of literature The medical literature was searched to identify studies and reviews relevant to percutaneous intradiscal electrothermal therapy for lower back pain. Searches were conducted of the following databases, covering the period from their commencement to and updated to : MEDLINE, PREMEDLINE, EMBASE, Cochrane Library and other databases. Trial registries and the Internet were also searched. No language restriction was applied to the searches (see appendix C for details of search strategy). The following selection criteria (table 1) were applied to the abstracts identified by the literature search. Where selection criteria could not be determined from the abstracts the full paper was retrieved. Table 1 Inclusion criteria for identification of relevant studies Characteristic Publication type Patient Intervention/test Outcome Language Criteria Clinical studies were included. Emphasis was placed on identifying good quality studies. Abstracts were excluded where no clinical outcomes were reported, or where the paper was a review, editorial, or a laboratory or animal study. Conference abstracts were also excluded because of the difficulty of appraising study methodology, unless they reported specific adverse events that were not available in the published literature. Patients with low back pain Percutaneous intradiscal electrothermal therapy Articles were retrieved if the abstract contained information relevant to the safety and/or efficacy. Non-English-language articles were excluded unless they were thought to add substantively to the English-language evidence base. Page 4 of 23

5 Existing assessments of this procedure Related NICE guidance Below is a list of NICE guidance related to this procedure. Appendix B gives details of the recommendations made in each piece of guidance listed. Interventional procedures Non-rigid stabilisation techniques for the treatment of low back pain NICE interventional procedures guidance 183 (2006). Available from Percutaneous intradiscal radiofrequency thermocoagulation for lower back pain NICE interventional procedures guidance 083 (2004). Available from Percutaneous intradiscal electrothermal therapy for lower back pain. NICE interventional procedures guidance 081 (2004). Review in progress (this overview). Available from Prosthetic lumbar intervertebral disc replacement NICE interventional procedures guidance 100 (2004). Review in progress. Available from Laser lumbar discectomy NICE interventional procedures guidance 027 (2003). Available from Percutaneous endoscopic laser lumbar discectomy NICE interventional procedures guidance XXX (2009) in progress. Technology appraisals None Clinical guidelines None Public health guidance None Page 5 of 23

6 Page 6 of 23 Table 2 Summary of key efficacy and safety findings on percutaneous intradiscal electrothermal therapy for low back pain Abbreviations used: IDET, intradiscal electrothermal therapy; LBOS, low back-pain outcome score; ODI, Oswestry Disability Index; RF, radiofrequency; Study details Key efficacy findings Key safety findings Comments Appleby D (2006) 8 Pain Complications Meta analysis USA international studies Study period: Not reported Study population: Not reported, Age: Not reported. Sex: Not reported n = 805 (from 17 studies) Inclusion criteria: varied between studies but all required duration of symptoms for a minimum of 3 months and failure of conservative care. Technique: IDET technique varied between studies Follow-up: Range 6 to 34 months Conflict of interest: first author is employee of manufacturer. Pain was evaluated by visual analogue scales from 0 (no pain) to 10 (worst possible pain). Thirteen studies reported on pain outcomes following IDET. The pooled mean pain score improved by 2.9 points (95% CI 2.5 to 3.4) (follow-up period not reported) Functional ability The bodily pain and physical functioning subscales of the SF-36 health survey were used. Each rates from 1 to 100 with low scores representing more limitation. Four studies reported on physical function scores. The pooled mean improved by 21.1 points (95% CI 23.4 to 28.8). (follow-up period not reported) 4 studies reported on bodily pain scores. The pooled mean improved by 18.0 points (95% CI 11.9 to 24.1). (follow-up period not reported). 3 studies reported on ODI scores. The pooled mean improved by 7.0 points (95% CI 2.0 to 11.9). (follow-up period not reported). 6 studies including a total of 246 patients reported no complications. The overall incidence of complications was 0.8% (95% CI 0.2 to 1.4%). Complication N= Status Burning sensation in one leg 1 Resolved Paraesthesia and numbness 2 Resolved in thighs Drop foot 1 Resolved Increasing back and thigh 1 Fusion pain Increasing lower leg pain 1 Lost to follow up Headache 1 Resolved Increase in hernia size following IDET 1 Interbody fusion Increasing radicular pain 5 Resolved in 4, surgery in 1 Cerebral spinal fluid visualised 1 Resolved Device failure due to scar tissue 1 Interbody fusion Increasing low back pain 1 Fusion Nerve root injury 1 Resolved Increased disc herniation 1 Fusion Faecal incontinence 1 Resolved Non-dermatomal leg pain 2 Resolved Discitis 1 Fusion Anterolisthesis 1 Fusion Medline literature search only. No comparative data presented. Data from the IDET arm of controlled trials are analysed as a case series. Random effects model used for analysis of efficacy and fixed effects model for incidence of complications. The follow-up period of studies was mixed in analysis, and patient selection varied between studies. Only outcomes in which 4 studies or more had reported were considered for analysis. Follow-up period at which complications occurred is not reported. No statistical test for heterogeneity presented The ODI is a 10-item questionnaire scoring from 0% to 100% (low scores better).

