Evaluating the effectiveness of 7-min basivertebral nerve ablation in treating vertebrogenic low back pain

Basivertebral nerve radiofrequency ablations (BVNRFA) is an established treatment for chronic vertebrogenic low back pain. However, published studies have exclusively evaluated the effectiveness of 15-min ablations for BVNRFA. Recently, industry has recommended performing 7-min ablations but there is no literature demonstrating this as an effective procedure.

The purpose of this study was to evaluate 7-min BVNRFA outcomes of pain and function.

Retrospective review of consecutive patients with chronic (>6 months) axial midline low back pain with a reported pain score ≥4 that had failed conservative treatment with corroborating Modic type I or Modic type II changes on MRI who underwent exclusively 7-min BVNRFA was conducted at a multidisciplinary spine center. Visual analog pain scores (VAS) were collected at baseline, 1-, 3-, 6-, and 12-month post-procedure. Consistent with prior literature, success was defined two ways: achieving a ≥50 % in VAS pain reduction at post-procedure visits compared to baseline scores and achieving a reduction of VAS greater than the minimally clinical important difference of 2. Wilcoxon signed-rank test was used to compare post-procedure scores with baseline scores. Percent of patients with a successful treatment was calculated at each follow-up time period.

A total of 86 patients underwent BVNRFA during the study period and 75 met inclusion criteria. VAS scores significantly improved between baseline (7.1 ± 1.9) and 1-month (3.9 ± 3.0, p < 0.001), 3-months (3.4 ± 3.0, p < 0.001), 6-months (4.4 ± 2.6; p < 0.001) and 12-months post-procedure scores (3.7 ± 2.6; p < 0.001). The percentage of patients with a successful treatment of ≥50 % in VAS pain reduction was 50.7 % (95 % CI 38.8 %, 26.7 %) at 1-month, 56.9 % (95 % CI 44.9 %, 69.0 %) at 3-months, 42.9 % (95 % CI 29.0 %, 56.7 %) at 6-months and 50.0 % (95 % CI 23.1 %, 67.9 %) at 12-months. The percentage of patients with a successful treatment of ≥2 in VAS pain reduction was 67.2 % (95 % CI: 55.9 %, 78.4 %) at 1-month, 67.7 % (95 % CI: 56.3 %, 79.1 %) at 3-months, 65.3 % (95 % CI: 52.0 %, 78.6 %) at 6-months and 70.0 %, (95 % CI: 52.1 %, 90.8 %) at 12-months.

Although our study demonstrated that patients treated with BVNRFA with a 7-min ablation reported significant improvement in pain, the proportion of patients with a successful reduction of pain is likely lower than data published for 15-min ablations. Future controlled trials comparing outcomes and lesion sizes of 7- and 15-min BVNA are needed.