# A Superiority Trial of Radiofrequency Ablation for Low Back Pain

> **NIH NIH U01** · UNIVERSITY OF WASHINGTON · 2024 · $1,364,600

## Abstract

Low back pain is the #1 contributor to years lived with disability (CLBP; pain persisting for ≥3 months). An
obstacle to reducing the societal burden of CLBP is that most treatments have only small effects (~5-10%
improvements in functional limitations and pain) when compared to a control treatment.
 Lumbar radiofrequency ablation (LRFA) is a minimally invasive procedure that is widely performed for
CLBP. It can be used in patients for whom CLBP is isolated to the lumbar facet joints, defined by pain relief
(“positive responses”) after local anesthetic medial branch blocks (MBBs) to the medial branch nerves. LRFA
applies a thermal lesion to these nerves, temporarily reducing or eliminating CLBP. Unlike most CLBP
treatments, LRFA can result in large improvements in properly selected patients. However, LRFA is
neurodestructive, has potential adverse effects, and there is conflicting evidence regarding its effectiveness as
seen in randomized controlled trials (RCTs). Experts have noted that those RCTs showing no effects of LRFA
may be explained by (1) poor LRFA technique insufficient to adequately lesion the medial branches, and (2)
suboptimal clinical selection criteria for identifying LRFA candidates.
 The most stringent evidence-based guidelines for LRFA technique and patient selection are those of the
Spine Intervention Society (SIS). The SIS guidelines mandate various aspects of technique to optimize medial
branch lesioning and consequent improvements in CLBP. They also include stringent clinical screening criteria
for determining appropriate LRFA candidates, such as requiring ≥80% pain improvement to define positive
MBB responses, and 2 separate sets of comparative MBBs with low anesthetic volume (<0.5cc).
 A definitive RCT of LRFA vs. control has yet to be conducted. Despite this, LRFA using conventional
electrodes (LRFA-C) and new technological modifications to LRFA are now commonly used. These
modifications are intended to make the procedure easier to perform and faster than LRFA-C. Among these
modifications, LRFA using multi-tined electrodes (LRFA-M) has shown the greatest promise. However,
there are no RCTs examining whether LRFA-M improves clinical outcomes compared to a simulated LRFA
control procedure, or whether it is actually easier or faster to perform than LRFA-C.
 We propose A Superiority Trial of Lumbar Radiofrequency Ablation for Low back pain, or “ASTRAL”: a
definitive, double-blind, 3-arm, multicenter trial to examine the effectiveness of LRFA-C and LRFA-M,
each compared to a simulated ablation control procedure (simulated LRFA). ASTRAL will use the SIS criteria
for LRFA technique and patient selection. Aim 1 is to compare the effectiveness of LRFA-C with simulated
LRFA for improving back-related functional limitations. Aim 2 is to compare the effectiveness of LRFA-M with
simulated LRFA for improving back-related functional limitations. Secondary aims will compare LRFA-C and
LRFA-M with regards to procedure duration, radiation...

## Key facts

- **NIH application ID:** 10977408
- **Project number:** 1U01AR084723-01
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **Principal Investigator:** Janna L Friedly
- **Activity code:** U01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $1,364,600
- **Award type:** 1
- **Project period:** 2024-09-04 → 2029-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10977408

## Citation

> US National Institutes of Health, RePORTER application 10977408, A Superiority Trial of Radiofrequency Ablation for Low Back Pain (1U01AR084723-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10977408. Licensed CC0.

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