NCT07222462 · University of Washington
A Superiority Trial of Radiofrequency Ablation for Low Back Pain
(ASTRAL)
What this study is about
The purpose of the ASTRAL Study is to evaluate the effectiveness of LRFA (Lumbar radiofrequency ablation) against a control procedure.
View original scientific description
The purpose of the ASTRAL Study is to evaluate the effectiveness of LRFA (Lumbar radiofrequency ablation) against a control procedure. The ASTRAL Study will enroll individuals with chronic low back pain (CLBP) and randomly assign them to one of three groups: lumbar radiofrequency ablation using conventional electrodes placed parallel to the medial branch nerves (LRFA-C), lumbar radiofrequency ablation using multi-tined electrodes placed perpendicular to the medial branch nerves (LRFA-M), or a simulated radiofrequency ablation procedure.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Age ≥18 years
- CLBP of duration ≥ 3 months. Low back pain is defined as occurring between the lower posterior margin of the rib cage and the horizontal gluteal fold.
- Low back pain intensity numerical rating scale (NRS) ≥ 4 with one of the following prior to LRFA: 1) Current low back pain intensity, 2) Average pain over past 7 days, OR 3) Pain intensity without specification of recall period
- Has had conservative treatments for CLBP (physical therapy, exercise therapy, spinal manipulation, massage, acupuncture, etc.)
- Candidate for unilateral LRFA (L1-S1 joints; ≤3 levels); or bilateral LRFA (L1-S1 joints; ≤2 levels)
- 'Positive responses' (≥80% improvement of CLBP pain intensity) to 2 sets of anesthetic-only MBBs (≤0.5cc of local anesthetic)
- Able to read, speak, and understand English sufficient for informed consent purposes
- Stated willingness to comply with all study processes and availability for the duration of the study, and provision of a signed and dated informed consent form
Exclusion criteria
- CLBP attributed primarily to specific spine-related conditions (radiculopathy, lumbar spinal stenosis, spinal instability), 'red flag' conditions (infection / malignancy / fracture), and/or inflammatory arthritis (RA, SpA, etc.)
- Prior lumbar facet joint (intra-articular or medial branch nerve) corticosteroid injections (past 6 months)
- Surgery involving one or more of spinal levels where LRFA is to be performed, in the past 2 years
- Lumbar fusion involving the spinal levels where LRFA is considered, at any time
- Prior known severe lumbar central canal stenosis on MRI as defined by Lee (2011): obliteration of the cerebrospinal fluid (CSF), and marked compression of dural sac, and none of the cauda equina can be visually separated from each other. No new MRIs would be done specifically as part of the study processes.
- Prior formal diagnosis of fibromyalgia by a rheumatologist (diagnosis by primary care physician or pain medicine specialist is not sufficient)
- Unstable psychiatric or terminal medical conditions that would limit study participation and the likelihood of follow-up for 12 months post-randomization
- Pregnancy, being a prisoner, or having a prior formal diagnosis of cognitive impairment by a neuropsychologist or neurologist, confirmed by health record documentation
- Participant report of prior formal diagnosis of cognitive impairment by a neuropsychologist or neurologist can be obtained, but participant-reported cognitive impairment by a neuropsychologist or neurologist must be confirmed via health record documentation. No new evaluations for cognitive impairment would be done specifically as part of the study processes.
- Contraindication to local anesthetic, corticosteroid, or any aspects of LRFA
- Cannot reach MBB targets with 11.9cm needle
- Major planned life events over the next 4 months that might interfere with study participation (e.g., major abdominal or chest surgery or extended vacation)
Where
- Atlanta, Georgia
- Cleveland, Ohio
- Salt Lake City, Utah
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Feb 9, 2026 · Source of record for eligibility and locations