Background: Percutaneous radiofrequency ablation (RFA) of the trigeminal Gasserian ganglion via the foramen ovale is still one of the classic treatments for primary trigeminal neuralgia. However, the Gasserian ganglion is deep in the middle cranial fossa. Although it is a structure outside the brain tissue, the puncture needle must enter the encephalic to reach the Gasserian ganglion and so it is difficult to completely avoid the risk of intracranial hemorrhage and infection caused by puncture damage to intracranial blood vessels. It is not clear whether if it is possible for RFA at the extracranial non-gasserian-ganglion site via the exit of the cranial channel (foramen ovale) for patients with V3 trigeminal neuralgia (TN).
Study design: Prospective, clinical research study.
Setting: Department of Anesthesiology and Pain Medical Center, Jiaxing, China.
Methods: One hundred and seven patients with isolated mandibular branch trigeminal neuralgia were included. Radiofrequency thermocoagulation was performed by CT-guided percutaneous puncture through the foramen ovale. The puncture target was the midpoint of the horizontal transverse diameter of the oval foramen. If the tingling sensation in the mandibular nerve innervation area could be detected, the radiofrequency thermocoagulation (90°C, 120 sec) under intravenous anesthesia would be performed. We investigated the inclination angle, puncture angle and depth, puncture operation time, intraoperative complications and short-term and long-term results after operation.
Results: After radiofrequency thermocoagulation, the pain in the mandibular branch dominant area was completely diminished in 104 patients. Two patients were cured after the second radiofrequency treatment. No intracranial hemorrhage not infection complications occurred, except for facial hematoma during operation in 21 cases. After 12-24 months of follow-up, 9 patients had recurrence and were still effective after receiving additional extracranial radiofrequency treatment.
Limitations: A control group should be established and more clinical data should be collected in future work.
Conclusion: Extracranial non-Gasserian-ganglion RF can achieve satisfactory results and improve the safety of radiofrequency treatment for trigeminal neuralgia.
Keywords: foramen ovale; trigeminal ganglion; Trigeminal neuralgia.