<p>Bipolar radiofrequency ablation of mandibular branch for refractory V3 trigeminal neuralgia</p>

Abstract

Background: Percutaneous trans-foramen ovale (FO) radiofrequency ablation (RFA) of Gasserian ganglion (GG) is commonly used to treat V3 trigeminal neuralgia (TN). However, this intracranial approach is less selective and safe. Objectives: To report a novel percutaneous within-FO RFA of the V3 under CT-guidance and outcomes with both bipolar and monopolar techniques. Patients and methods: Twenty-six patients with isolated V3 primary TN and FO >6 mm in diameter underwent either monopolar (n=12) or bipolar RFAs (n=14) based on their preference. Successful analgesia over V3, residual pain, recurrent pain, and complications were compared between the two groups. The ex vivo egg albumen model was used to demonstrate the size difference in the thermocoagulation lesion created by monopolar vs bipolar electrodes. Results: In the bipolar group, there were more cases of masticatory atonia as compared to the monopolar ( P =0.104), but no residual pain was observed. In the monopolar group, there were two cases of residual pain found, which led to immediate repeat RFAs. Therefore, during the immediate post-operative period, both groups obtained 100% complete V3 analgesia with a similar risk of facial hematoma ( P =0.641). During up to 27-months of post-operative follow-up, in the bipolar group, complete pain relief persisted in all patients; in the monopolar group, 1 case of recurrent pain was found at 14 months. Ex vivo study demonstrated that, at 90 °C/90 seconds of RFA, the width of lesions is significantly larger by the 6-mm spacing parallel-tip bipolar electrodes compared to the monopolar electrode (9.5±0.567 vs 5.5±0.07 mm). Conclusion: In treating patients with isolated V3 TN and FO >6mm in diameter, this percutaneously within-FO RFA of the V3 under CT guidance is both clinically practical and effective, while bipolar RFA is associated with a lower incidence of residual and recurrent pain likely due to larger lesion sizes.

Invasive and Non-Invasive Electrical Neuromodulation in Trigeminal Nerve Neuralgia: A Systematic Review and Meta-Analysis

“…Radiofrequency produces a rise in tissue temperature through a high-frequency current that circulates between two electrodes (one placed on the external surface and the other one on the tissue to be treated). This current generates an electric field that causes ionic vibrations, which produce thermal heat that consequently leads to the thermocoagulation of the tissue [ 50 , 54 , 55 ]. The procedure is easy and quick, lasting for about 10 minutes.…”

Effects of Supraorbital Foramen Variations on the Treatment Efficacy of Radiofrequency Therapy for V1 Trigeminal Neuralgia: A Retrospective Study

“…ese findings suggested that with high temperature of Table 3: Numbness degree on day 1 and at 2 y after operation between the two groups (n(%)). [15][16][17]. In this study, high temperature (95°C) was adopted for radiofrequency therapy to reduce thermal attenuation caused by the distance from the radiofrequency target and target nerve, which in turn leads to incomplete nerve destruction and high relapse rate.…”

Evaluation of the Efficacy of Unipolar and Bipolar Spinal Dorsal Root Ganglion Radiofrequency Thermocoagulation in the Treatment of Postherpetic Neuralgia: a Retrospective Study

“…Previous studies have shown that the effect of simple pulsed radiofrequency is not successful, whereas the therapeutic effect of pulsed radiofrequency combined with radiofrequency thermocoagulation is suitable for its clinical use 26,27 . In the comparative study of unipolar and bipolar groups, it was found that the bipolar group exhibited more advantages in pain relief and functional recovery 16,21 . In the clinical treatment of postherpetic neuralgia, the discussion and research of unipolar and bipolar radiofrequency have not been reported.…”

“…In order to assess the optimal thermal coagulation effect of bipolar more clearly, we explored the radio frequency duration and bipolar distance in the ovalbumin in vitro test 32 . The in vitro ovalbumin model is often used to simulate the internal environment of the human body 21,33 . The results of the ovalbumin in vitro test indicated a difference in the effects of radiofrequency thermocoagulation between the bipolar and unipolar groups.…”

“…Nowadays, PRF combined with local anesthetics and hormone injection is often used in the clinic to improve the clinical treatment effect. Overall, the pain relief rate of Radiofrequency thermocoagulation was signi cantly higher than that of PRF 20,21 . Therefore, it is urgent to seek a newer and more effective radiofrequency therapy for patients with postherpetic neuralgia.…”