Post-procedure MRI lesion size after 7-min basivertebral nerve ablation

Background Chronic vertebrogenic low back pain can be successfully treated with basivertebral nerve ablation (BVNA). Initial studies reported the effectiveness of BVNA using a 15-min ablation protocol. Recently, industry has sponsored adopting 7-min ablations for appropriately placed probes. The effectiveness of 7-min ablations has been called into question. For 15-min ablations, lesion size has been reported to be approximately 1 cm in diameter. There are no literature reporting lesion sizes for 7-min ablations. Objective The purpose of this study was to evaluate MRI lesion size for patients who underwent 7-min BVNA. Methods A retrospective cohort study was conducted of patients who underwent BVNA and had post-procedure MRI available for review. All MRIs were obtained for patients who failed to improve after BVNA or developed new symptoms. On the sagittal post-procedure MRI, the BVNA lesion height and width size were measured by two independent reviewers. Interobserver reproducibility was assessed using intraclass correlations and Bland-Altmann analysis. The average height and width of the lesion was calculated with standard deviations. Results A total of 10 out of 57 patients who underwent BVNA during the study timeframe had post-procedure MRI. There was acceptable reproducibility between MRI reviewers. The average lesion height size was 11.6 mm (±1.2 mm), and the average width was 10.9 mm (±1.4 mm). Conclusions Our study demonstrated that patients who received an MRI due to treatment failure or new symptoms after treatment with 7-min BVNA had average height and width lesion sizes of approximately 1.1 cm. This is within range of the lesion size of historically accepted 15-min BVNA lesion sizes.