7 Abbreviations used: IDET, intradiscal electrothermal therapy; LBOS, low back-pain outcome score; ODI, Oswestry Disability Index; RF, radiofrequency; Study details Key efficacy findings Key safety findings Comments Freeman B J C (2005) 2 Operative success Complications Success was defined as no neurological deficit,. Randomised controlled trial improvement in LBOS of 7 or more points, and improvement in the SF-36 subscales of physical functioning and bodily pain index >1 Standard deviation Australia from the mean. Study period: Nov 1999 to Dec 2001 Study population: Chronic discogenic low back pain. Age: 39 years. Sex: 56% male. Mean ODI score 41 points, mean LBOS score 38 points. n = 57 (38 IDET) Inclusion criteria: One or two level pain, symptoms for 3+ months, failure to improve with 6 weeks of conservative therapy. No patient in either treatment group reported a successful outcome. Mean LBOS (low scores worse) (not otherwise defined) (p=0.111) Baseline 6 months IDET (±5.25) (±3.61) Placebo (±3.00) (±1.60) Mean ODI (low scores better) (0 to 100 points) (p = 0.489) Baseline 6 months IDET (±14.80) (±16.28) Placebo (±11.84) (±11.29) Transient radiculopathy (< 6 weeks) occurred in 11% (4/38) of patients in the IDET group and 5% (1/19) of patients in the placebo group (measurement of significance not reported). There were no other serious adverse events in either study group Potentially some same IDET patients as included in Appleby (2006) however comparative data reported here. Crossover to IDET offered to patients allocated to placebo after unblinding at 6 months. Randomisation at 2:1 ratio, method and concealment not reported. Described as double blind. Patient demographic and clinical status were not significantly different between groups at baseline. Technique: Under local anesthesia and fluoroscopic guidance IDET via a 17G needle to 90 C vs sham treatment. Both groups received 100mg cefazolin and standard rehabilitation programme. Mean SF-36 physical functioning (low scores worse) (1 to 100 points) (p = 0.819) Baseline 6 months IDET (±23.01) (±24.20) Placebo (±15.37) (±20.14) 4% (2/57) of patients in the IDET group broke protocol and were excluded from analysis. Follow-up: 6 months Conflict of interest: supported by manufacturer. Mean SF-36 bodily pain index (low scores worse) (1 to 100 points) (p = 0.659) Baseline 6 months IDET (±15.97) (±21.37) Placebo (±13.45) (±15.29) Page 7 of 23

