A Superiority Trial of Radiofrequency Ablation for Low Back Pain

NCT ID: NCT07222462

Last Updated: 2025-12-24

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

NA

Total Enrollment

300 participants

Study Classification

INTERVENTIONAL

Study Start Date

2026-01-31

Study Completion Date

2029-08-31

Brief Summary

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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.

Detailed Description

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Low back pain is the #1 contributor to years lived with disability in the United States. Lumbar radiofrequency ablation (LRFA) is a minimally invasive procedure for chronic low back pain (CLBP) commonly used in the US, but the effectiveness of this procedure has yet to be fully explored, and a definitive, double-blind, multicenter RCT demonstrating a clinically relevant benefit of LRFA over a control procedure has yet to be conducted. LRFA-C involves placing a conventional radiofrequency electrode parallel to each targeted medial branch nerve, administering local anesthetic, and confirming placement with nerve stimulation as per standard clinical practice. LRFA-M follows the same processes as LRFA-C, albeit a multi-tined radiofrequency electrode will be used to create larger lesions, and the electrode will be positioned perpendicular to the medial branch nerve. The primary objectives of ASTRAL are to 1) compare the effectiveness of LRFA-C with a simulated LRFA control procedure for improving back-related functional limitations, and 2) compare the effectiveness of LRFA-M with a simulated LRFA control procedure for improving back-related functional limitations. The ASTRAL Study also aims to explore the difference in effectiveness, procedure duration, radiation dosage, and pain intensity between LRFA-C and LRFA-M.

Conditions

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Chronic Low Back Pain (CLBP)

Keywords

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lumbar radiofrequency ablation (LRFA) corticosteroid injections

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

TREATMENT

Blinding Strategy

TRIPLE

Participants Investigators Outcome Assessors

Study Groups

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LRFA-C

Lumbar radiofrequency ablation with conventional electrodes

Group Type ACTIVE_COMPARATOR

Lumbar radiofrequency ablation with conventional electrodes (LRFA-C)

Intervention Type PROCEDURE

LRFA-C positions a conventional thermal radiofrequency electrode at each medial branch nerve to be ablated and administers local anesthetic to the nerve. Parallel placement of the electrode will be achieved. Once the electrode is in correct position and nerve stimulation testing done, a radiofrequency lesion is generated, achieving a temperature 80°C-90°C, lasting 90-120 seconds. If a 16-gauge or larger electrode is used, no second lesion needs to be made. If an 18-gauge electrode is used, the electrode will be repositioned slightly by withdrawing or repositioning parallel to the 1st ablation site, or by rotating the electrode, and a 2nd lesion made. Local corticosteroid injection is then performed at the ablation site at a total corticosteroid equivalent of 80mg triamcinolone, divided equally among the medial branches targeted; this dose can be reduced as needed according to the medical status of each patient. This process is applied for each medial branch nerve targeted.

LRFA-M

Lumbar radiofrequency ablation with multi-tined electrodes

Group Type ACTIVE_COMPARATOR

Lumbar radiofrequency ablation with multi-tined electrodes (LRFA-M)

Intervention Type PROCEDURE

LRFA-M positions a multi-tined thermal radiofrequency electrode at each medial branch nerve to be ablated and administers local anesthetic to the nerve. However, the multi-tined thermal radiofrequency electrode is thought to achieve larger lesions and thus does not require parallel electrode placement; the LRFA-M electrode will be placed perpendicular to the medial branch nerve. All subsequent processes are the same as for LRFA-C. This includes local corticosteroid injection at each ablation site at a total corticosteroid equivalent of 80mg triamcinolone, divided equally among the medial branches targeted; this dose can be reduced as needed according to the medical status of each patient. This process is applied for each medial branch nerve targeted.

Simulated LRFA

Simulated lumbar radiofrequency ablation

Group Type SHAM_COMPARATOR

Simulated lumbar radiofrequency ablation

Intervention Type PROCEDURE

The simulated LRFA control procedure will be performed in an identical fashion to LRFA-M, except 1) after electrode positioning, a neurodestructive lesion will not be made; and 2) a pre-recorded audio recording of the procedure will be played (out of view of the patient, immediately adjacent to the RFA machine) in order to simulate the beeping and other sounds of the machine and to ensure the appropriate length of the simulated procedure. The electrode will remain in place for the 90-120 seconds that lesioning would normally take, but without heat application. The electrode will then be repositioned to simulate a second lesion, also of duration 90-120 seconds. Local corticosteroid injection is then performed at the ablation site at a total corticosteroid equivalent of 80mg triamcinolone, divided equally among the medial branches targeted; this dose can be reduced as needed according to the medical status of each patient. This process is applied for each medial branch nerve targeted.

