NCT07222462

A Superiority Trial of Radiofrequency Ablation for Low Back Pain

ASTRAL: A Superiority Trial of Radiofrequency Ablation for Low Back Pain

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 300 (estimated)
• Sponsor: University of Washington · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

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

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

• Chronic Low Back Pain (CLBP)

Interventions

Type	Name	Description
PROCEDURE	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.
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.
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.

Timeline

• Start date: 2026-02-04
• Primary completion: 2029-03-01
• Completion: 2029-08-01
• First posted: 2025-10-29
• Last updated: 2026-02-09

Locations

3 sites across 1 country: United States