8 Abbreviations used: IDET, intradiscal electrothermal therapy; LBOS, low back-pain outcome score; ODI, Oswestry Disability Index; RF, radiofrequency; Study details Key efficacy findings Key safety findings Comments Derby R (2004) 3 Pain Safety outcomes were not reported on. Non randomised controlled trial USA Study period: Jan 200 to Oct 2002 Study population: Chronic discogenic low back pain. Age: 42 years. Sex: 45% male. n = 109 (74 IDET) Inclusion criteria: One or two level pain, failure to improve with conservative therapy. Technique: Under fluoroscopic guidance IDET via a 17G introducer to 90 C for 16.5 minutes, followed by intradiscal antibiotic and bupivicaine treatment vs injection of 0.5% chondroitin sulfate, 20% glucosamine hydrochloride, 12% DMSO, and 2% bupivacaine during diagnosis discography. Follow-up: 7.7 to 15.5 months mean Pain was evaluated by visual analogue scales from 0 (no pain) to 10 (worst possible pain). Pain relief compared to baseline was significantly improved in both groups. Pain relief improved more in the injection group (2.2 points), than in the IDET group (1.3 points) which was a marginally significant difference between the groups (p = 0.01). There was a significant difference in the occurrence of pain flare-up between the injection group (81%) and the IDET group (69%) (absolute figures and measurement of significance not reported). Patient satisfaction Assessed using an evaluation sheet developed for the study. 47.8% of patients treated by IDET reported feeling better compared to 65.6% of patients in the injection group. Potentially some same IDET patients as included in Appleby (2006) however comparative data reported here. Retrospective case review from a prospectively collected database. 7 of 35 patients in the injection group had previously undergone IDET, and 3 had single level fusion but were symptomatic at adjacent levels. Patient selection for either treatment group is not described. No significant difference in demographic characteristics between groups at baseline Mean follow up was 15.5 months in IDET patients and only 7.7 months in injections patients. Conflict of interest: none Page 8 of 23

9 Abbreviations used: IDET, intradiscal electrothermal therapy; LBOS, low back-pain outcome score; ODI, Oswestry Disability Index; RF, radiofrequency; Study details Key efficacy findings Key safety findings Comments Kapural L (2005) 4 Pain Safety outcomes were not reported on. Non randomised controlled trial USA Study period: Not reported Study population: Patients referred for diagnostic discography anticipating future fusion or annuloplasty. Age: 42 years. Sex: 48% male. Two level pain: 52%. Mean duration of symptoms 3.2 years n = 42 (21 IDET) Pain was evaluated by visual analogue scales from 0 (no pain) to 10 (worst possible pain). Baseline 1 year P = IDET 7.4 (±1.9) 1.4 (±1.9) RF 6.6 (±2.0) 4.4 (±2.4) At 3-,6-,9- and 12-month follow-up the pain scores were significantly lower in the IDET group than the RF group Functional ability Assessed using the pain disability index, a scoring system composed of eight subscales covering pain, sexual disability, family and home duties, recreation, occupation, self care, social, and basic life functions. Scored 0 to 80 points (low scores better). Potentially some same IDET patients as included in Appleby (2006) however comparative data reported here. Patients allocated to IDET or RF ablation, in two consecutive cohorts. An experienced operator in both techniques undertook all procedures No significant difference in demographic or clinical characteristics between groups at baseline. Inclusion criteria: Chronic low back pain unresponsive to nonoperative care for 6+ months, no evidence of radiculopathy, no prior surgery, and disc height at least 50% of adjacent levels. Technique: Under local anaesthesia and fluoroscopic guidance IDET via a 17G introducer up to 90 C for 4 minutes vs RF ablation via an introducer needle with electrode placed across the posterior annulus, at up to 65 C for 5 minutes. Follow-up: 12 months median 29% (6/21) of patients treated with RF ablation and 81% (17/21) of patients in the IDET group demonstrated a 60% improvement in pain disability index score. Estimated mean difference in pain disability score (IDET RF ablation) Mean difference (95% p value = CI) Baseline 7.2 (-3.0 to 17.4) weeks (-11.2 to 9.2) months (-27.5 to -7.1) < months (-27.0 to -6.6) year (-32.0 to -11.6) <0.001 Conflict of interest: not reported Page 9 of 23

