A systematic review of the published literature on the efficacy, effectiveness, and complications associated with BVN ablation for the treatment of chronic low back pain (cLBP) was published by Conger, et al. (2021).1 Evidence was evaluated using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) system of appraisal to determine the certainty of the evidence of the effectiveness of intraosseous BVN radiofrequency neurotomy (RFN). The reviewers found moderate-quality evidence that BVN RFN is both an effective treatment compared to sham procedure and superior to continued standard care management for reduction of pain and disability in stringently selected patients with cLBP and corresponding Modic type 1 and 2 changes at a minimum of 3 months.
Khalil, et al. (2019), conducted a multicentered RCT that compared the effectiveness of intraosseous radiofrequency (RF) ablation of the BVN to standard care for the treatment of cLBP in a specific subgroup of patients suspected to have vertebrogenic-related symptomatology.8 A total of 140 patients (mean age 50 years) with CLBP of at least 6 months duration, with Modic Type 1 or 2 vertebral endplate changes between L3 and S1, were randomized to undergo either RF ablation of the BVN or continue standard care. Oswestry disability index scores (ODI) were collected at baseline, 3, 6, 9 and 12-months post-procedure. Secondary outcome measures included the visual analog scale (VAS) for pain intensity and responder rates, and quality of life measures (SF-36 and EQ-5D-5L). The primary endpoint was a between-arm comparison of the mean change in ODI from baseline to 3 months post-treatment. At 3 months follow-up, the minimally invasive RF ablation group demonstrated clinically significant improvement of pain and function compared to the standard care group. Treatment success was significantly greater in the RF group (74.5%) compared with patients in the standard care arm (32.7%) [p<.001].
Health-related quality of life outcomes showed a statistically significant difference favoring the RF group. The study was stopped for benefit at 3 months, which followed an interim analysis showing superiority of the intervention arm. This resulted in a high rate of cross-over. Study limitations include the use of a nonstructured standard care control, open label design, and short-term results. In addition, industry funding was a potential source of study bias.
Fischgrund, et al. (2018) conducted a prospective randomized double-blind sham-controlled clinical trial that evaluated the safety and efficacy of radiofrequency (RF) ablation of the BVN for treatment of cLBP.3 The trial involved 225 patients with a mean age of 47 years who were diagnosed with cLBP. Participants were randomized to either a sham (78) or treatment intervention (147). Treatment arm patients underwent thermal ablation at the terminus of the BVN using the Intracept® System. Skeletally mature patients with chronic (≥ 6 months), isolated lumbar pain, who had not responded to at least 6 months of non-operative management, and had Type 1 or Type 2 Modic changes at 3 or less contiguous levels at L3-S1 on MRI were included in the study. Furthermore, patients were required to have a minimum ODI of 30 points (100-point scale) and a minimum VAS of 4cm (10cm scale). Mean baseline ODI was 42 and mean baseline VAS was 6.7cm. Stringent exclusion criteria were applied, which included: radicular pain, previous lumbar spine surgery, symptomatic spinal stenosis, diagnosed osteoporosis (T<2.5), disc extrusion or protrusion >5mm, spondylolisthesis >2mm at any level, ≥3 Waddell’s signs of Inorganic Behavior, Beck Depression Inventory >24, patients involved in litigation related to back pain or injury, patients receiving disability compensation, and patients currently taking extended-release narcotics. Patients were evaluated at baseline, and at 2 weeks, 6 weeks, and 3, 6, and 12 months post procedure. The primary endpoint was the comparative change in ODI at 3 months. Results showed the mean between group difference was 5.3 points favoring the intervention group. This difference was not clinically significant; however, the responder analysis, based on ODI decrease ≥ 10 points, showed that 75.6% of patients in the treatment arm as compared to 55.3% in the sham control arm exhibited a clinically meaningful improvement at 3 months.
Fischgrund, et al. (2019) subsequently reported the 2-year results from their original clinical trial (SMART Trial).4 Originally, patient evaluations, including patient self -assessments, physical and neurological examinations, and safety assessments, were performed out to 12 months. The protocol was subsequently modified to include longer-term follow up to 24 months. Sham control arm patients were also allowed to cross to RF ablation at 12 months. Of the 78 patients in the control arm, 57 (73%) elected to cross over to receive the Intracept® treatment. Overall, 106 participants, who received BVN ablation, were included in the 24-month analysis. Participants exhibited a durable ODI mean improvement (23.4 points) at 24 months compared to the mean improvements observed during their first year of follow up (20.3, 20.8, and 19.8 points at 3, 6, and 12 months, respectively). At 24 months, the previously reported treatment success (75.6% at 3 months) result was sustained with 76.4% of treated patients continuing to receive clinical benefit from BVN ablation. Improvements in the VAS, and the Medical Outcomes Trust Short-Form Health Survey Physical Component Summary were statistically significant compared to baseline at all follow-up time points through 2 years.
In 2020, Fischgrund, et al. reported the 5-year outcomes for 100 patients treated with BVN ablation for vertebrogenic cLBP in the SMART randomized control trial (RCT).5 Five-year study results following BVN ablation showed a significant mean reduction in ODI of 25.95 ± 18.54 (60.6%) compared to a baseline of 42.81 (p<0.001). Mean reduction in VAS pain score was 4.38 points (baseline of 6.74, p<0.001). In total, 66% of patients reported a > 50% reduction in pain, 47% reported a > 75% reduction in pain, and 34% of patients reported complete resolution of their pain. Composite responder rate using thresholds of ≥ 15-point ODI and ≥ 2-point VAS for function and pain at 5 years was 75%. Patients reported a high degree of patient satisfaction: 70% rated their condition as improved; 27% reported no change; and 3% reported their condition had worsened. Seventy-nine percent (79%) of patients indicated they would repeat the BVN ablation for the same condition, and 65% reported resumption of their level of activity prior to having low back pain.
