Pulsed radiofrequency treatment in interventional pain management: mechanisms and potential indications—a review

Item does not contain fulltextBACKGROUND: The objective of this review is to evaluate the efficacy of Pulsed Radiofrequency (PRF) treatment in chronic pain management in randomized clinical trials (RCTs) and well-designed observational studies. The physics, mechanisms of action, and biological effects are discussed to provide the scientific basis for this promising modality. METHODS: We systematically searched for clinical studies on PRF. We searched the MEDLINE (PubMed) and EMBASE database, using the free text terms: pulsed radiofrequency, radio frequency, radiation, isothermal radiofrequency, and combination of these. We classified the information in two tables, one focusing only on RCTs, and another, containing prospective studies. Date of last electronic search was 30 May 2010. The methodological quality of the presented reports was scored using the original criteria proposed by Jadad et al. FINDINGS: We found six RCTs that evaluated the efficacy of PRF, one against corticosteroid injection, one against sham intervention, and the rest against conventional RF thermocoagulation. Two trials were conducted in patients with lower back pain due to lumbar zygapophyseal joint pain, one in cervical radicular pain, one in lumbosacral radicular pain, one in trigeminal neuralgia, and another in chronic shoulder pain. CONCLUSION: From the available evidence, the use of PRF to the dorsal root ganglion in cervical radicular pain is compelling. With regards to its lumbosacral counterpart, the use of PRF cannot be similarly advocated in view of the methodological quality of the included study. PRF application to the supracapular nerve was found to be as efficacious as intra-articular corticosteroid in patients with chronic shoulder pain. The use of PRF in lumbar facet arthropathy and trigeminal neuralgia was found to be less effective than conventional RF thermocoagulation techniques

A Randomized Controlled Trial to Evaluate the Effect of Pulsed Radiofrequency as a Treatment for Anterior Cutaneous Nerve Entrapment Syndrome in Comparison to Anterior Neurectomy

BACKGROUND: Chronic abdominal pain can be due to entrapped intercostal nerves (anterior cutaneous nerve entrapment syndrome [ACNES]). If abdominal wall infiltration using an anesthetic agent is unsuccessful, a neurectomy may be considered. Pulsed radiofrequency (PRF) applies an electric field around the tip of the cannula near the affected nerve to induce pain relief. Only limited retrospective evidence suggests that PRF is effective in ACNES. METHODS: A multicenter, randomized, nonblinded, controlled proof-of-concept trial was performed in 66 patients. All patients were scheduled for a neurectomy procedure. Thirty-three patients were randomized to first receive a 6-minute cycle of PRF treatment, while the other 33 were allocated to an immediate neurectomy procedure. Pain was recorded using a numeric rating scale (NRS, 0 [no pain] to 10 [worst pain possible]). Successful treatment was defined as >50% pain reduction. Patients in the PRF group were allowed to cross over to a neurectomy after 8 weeks. RESULTS: The neurectomy group showed greater pain reduction at 8-week follow-up (mean change from baseline -2.8 (95% confidence interval [CI] -3.9 to -1.7) vs. -1.5 (95% CI -2.3 to -0.6); P = 0.045) than the PRF group. Treatment success was reached in 12 of 32 (38%, 95% CI 23 to 55) of the PRF group and 17 of 28 (61%, 95% CI 42 to 72) of the neurectomy group (P = 0.073). Thirteen patients were withdrawn from their scheduled surgery. Adverse events were comparable between treatments. CONCLUSIONS: PRF appears to be an effective and minimally invasive treatment option and may therefore be considered in patients who failed conservative treatment options before proceeding to a neurectomy procedure. Anterior neurectomy may possibly lead to a greater pain relief compared with PRF in patients with ACNES, but potential complications associated with surgery should be discussed