10 Abbreviations used: IDET, intradiscal electrothermal therapy; LBOS, low back-pain outcome score; ODI, Oswestry Disability Index; RF, radiofrequency; Study details Key efficacy findings Key safety findings Comments Nunley P D (2008) 5 Pain Complications Prospective study. Case series USA Study period: 1999 to 2003 Study population: Low back pain. Age: 42 years. Sex: 70% male. Narcotic medication: 49%. Not working owing to low back pain: 71.7% n = 53 Pain was evaluated by visual analogue scales from 0 (no pain) to 100 (worst possible pain). Mean group scores (variability not described) at 12-month follow-up Baseline 1 year p = IDET A final steady score was seen at a median follow up of 11.2 months, and persisted at that level for subsequent follow up. Functional ability Assessed using the ODI, a 10-item questionnaire scoring from 0% to 100% (low scores better) at 12-month follow-up. A complication occurred in 2% (1/53) of patients (not otherwise described). All patients treated by a single surgeon over a 48 month period. Multivariate analysis showed that patient age and BMI at baseline were not independent predictors of outcome. Inclusion criteria: Low back pain for 6+ months duration unresponsive to conservative treatment, no evidence of radiculopathy, no prior surgery. Mean group scores (variability not described) Baseline 1 year p = IDET Technique: Under local anaesthesia and fluoroscopic guidance IDET via a trocar up to 95 C for 5 minutes. 1 level treatment 38%, 2 levels 58%, 3 levels 4%. At final follow-up of 56 months 6% (3/53) of patients had resumed full work duties, 17% (9/53) were working with only restriction being heavy lifting, 25% (13/53) had resumed light duties, while 53% (28/53) continued not to work. Follow-up: 56 months median Conflict of interest: not reported Medication use The proportion of patients requiring narcotic analgesic medication decreased from 51% at baseline to 13% at 12-month follow-up (measurement of significance not reported) Page 10 of 23

11 Abbreviations used: IDET, intradiscal electrothermal therapy; LBOS, low back-pain outcome score; ODI, Oswestry Disability Index; RF, radiofrequency; Study details Key efficacy findings Key safety findings Comments Orr R D (2005) 6 Complications Case report USA Study period: not reported Study population: Axial low back pain. Age: 45 years. Sex: 100% female. Refractory to conservative care with analgesics and nonsteroidal antiinflammatory drugs, but no physical therapy. Provocative discography showed abnormalities at L5-S1 level. Three catheters were employed during the procedure. On the third attempt adequate positioning was obtained, but the catheter had kinked and during removal the tip broke off inside the disc space. Patient reported that axial back pain was increased by the procedure. At 6 months after the procedure the patient reported left leg paraesthesia and dysaethesia. X ray and CT scan showed migration of the catheter. Electromyography showed a sensory neuropathy affecting the L5 nerve root. However the CT scan showed that the catheter was extradural and unlikely to be the cause of her lower extremity symptoms. Case report of an individual complication. Not clear how many cases have been undertaken at the institution (denominator). Operator experience not described. IDET technique employed is not described. n = 1 Inclusion criteria: not reported. During surgery to remove the catheter a wide laminectomy was undertaken but the catheter was not visible. A longitudinal durotomy was made and the catheter located inside the dural sac having migrated from the disc space, and was removed. Technique: IDET, technique not described. Follow-up: 9 months At 3-month follow-up after removal, the axial back pain remained unchanged, but dysaesthetic symptoms in the left leg had resolved. Conflict of interest: not reported Page 11 of 23

12 Abbreviations used: IDET, intradiscal electrothermal therapy; LBOS, low back-pain outcome score; ODI, Oswestry Disability Index; RF, radiofrequency; Study details Key efficacy findings Key safety findings Comments Scholl B M (2003) 7 Complications After IDET the patient s pain intensified. Case report USA Study period: not reported Study population: low back pain. Age: 36 years. Sex: 100% male. Refractory to conservative care with chiropractic treatment nonsteroidal anti-inflammatory drugs and physical therapy. At 7-month follow-up pain persisted in the mid lumbar region (with no significant lower extremity symptoms), which was managed with narcotic analgesics. Repeat magnetic resonance imaging at 12 months showed an intervertebral decrease in size and signal at the L2 lesion. A small amount of increased T2 signal and enhancement within the subchrondal lesion remained, but diffuse narrow oedema of the L2 vertebral body consistent with osteonecrosis seen at 3-month follow-up had resolved Case report of an individual complication. Not clear how many cases have been undertaken at the institution (denominator). Operator experience not described. Patient initially developed low back pain due to trauma. n = 1 Inclusion criteria: not reported. Technique: IDET, at 90 C for 4 minutes, at L4-L5, and L5-S1, and 5 months later at L2-L3, and L3-L4. Follow-up: 12 months Conflict of interest: none Page 12 of 23