Interventions

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Lumbar radiofrequency ablation with conventional electrodes (LRFA-C)

LRFA-C positions a conventional thermal radiofrequency electrode at each medial branch nerve to be ablated and administers local anesthetic to the nerve. Parallel placement of the electrode will be achieved. Once the electrode is in correct position and nerve stimulation testing done, a radiofrequency lesion is generated, achieving a temperature 80°C-90°C, lasting 90-120 seconds. If a 16-gauge or larger electrode is used, no second lesion needs to be made. If an 18-gauge electrode is used, the electrode will be repositioned slightly by withdrawing or repositioning parallel to the 1st ablation site, or by rotating the electrode, and a 2nd lesion made. Local corticosteroid injection is then performed at the ablation site at a total corticosteroid equivalent of 80mg triamcinolone, divided equally among the medial branches targeted; this dose can be reduced as needed according to the medical status of each patient. This process is applied for each medial branch nerve targeted.

Intervention Type PROCEDURE

Lumbar radiofrequency ablation with multi-tined electrodes (LRFA-M)

LRFA-M positions a multi-tined thermal radiofrequency electrode at each medial branch nerve to be ablated and administers local anesthetic to the nerve. However, the multi-tined thermal radiofrequency electrode is thought to achieve larger lesions and thus does not require parallel electrode placement; the LRFA-M electrode will be placed perpendicular to the medial branch nerve. All subsequent processes are the same as for LRFA-C. This includes local corticosteroid injection at each ablation site at a total corticosteroid equivalent of 80mg triamcinolone, divided equally among the medial branches targeted; this dose can be reduced as needed according to the medical status of each patient. This process is applied for each medial branch nerve targeted.

Intervention Type PROCEDURE

Simulated lumbar radiofrequency ablation

The simulated LRFA control procedure will be performed in an identical fashion to LRFA-M, except 1) after electrode positioning, a neurodestructive lesion will not be made; and 2) a pre-recorded audio recording of the procedure will be played (out of view of the patient, immediately adjacent to the RFA machine) in order to simulate the beeping and other sounds of the machine and to ensure the appropriate length of the simulated procedure. The electrode will remain in place for the 90-120 seconds that lesioning would normally take, but without heat application. The electrode will then be repositioned to simulate a second lesion, also of duration 90-120 seconds. Local corticosteroid injection is then performed at the ablation site at a total corticosteroid equivalent of 80mg triamcinolone, divided equally among the medial branches targeted; this dose can be reduced as needed according to the medical status of each patient. This process is applied for each medial branch nerve targeted.

Intervention Type PROCEDURE

Eligibility Criteria

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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 LRFA
* 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)
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)

NIH

Sponsor Role collaborator

University of Washington

OTHER

Sponsor Role lead

Responsible Party

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Janna Friedly

Multiple Principal Investigator

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Pradeep Suri, MD

Role: PRINCIPAL_INVESTIGATOR

University of Washington

Janna Friedly, MD

Role: PRINCIPAL_INVESTIGATOR

University of Washington

Locations

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Emory Musculoskeletal Institute

Atlanta, Georgia, United States

Site Status RECRUITING

Cleveland Clinic

Cleveland, Ohio, United States

Site Status RECRUITING

University of Utah Orthopaedic Center/PM&R

Salt Lake City, Utah, United States

Site Status NOT_YET_RECRUITING

Countries

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United States

Central Contacts

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Research Study Coordinator

Role: CONTACT

Phone: 206-210-4040

Email: [email protected]

Facility Contacts

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Emory Orthopedics Clinical Research

Role: primary

Nya Robinson

Role: primary

Research Study Coordinator

Role: primary

Related Links

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http://www.astralstudy.org

ASTRAL Study general information website

Other Identifiers

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U01AR084723

Identifier Type: NIH

Identifier Source: secondary_id

View Link

Pro00075903

Identifier Type: -

Identifier Source: org_study_id