The Clinical Efficacy of High-Voltage Long-Duration Pulsed Radiofrequency Treatment in Pudendal Neuralgia: A Retrospective Study

Abstract

Background: Patients with pudendal neuralgia (PN) experience long-lasting chronic pain, hyperalgesia, and comorbid emotional disorders, such as depression and anxiety. Treatment via conventional pulsed radiofrequency (PRF) current carries a significantly high rate of failure.

Objective: To determine the safety and clinical efficacy of high-voltage, long-duration PRF application to the pudendal nerve in patients with PN.

Study design: Observational retrospective design, self before-after controlled clinical trial.

Materials and methods: We analyzed the records of 70 patients of our hospital with diagnosed PN. Treatment consisted of PRF application to the pudendal nerve, using computed tomography guidance to target the pudendal nerve at the level of the ischial spine or ischial tuberosity of the affected side. PRF was applied with the following parameters: temperature 42 °C, frequency 2 Hz, pulse width 20 ms, field intensity ramped gradually from 40 to 90 V, duration 900 sec. The therapeutic effect was evaluated by collecting patient scores for the visual analog scale (VAS), SF-36 health survey questionnaire (SF-36), and patient health questionnaire (PHQ-9) before treatment and at 1-, 4-, and 12-week follow-ups after PRF treatment. Data were analyzed by paired t-test with p < 0.05 considered to be statistically significant.

Results: VAS, SF-36, and PHQ-9 scores at 1, 4, and 12 weeks after high-voltage long-duration PRF treatment were significantly improved relative to their respective pretreatment baseline scores (p < 0.05 for all). The effective rate at 12 weeks after high-voltage long-duration PRF was up to 88.6%.

Limitations: A small sample size and lack of a control group.

Conclusions: High-voltage long-duration PRF provided significant short-term (at least 12 weeks) pain relief to most patients with PN; it also improved subjective measures of depression and quality of life over the same duration of time.

Keywords: CT-guided; PHQ-9; SF-36; VAS; neuropathic pain; pudendal nerve block; pudendal nerve entrapment; pulsed radiofrequency.