13 Validity and generalisability of the studies The heating protocol used for IDET varied between studies. Some studies included patients treated at one spinal level only, some at multiple levels. Few objective efficacy outcomes are reported. Only one of the studies was randomised and double-blind. Specialist Advisers opinions Specialist advice was sought from consultants who have been nominated or ratified by their Specialist Society or Royal College. The advice received is their individual opinion and does not represent the view of the society. Dr A Cooper (British Pain Society), Mr N Gurusinghe (Society of British Neurological Surgeons), Dr S Ward (British Pain Society). Two of the Specialist Advisers have performed the procedure. Two of the Specialist Advisers consider this to be an established procedure, and one considers it to be novel and of uncertain safety and efficacy. The suggested benefits of the procedure are reduction in pain and analgesic use, improved movement, and functional ability (SF-36 score). The main comparators to this procedure include nucleoplasty, epidural injections, spinal fusion, and prosthetic disc surgery. Adverse events known or reported in the literature include acute post procedural pain, infection and vertebral osteonecrosis. Additional theoretical adverse events may include nerve root injury, bleeding, cerebrospinal fluid leak, catheter breakage, and disc herniation post procedure. The procedure requires experienced interventionist fluoroscopic screening, and cadaveric training should be undertaken. A European registry exists for this procedure. Selection of patients is important. The key efficacy outcomes for this procedure include back pain scores, quality of life and functional status. Page 13 of 23

14 Low back pain due to degenerative disc disease is a very common problem; if it becomes established, IDET will have a significant role. If the procedure is found to be safe and efficacious the advisers thought that the procedure is likely to be offered at specialist interventionist clinics and several district general hospitals. Patient Commentators opinions NICE s Patient and Public Involvement Programme sent questionnaires to 3 trusts for distribution to patients who had the procedure (or their carers). NICE received 0 completed questionnaires. Issues for consideration by IPAC Some potential duplicate reporting of patients, particularly within the metaanalysis. Overlap described where known. All studies included in table 2 of the original overview were summarised within the meta-analysis by Appleby (2006). Page 14 of 23

15 References 1 Appleby D, Andersson G, and Totta M. (2006) Meta-analysis of the efficacy and safety of intradiscal electrothermal therapy (IDET). Pain Medicine 7: Freeman BJC, Fraser RD, Cain CMJ et al. (2005) A randomized, doubleblind, controlled trial: intradiscal electrothermal therapy versus placebo for the treatment of chronic discogenic low back pain... including commentary by Carey TS. Spine 30: Derby R, Eek B, Lee S-H et al. (2004) Comparison of intradiscal restorative injections and intradiscal electrothermal treatment (IDET) in the treatment of low back pain. Pain Physician 7: Kapural L, Hayek S, Malak O et al. (2005) Intradiscal thermal annuloplasty versus intradiscal radiofrequency ablation for the treatment of discogenic pain: a prospective matched control trial. Pain Medicine 6: Nunley PD, Jawahar A, Brandao SM et al. (2008) Intradiscal electrothermal therapy (IDET) for low back pain in worker's compensation patients: can it provide a potential answer? Long-term results. Journal of Spinal Disorders & Techniques 21: Orr RD and Thomas SA. (2005) Intradural migration of broken IDET catheter causing a radiculopathy. Journal of Spinal Disorders & Techniques 18: Scholl BM, Theiss SM, Lopez-Ben R et al. ( ) Vertebral osteonecrosis related to intradiscal electrothermal therapy: a case report. Spine 28:E161-E Appleby D, Andersson G, and Totta M. (2006) Meta-analysis of the efficacy and safety of intradiscal electrothermal therapy (IDET). Pain Medicine 7: Page 15 of 23

