Pulsed Radiofrequency Therapy at Different Voltages on Dorsal Root Ganglia Using Multifunctional Catheter to Treat Low Back Pain: A Comparative Retrospective Study.

Background: Applying pulsed radiofrequency (PRF) to the dorsal root ganglion (DRG) is an electrical neuromodulation technique, a valid complementary therapeutic treatment for failed back surgery syndrome (FBBS). Peridurolysis, when applied to vertebral canal adhesions, can be performed with dedicated catheters, providing patients with the benefits of mechanical, electrical, and pharmacological techniques.

Objectives: The aim of this study was to evaluate PRF's effects on the DRG as part of FBSS treatment at different follow-up times, comparing 2 groups of patients exposed to distinct levels of voltage (100 V vs. 45 V) from a PRF generator.

Study Design: A retrospective observational study was performed.

Setting: The study was conducted on a sample of patients from an Italian hospital.

Methods: PRF's effects on the DRG as part of FBSS treatment were evaluated through the Numeric Rating Scale (NRS) and the monitoring of 155 patients' opioid consumption at 3, 6, and 9 months. A Cosman® G4 model PRF generator was used. During follow-up periods, the Friedman test was applied to detect differences in outcomes between the 2 groups of patients, who were treated with different levels of voltage.

Results: The most frequent diagnosis (61.29%) was FBBS in patients at a mean age of 64 (± 11.8) years old. All patients were treated with PRF on the dorsal ganglion, with the addition of a drug mixture. Most were treated with 100 V (62%). A statistically significant decrease (P < 0.001) in the NRS score emerged both as a whole and in the 2 distinct groups. Moreover, the group of 100 V patients showed a significant (P = 0.0360) reduction in the use of opioids.

Limitations: This observational retrospective study was based on a convenience sampling that involved a limited number of patients.

Conclusions: E-field technology is the only way to generate a constant 38°/42° PRF and 100 V level throughout surgical interventions (respecting the exposure times "set" by the operator). The patient will not feel any pain or electric current because the generated milliamperes will be greatly reduced.