11. Long-term outcomes following intraosseous basivertebral nerve ablation for the treatment of chronic low back pain: five-year treatment results from a prospective randomized double-blind sham-controlled multicenter study

Abstract

BACKGROUND CONTEXT Current literature suggests that degenerated or damaged vertebral endplates are a significant cause of vertebrogenic chronic low back pain (CLBP). Modic changes are one objective MRI biomarker for this specific subset of patients. Intraosseous basivertebral nerve (BVN) ablation, using radiofrequency energy under image guidance, was compared to a sham control in a randomized controlled trial (RCT) and demonstrated superiority at 12 months. Two-year data from the treatment arm of this RCT showed maintenance of clinical improvements at 2 years following ablation of the BVN. PURPOSE This study reports the 5-year clinical outcomes in this cohort of patients. STUDY DESIGN/SETTING Prospective, open label, single arm five-year follow-up of the SMART RCT. The primary requirements for inclusion in the original RCT were CLBP with a duration greater than 6 months; CLBP nonresponsive to at least 6 months of nonsurgical management; and Modic Type 1 or 2 changes at the vertebral endplates of the levels targeted for treatment. BVN ablation was performed under image guidance in an outpatient setting for those patients randomized to the treatment arm. PATIENT SAMPLE This five-year follow-up study was conducted in the U.S. at the 13 study sites that treated patients in the original RCT. In the US BVN ablation arm, 117 patients were successfully treated and targeted, and comprise the per protocol (PP) population for this study. OUTCOME MEASURES Patient-reported outcomes of Oswestry Disability Index (ODI), visual analog score (VAS), responder rates, postablation treatments, and patient satisfaction were collected. The primary outcome was mean change in ODI from baseline. Comparisons between the postablation and baseline values were performed using a paired t-test at the 0.05 level of significance. METHODS A single telephonic study visit was conducted by an independent research nurse between June 2019 to November 2019 (a minimum of 5 years post-BVN ablation). Self-reported patient outcomes were collected via interview using validated questionnaires that were sent in advance of the visit. No additional interventions were required in the 5-year+ follow-up study. RESULTS One hundred of the 117 US treated patients (retention rate 85%) were available for review with a mean follow-up of 6.4 years (range 5.4 to 7.8 years). Mean ODI score significantly improved from 42.81 to 16.86 at 5 years of follow-up, a reduction of 25.95 points (p 50% reduction in pain, 47% reported a >75% reduction in pain, and 34% reported complete pain resolution. Responder rates were maintained at five years with 75% of patients exceeding a combined threshold of ≥15-point ODI and ≥2-point VAS for function and pain improvement, and 65% reporting they had returned to their pre– low back pain activity level. CONCLUSIONS CLBP patients treated with BVN ablation exhibit sustained clinical improvements in function and pain with high responder rates at a mean of 6.4 years following treatment. BVN ablation appears to be a durable, minimally invasive treatment for the relief of vertebrogenic CLBP. FDA DEVICE/DRUG STATUS Intracept procedure (Approved for this indication).