A prospective, single-arm study performed by Truumees, et al. (2019), observed the effects of intraosseous RF ablation of the BVN for the treatment of vertebrogenic-related CLBP.19 Patients with cLBP of at least 6 months duration and with Modic Type 1 or 2 vertebral endplate changes between L3 and S1 were treated with RF ablation of the BVN in up to four vertebral bodies. Ninety-three percent (93%) of patients achieved a ≥10-point improvement in ODI, and 75% reported ≥20-point improvement. They concluded that minimally invasive RF ablation of the BVN results in a significant improvement in pain and function in this population of real-world patients with chronic vertebrogenic-related LBP.
Markman, et al. (2020) evaluated the hypothesis that cLBP patients reporting reduced opioid use have superior functional outcomes following BVN radiofrequency ablation.14 Data were obtained from 225 patients enrolled in a 2:1, randomized, sham-controlled, double-blind trial examining the effects of BVN ablation on cLBP. Patients who demonstrated Modic Type 1 or 2 vertebral endplate changes in one or more L3 to S1 segments, and were nonresponsive to a minimum of 6 months of nonsurgical treatment were included in the study. The authors concluded that subjects undergoing BVN ablation reported lower opioid use and had greater improvement in ODI and VAS scores. This post hoc analysis has several limitations including the small subgroup sample size (N=77), the self-reported use of opioids (potential for recall bias), and the exclusion of patients receiving long-acting opioid therapy (potential selection bias).
Macadaeg, et al. (2020) conducted a prospective, single arm trial including 48 patients with more than 6 months of CLBP and Type 1 or 2 Modic changes on MRI.13 Patients were followed post-procedure for 12 months using ODI, VAS, EQ-5D-5L and SF-36 patient-reported outcome metrics. Mean reduction in ODI at 12 months was 32.31 +/- 14.07 (p < 0.001) with 88.89% (40/45) patients reporting a ≥ 15 point ODI decrease at 12 months. Mean VAS pain score decrease was 4.31+/-2.51 at 12 months (p < 0.001) and more than 69% reported a 50% reduction in VAS pain scale. Similarly, SF-36 and EQ-5D-5L scores improved 26.27+/-17.19 and 0.22+/-0.15 (each p < 0.001). Limitations include the observational, open label design, relatively small sample size, uncertainty about generalizability, and the risk of bias associated with industry sponsorship.
Transforaminal epiduroscopic basivertebral nerve laser ablation was studied by Kim, et al, (2018) who presented a cohort of 14 patients with cLBP greater than 6 months which was unresponsive to at least 4 months of conservative care.9 This cohort included patients with MRI findings of Modic Type 1 or 2 changes and positive confirmatory provocation discography to determine the affected levels. The results of this preliminary, single-arm case series were promising, yet the role of the transforaminal epiduroscopic ablation remains to be further investigated.
The International Society for the Advancement of Spine Surgery (ISASS) 2020 guideline – Intraosseous Ablation of the Basivertebral Nerve for the Relief of Chronic Low Back Pain concluded that “The procedure is supported by level 1 evidence including 2 RCTs demonstrating a statistically significant decrease in pain and an improvement in function with outcomes sustained to at least 24 months in a limited number of studies.”11 BVN ablation may be indicated as a treatment option for cLBP for patients that fail nonsurgical treatment and their cLBP is diagnosed using well-established clinical and MRI findings.
The American Society of Pain and Neuroscience (ASPN) identified evidence-based guidelines from the available literature for the proper identification and selection of patients with vertebrogenic low back pain for BVN ablation.17 The systematic review was conducted using United States Preventive Services Task Force Criteria Modified for Interventional Spine Procedures and assigned a Grade A rating of the quality of evidence for BVN ablation indicating a high certainty that the net benefit is substantial in appropriately selected individuals.
The North American Spine Society (NASS)16 position statement defines appropriate coverage of BVN ablation. BVN is indicated when:
- Patients are skeletally mature and have CLBP for at least 6 months, and lower back pain is their main symptom.
- Patients have failed to adequately improve despite attempts at nonsurgical management.
- Patients have Type 1 or Type 2 Modic changes on MRI — endplate hypo-intensity (Type 1) or hyperintensity (Type 2) on T1 images plus hyperintensity on T2 images (Type 1) involving in the endplates between L3 and S1.
BVN ablation is NOT indicated in ANY of the following scenarios:
- Evidence on imaging (MRI, flexion/extension radiographs, etc.) suggests another obvious etiology for the patient’s LBP symptoms, including but not limited to lumbar stenosis, spondylolisthesis, segmental instability, disc herniation, degenerative scoliosis or facet arthropathy or effusion with clinically suspected facet joint pain.
- Metabolic bone disease (e.g., osteoporosis), treatment of spine fragility fracture, trauma/compression fracture or spinal cancer.
- Spine infection or active systemic infection.
- Neurogenic claudication, lumbar radiculopathy or radicular pain due to neuro-compression (e.g., HNP, stenosis), as primary symptoms.
- Patients with severe cardiac or pulmonary compromise.
- Patients with implantable pulse generators (e.g., pacemakers, defibrillators) or other electronic implants unless specific precautions are taken to maintain patient safety.