16 Appendix A: Additional papers on percutaneous intradiscal electrothermal therapy for low back pain The following table outlines the studies that are considered potentially relevant to the overview but were not included in the main data extraction table (table 2). It is by no means an exhaustive list of potentially relevant studies. Article Bryce DA, Nelson J, Glurich I, et al. (2005) Intradiscal electrothermal annuloplasty therapy: a case series study leading to new considerations WMJ 104 (6): Cohen S P, Larkin T, and Polly Jnr DW et al (2002) A giant herniated disc following intradiscal electrothermal therapy. Journal of spinal disorders & techniques. 15 (6): Ergun R, Sekerci Z, Bulut H, et al. (2008) Intradiscal electrothermal treatment for chronic discogenic low back pain: a prospective outcome study of 39 patients with the Oswestry disability index at 18 month follow-up Neurological Research 30 (4): Fukui S, Iwamoto T,Nosaka S (2006) Lumbar discogenic pain patterns induced by intradiscal heat stimulation Pain Clinic 18 (2): Malik K (2007) Treatment of multilevel degenerative disc disease with intradiscal electrothermal therapy Anaesthesia & Intensive Care 35 (2): Maurer P, Block JE,Squillante D (2008) Intradiscal electrothermal therapy (IDET) provides effective symptom relief in patients with discogenic low back pain Journal of Spinal Disorders & Techniques 21 Number of patients/follow-up n = 51 FU = up to 1 year n = 1 FU = 24 months n = 39 FU = 18 months n = 7 FU = not stated n = 1 FU = 18 months n = 56 FU = 20.5 months Direction of conclusions These data show favorable outcomes after IDET, and suggest that women may experience more improvement than men. Small herniation developed into massive herniation post IDET. Treated by fusion. This procedure may become a middle step step for carefully selected patients who failed non-operative treatment before surgical intervention Referred pain distributions from intervertebral discs in this study resembled distributions of L2 spinal root pain. IDET can be performed at multiple levels at a single sitting Durable clinical improvements can be realised after IDET in highly selected patients with mild disc degeneration Reasons for noninclusion in table 2 Larger studies are included in table 2 Larger studies are included in table 2 Larger studies are included in table 2 Larger studies are included in table 2 Larger studies are included in table 2 Larger studies are included in table 2 Page 16 of 23

17 (1) : McGraw JK, Silber JS (2001) Intradiscal electrothermal therapy for the treatment of discogenic back pain Applied Radiology 30 (7) : n = 30 FU = 2 to 10 months IDET is a relatively safe and effective treatment for patients with chronic discogenic back pain. Larger studies are included in table 2 Park SY, Moon SH, Park MS, et al. (2005) Intradiscal electrothermal treatment for chronic lower back pain patients with internal disc disruption Yonsei Medical Journal 46 (4) : n = 25 FU = 1 to 2 years Of 25 patients 5 underwent fusion within 1 year Larger studies are included in table 2 Studies with longer follow up are included in table 2 Page 17 of 23

18 Appendix B: Related NICE guidance for percutaneous intradiscal electrothermal therapy for low back pain Guidance Interventional procedures Recommendations Non-rigid stabilisation techniques for the treatment of low back pain NICE interventional procedures guidance 183 (2006). 1.1 Limited evidence suggests that non-rigid stabilisation procedures for the treatment of low back pain provide clinical benefit for a proportion of patients with intractable back pain. Current evidence on the safety of these procedures is unclear and involves a variety of different devices and outcome measures. Therefore, these procedures should only be used with special arrangements for consent and for audit or research. 1.2 Clinicians wishing to undertake non-rigid stabilisation techniques for the treatment of low back pain should take the following actions. Inform the clinical governance leads in their Trusts. Ensure that patients understand the uncertainty about the benefits of these procedures and the alternative treatment options, and provide them with clear written information. In addition, use of the Institute s Understanding NICE guidance is recommended Audit and review clinical outcomes of all patients undergoing nonrigid stabilization procedures for the treatment of low back pain. 1.3 Publication of further research will be useful provided that the outcome measures and comparators are well defined. The Institute may review the procedure upon publication of further evidence. Percutaneous intradiscal radiofrequency thermocoagulation for lower back pain NICE interventional procedures guidance 083 (2004). 1.1 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. 1.2 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. Page 18 of 23

19 Audit and review clinical outcomes of all patients having percutaneous intradiscal radiofrequency thermocoagulation for lower back pain. 1.3 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 CURRENT GUIDANCE Percutaneous intradiscal electrothermal therapy for lower back pain. NICE interventional procedures guidance 081 (2004). 1.1 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 1.2 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. 1.3 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. Prosthetic lumbar intervertebral disc replacement NICE interventional procedures guidance 100 () Review in progress. 1.1 Current evidence on the safety and efficacy of prosthetic intervertebral lumbar disc replacement is adequate to support the use of this procedure provided that normal arrangements are in place for clinical governance, consent and audit 1.2 A multidisciplinary team with specialist expertise in the treatment of degenerative spine disease should be involved in patient selection for prosthetic intervertebral lumbar disc replacement. The procedure should only be carried out in patients for whom conservative treatment options have failed or are contraindicated 1.3 The current evidence is based on studies with maximum followup intervals of years. NICE encourages clinicians to continue Page 19 of 23

