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.2 The trial involved 225 patients diagnosed with cLBP, and each patient was 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 Oswestry Disability Index (ODI) of 30 points (100-point scale) and a minimum visual analog scale (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. Radicular pain was defined as pain that traveled along a dermatomal distribution into the lower extremity, causing pain, numbness, and/or weakness/heaviness of the affected area. Symptomatic spinal stenosis was defined as presence of neurogenic claudication as confirmed by imaging, with symptoms typically including a combination of discomfort, pain, numbness, and weakness in the calves, buttocks, and/or thighs, often brought on by walking or prolonged standing, but relieved by flexion or sitting. 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 average ODI in the treatment arm decreased 20.5 points when compared to the sham arm decrease of 15.2 points (p=0.019). A 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. The authors concluded that patients treated with ablation of the BVN for cLBP showed significantly greater improvement in ODI at 3 months and a higher responder rate when compared to the sham treated control group.
Fischgrund, et al. (2019) then reported the 2-year results from their original clinical trial (SMART Trial).1 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. Therefore, secondary to the high rate of crossover, RF ablation treated patients acted as their own control in a comparison to baseline for the 24-month outcomes. Clinical improvements in the ODI, 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. The mean percent improvements in ODI and VAS compared to baseline at 2 years were 53.7% (p<0.001) and 52.9% (p<0.001), respectively. Responder rates for ODI and VAS were also maintained through 2 years with patients reporting clinically meaningful improvements in both. Using a 10-point improvement in ODI, the commonly accepted minimum clinically important difference (MCID) in the treatment of cLBP, 75.6% of treated patients exhibited a successful response at 3 months. This result was sustained at 24 months with 76.4% of treated patients continuing to receive clinical benefit from BVN ablation. When considering a 20-point threshold for reduction in ODI, 57.5% of treated patients reported clinical benefit at 24 months. At the primary 3-month follow up, 65.4% of patients met or exceeded the VAS MCID of 1.5 cm improvement. The VAS responder rate was sustained at 24 months with 70.2% of patients meeting or exceeding the MCID improvement in VAS.
In 2020, Fischgrund, et al. reported the 5-year outcomes for patients treated with BVN ablation for vertebrogenic cLBP in the SMART randomized control trial (RCT).9 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.
Khalil, et al. (2019) conducted the INTRACEPT Trial, which was a prospective, randomized multicenter study at 20 U.S. sites.5 This RCT compared the effectiveness of intraosseous RF ablation of the BVN to standard of care for the treatment of cLBP in a specific subgroup of patients suspected to have vertebrogenic symptoms. The trial involved 140 patients with cLBP of at least 6 months duration, with Modic Type 1 or 2 vertebral endplate changes between L3 and S1, and who had not responded to at least 6 months of non-operative management. Participants were also required to be skeletally mature, have isolated lumbar pain, have a minimum ODI of 30 points (100-point scale) and a minimum VAS of 4cm (10cm scale). Baseline ODI was 46.1 (p=.064) and VAS was 6.67 (p=.231). Exclusion criteria included: MRI evidence of Modic at levels other than L3-S1, radicular pain, previous lumbar spine surgery, symptomatic spinal stenosis, metabolic bone disease, spine fragility fracture history, trauma/compression fracture, spinal cancer, spine infection, active systemic infection, bleeding diathesis, radiographic evidence of other pain etiology (disc extrusion or protrusion >5mm, spondylolisthesis >2mm at any level, facet arthrosis/effusion correlated with facet-mediated LBP), either ≥3 Waddell’s signs of Inorganic Behavior or Beck Depression Inventory >24, patients receiving injury compensation or involved in litigation, patients currently taking extended-release narcotics with addiction behaviors, BMI >40, bedbound or neurological condition that prevents early mobility or any medical condition that impairs follow up, a contraindication to MRI, allergies to components of the device, or active implantable devices, and pregnancy or lactating. The exclusion criteria of previous lumbar spine surgery did allow an exception for discectomy/laminectomy if performed >6 months before baseline and radicular pain had resolved. Radicular pain was defined as nerve pain that follows a dermatomal distribution and correlates with nerve compression imaging. Symptomatic spinal stenosis was defined as presence of neurogenic claudication as confirmed by imaging. Patients were randomized 1:1 to undergo either RF ablation of the BVN using the Intracept® System or continue standard care, which included, but not limited to, pain medications, physical therapy, exercise, chiropractic treatment, acupuncture, and spinal injections. ODI was reported at baseline, 3, 6, 9, and 12-months post-procedure. Secondary outcome measures included a 10-point VAS for LBP, ODI and VAS responder rates, Short Form (SF-36) and EuroQual Group 5 Dimension 5-Level Quality of Life (EQ-5D-5L) questionnaires. The primary endpoint was a comparison between the treatment arm and standard care arm of the mean change in ODI from baseline to 3 months post-treatment. The interim analysis demonstrated a clear statistical superiority (p<.001) for all primary and secondary patient-reported outcome measures in the RF ablation arm compared with the standard care arm; therefore, participants were offered early cross-over to the control arm. 3-month results between the RF ablation arm and the standard care arm showed the mean changes in ODI were -25.3 points versus -4.4 points, respectively; an adjusted difference of 20.9 points (p<0.001). Mean changes in VAS were -3.46 versus -1.02, respectively; an adjusted difference of 2.44 cm (p<0.001). 74.5% of patients achieved a ≥10-point improvement in ODI in the RF ablation arm, compared with 32.7% in the standard care arm (p<0.001). The authors concluded that minimally invasive RF ablation of the BVN for chronic vertebrogenic LBP resulted in significant improvement of pain and function at 3 months.