20 to collect and publish data on longer term outcomes, which should include information about patient selection and the need for reoperation. NICE may review the procedure upon publication of further evidence Laser lumbar discectomy NICE interventional procedures guidance 027 (2003). 1.1 Current evidence on the safety and efficacy of laser lumbar discectomy 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 laser lumbar discectomy should inform the clinical governance leads in their Trusts. They should ensure that patients offered it understand the uncertainty about the procedure s safety and efficacy and should provide them with clear written information. Use of the Institute s Information for the Public is recommended. Clinicians should ensure that appropriate arrangements are in place for audit or research. Publication of safety and efficacy outcomes will be useful in reducing the current uncertainty. NICE is not undertaking further investigation at present Percutaneous endoscopic laser lumbar discectomy NICE interventional procedures guidance XXX (XXXX) in progress 1.1 Current evidence on the safety and efficacy of percutaneous endoscopic laser lumbar discectomy is inadequate in quantity and quality. Therefore this procedure should only be used with special arrangements for clinical governance, consent, and audit or research. 1.2 Clinicians wishing to undertake percutaneous endoscopic laser lumbar discectomy should take the following actions Inform the clinical governance leads in their Trusts Ensure that patients and their carers understand the uncertainty about the procedure s safety and efficacy and provide them with clear written information. In addition, the use of NICE s information for patients ( Understanding NICE guidance ) is recommended Audit and review clinical outcomes of all patients having percutaneous endoscopic laser lumbar discectomy (see section 3.1). 1.3 Surgeons undertaking this procedure should have specific training in the use of lasers and in endoscopy of the spinal canal 1.4 NICE may review the procedure on publication of further evidence Page 20 of 23

21 Technology appraisals Clinical guidelines Public health guidance None applicable None applicable None applicable Page 21 of 23

22 Appendix C: Literature search for percutaneous intradiscal electrothermal therapy for low back pain Database Date searched Version/files No. retrieved Cochrane Database of 16/06/2008 Issue 2, Systematic Reviews CDSR (Cochrane Library) Database of Abstracts of 16/06/ Reviews of Effects DARE (CRD website) HTA database (CRD website) 16/06/ Cochrane Central Database of 16/06/2008 Issue 2, Controlled Trials CENTRAL (Cochrane Library) MEDLINE (Ovid) 16/06/ to June Week MEDLINE In-Process (Ovid) 16/06/2008 June 13, EMBASE (Ovid) 16/06/ to 2008 Week CINAHL (Dialog DataStar, NLH) 16/06/ to date (NAHL) 31 BLIC (Dialog DataStar) 16/06/ Nothing found National Research Register 16/06/ Nothing found (NRR) Archive UK Clinical Research Network 16/06/ Nothing found (UKCRN) Portfolio Database Current Controlled Trials 16/06/ metaregister of Controlled Trials - mrct Clinicaltrials.gov 16/06/ The following search strategy was used to identify papers in MEDLINE. A similar strategy was used to identify papers in other databases. 1 Low Back Pain/ 2 (low$ adj3 back pain$).tw. 3 (chronic$ adj3 back pain$).tw. 4 Intervertebral Disk Displacement/ 5 (Intervertebr$ adj3 (Disk$ or disc$) adj3 Displace$).tw. 6 ((slipped or hernia$ or prolaps$) adj3 (disc$ or disk$)).tw. 7 ((discogenic$ or diskogenic$) adj3 pain$).tw. 8 or/1-7 9 (intradisc$ or intradisk$).tw. 10 Electrocoagulation/ 11 Electric Stimulation Therapy/ 12 Catheter Ablation/ 13 electrotherm$.tw. Page 22 of 23

23 14 (electroannuloplast$ or electroanuloplast$ or anuloplast$ or annuloplast$).tw. 15 thermocoag$.tw. 16 Radio Waves/ 17 (Radiofrequenc$ or radio-frequenc$).tw. 18 RF.tw. 19 or/ and IDET.tw. 22 PIRFT.tw or or and limit 25 to yr=" " 27 Animals/ 28 Humans/ not (27 and 28) not 29 Page 23 of 23