Smuck, et al. (2021) published the 12-month results from the INTRACEPT Trial.10 Participants were followed up at 6 weeks, 3, 6, 9, and 12 months. Standard care patients were re-baselined and followed up for 6 months after BVN ablation. The primary endpoint was the comparison between the BVN ablation and standard care arms of mean ODI change from baseline. Secondary endpoints were VAS, SF-36, EQ-5D-5L, responder rates, and rates of continued opioid use. At the time of the interim analysis at 3 months, 140 participants were randomized. Results showed that BVN ablation (n=66) was superior to standard care (n=74) at 3 months for the primary endpoint (mean ODI reduction, difference between arms of −20.3 (CI −25.9 to −14.7 points; p<0.001)), VAS pain improvement (difference of −2.5 cm between arms (CI −3.37 to −1.64, p<0.001)) and quality of life outcomes. At 12 months, BVN ablation demonstrated a 25.7±18.5-point reduction in mean ODI (p<0.001), and a 3.8±2.7 cm VAS reduction (p<0.001) from baseline, with 64% demonstrating ≥50% reduction and 29% pain free. The former standard care arm patients who elected BVN ablation (92%) showed a 25.9±15.5 point mean ODI reduction (p<0.001) from baseline. The proportion of opioid use did not change in either group (p=0.56). Seventy-four per cent (74%) of BVN ablation arm patients reported improvement of their condition at 12 months; 75% indicating treatment success. Similar satisfaction (78% improvement, 72% success) was reported 6 months post BVN ablation for participants who formerly underwent standard care. No serious device-related adverse events were reported.
Twenty-four (24) month treatment arm results for the INTRACEPT Trial were published by Koreckij, et al (2021).11 Baseline characteristics for the 58 BVN ablation patients completing a 24-month visit showed that 67% had back pain for > 5 years, 36% were taking opioids at baseline, 50% had prior epidural steroid injections, and 12% had prior low back surgery. At 24 months, ODI and VAS improved 28.5 ± 16.2 points (from baseline 44.5; p< 0.001) and 4.1 ± 2.7 cm (from baseline 6.6; p< 0.001), respectively. A combined responder rate of ODI ≥ 15 and VAS ≥ 2 was 73.7%. A ≥ 50% reduction in pain was reported in 72.4% of patients and 31% reported being pain-free at 2 years. At 24 months, 62% fewer patients were actively taking opioids. No serious device or device-procedure related adverse events were reported by the authors through 24 months.
A prospective, single-arm, open-label study to evaluate the effectiveness of intraosseous BVN RF ablation for the treatment of vertebrogenic-related cLBP in a typical spine practice setting was conducted by Truumees, et al. (2019).12 The authors sought to employ more permissive criteria for study inclusion than that used in the SMART Trial1,2,9, such as patients who had prior discectomy and those who took extended-release narcotics. Consecutive patients with cLBP of at least 6 months duration, at least 6 months of conservative care, 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 4 vertebral bodies. The primary endpoint was patient-reported change in ODI from baseline to 3 months post-BVN ablation. Secondary outcome measures included change in VAS, SF-36, EQ-5D-5L, and responder rates.
An interim analysis was conducted and reported when the first 28 patients treated reached their 3-month post procedure visit. Baseline ODI was 48.5; VAS was 6.36 cm. Seventy-five percent (75%) of the study patients reported LBP symptoms for ≥ 5 years; 25% were actively using opioids; and 61% were previously treated with injections. Mean change in ODI at 3 months post-BVN ablation was -30.07+14.52 points (p< 0.0001); mean change in VAS was -3.50+2.33 (p<0.0001). Ninety-three percent (93%) of patients achieved a ≥10-point improvement in ODI, and 75% reported ≥20-point improvement. The authors concluded that minimally invasive RF ablation of the BVN demonstrated a significant improvement in pain and function in this population of real-world patients with cLBP of a vertebrogenic origin.
Macadaeg, et al. (2020) reported the 12-month results for all patients enrolled and treated with BVN ablation the clinical trial first reported by Truumees, et al.13 Forty-eight (48) patients from community spine and pain practices were treated with BVN ablation. Patients were followed post procedure for 12 months using ODI, VAS, EQ-5D-5L, and SF-36 patient reported outcome metrics. Results showed that 47 patients successfully received BVN ablation, and 45 patients completed 12 months of follow up. 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 >69% reported a 50% reduction in VAS pain scale. SF-36 and EQ-5D-5L scores improved 26.27 ± 17.19 and 0.22 ± 0.15, respectively (each p< 0.001). The authors concluded that this data supports the clinical effectiveness of BVN ablation in the community practice setting.
A systematic review of the published literature on the efficacy, effectiveness, and complications associated with BVN ablation for the treatment of cLBP was published by Conger, et al. (2021).14 Evidence was evaluated using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) system of appraisal to determine the quality of the evidence of the effectiveness of intraosseous BVN radiofrequency neurotomy (RFN). According to GRADE, there is 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.
Additional reviews3,4,15 are supportive of BVN ablation as an effective treatment and more beneficial than current standard of care for a subset of patients with cLBP based on moderate-quality evidence.
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 Pain16 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.” 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.23 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.