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Videosurgery and Other Miniinvasive Techniques
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vol. 15
Original paper

Efficacy of coblation versus radiofrequency thermocoagulation for the clinical treatment of trigeminal neuralgia

Yanda Lin
Jiaxiang Ni
Xinlu Zuo
Liqiang Yang
Liangliang He
Yuanzhang Tang
Chengli Sun

Department of Pain Management, Xuanwu Hospital, Capital Medical University, Beijing, China
Department of Nursing, Chengde Nursing Vocational College, Chengde, China
Videosurgery Miniinv 2020; 15 (4): 620–624
Online publish date: 2020/01/19
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Idiopathic trigeminal neuralgia (ITN) is severe chronic neuropathic facial pain, characterized by recurrent episodes of intense, lancinating pain localized to dermatomes of the face innervated by the trigeminal nerve [1]. Oral medication, rapid and convenient, is the first-line therapy for ITN [2]. However, for medication-resistant or medication-intolerant ITN, surgical treatment needs to be considered [3].

Because of minimal trauma and long-term pain relief, percutaneous trigeminal radiofrequency thermocoagulation (PT-RFT) has become a primary minimally invasive surgical treatment modality [4]. However, the technique is associated with a high incidence of post-operative facial numbness because of nerve injury caused by the high temperatures needed for thermocoagulation [5]. In comparison, coblation has been reported to produce only slight numbness when used to ablate the thoracic paravertebral nerve [6]. The relatively low working temperature (40–70°C) and the short thermal penetration distance (~1.0 mm) of coblation might help preserve neural function.


In our previous study, we provided preliminarily data showing that coblation can reduce the degree of postoperative facial numbness in patients with ITN in the short term [7]. In the present study, we further evaluate the long-term efficacy and safety of ablating the trigeminal ganglion with coblation technology under fluoroscopic guidance.

Material and methods

The randomized, prospective, clinical study was approved by the institutional Ethics Examining Committee of Human Research. A total of 56 patients with TN provided written informed consent, and were randomly scheduled to receive coblation (coblation group) or PT-RFT (RFT group) of the trigeminal ganglion between January, 2017 and June, 2018. ITN was diagnosed according to the criteria of the International Classification of Headache Disorders-II (2004).

After entering the sterile operating room, all patients received standard monitoring, that is, heart and respiratory rate, and fingertip digital oximetry. A 0.5 g dose of atropine was administered intravenously 5 min prior to surgery to block the trigeminal–baroreceptor reflex, and a 50 µg dose of fentanyl was injected intravenously to provide analgesia. No other sedatives were given, to maintain consciousness and responsiveness to nerve root stimulation during surgical procedures.

All surgical procedures were performed under fluoroscopic guidance, with the patient in the supine position. A soft pad of 10 cm thickness was placed under the neck to retroflex the head approximately 45°. Fluoroscopic guidance was performed with the OEC 9900 Elite C-Arms (the American, GE). The preset coronal and sagittal angles of the X-ray tube to reveal the foramen ovale (FO) were 10° and 10°, pre-operatively (Photo 1 B).

Photo 1

A – Lateral view of C-arm showed that the depth of the needle tip was not beyond the clivus. B – For the coaxial view, the preset coronal and sagittal angles of the X-ray tube to reveal the foramen ovale (FO) were 10° and 10°


After clearly visualizing the FO, an 18-gauge, 8-cm, guide needle was inserted through the sterilized skin after local anesthesia with 0.5% lidocaine with the “Haertel” approach. During the puncture procedure, advancement was stopped when the needle entered the FO, and the coblation wand (UNITEC, China America United Technology (Beijing) Co. Ltd, Beijing, China) was inserted into the guide needle and extended approximately 5 mm beyond its tip. The correct coblation wand position was checked radiologically in coaxial and lateral views, and the depth of the tip of the coblation wand was not beyond the clivus. Test coagulation for 0.5–1 s, with the radiofrequency controller set at intensity setting #1, was performed to re-adjust the coblation wand position with the patient awake and responsive. Intravenous anesthesia with propofol (1–2 mg/kg) and fentanyl (50 µg) was administered after verifying the final position of the wand tip, and the ablation of ganglion was performed at intensity setting #2 for a duration of 30 s. Depending on the nerve branch and the physician’s judgment, ablation was performed 2 or 3 times. After PT-RFT or coblation, all patients were asked to remain in bed for 48 h to prevent intracranial hypotension headache.

Preoperative data, including age, gender, location of pain and preoperative visual analog scale (VAS) score, were recorded. Follow-up evaluation was performed on the first day and at the end of the first month, third month, sixth month and first year after surgery. To assess the degree of numbness, the numbness rating scale described in our previous report was used [8] (Table I).

Table I

Numbness rating classification

0No numbness
INo obvious numbness
IIMild numbness, occasionally affects daily life
IIIModerate numbness, frequently affects daily life
IVPainful numbness, severely affect daily life

Statistical analysis

In this study, a sample size of 25 per group was used to obtain a power of 90% to show a difference of 6 points on the VAS between the two groups at a significance level of 5% (two-tailed). Taking into account a potential dropout rate of 10% (3 patients), we increased the sample size to 28 per group. All data were analyzed with SPSS version 19.0, using mean and standard deviation, with t-test and rank-sum test for post hoc comparisons. Statistical significance was accepted at p < 0.05.


A total of 50 patients with TN were ultimately included in this study (3 cases were dropped from each group for logistical reasons). The basic preoperative data for the two groups are shown in Table II. There were no significant differences in gender, age, pain location or preoperative VAS score between the two groups.

Table II

Characteristics of patients

Patients (n)2525
Gender (women/men), n (%)19 (76)/6 (24)14 (56)/11 (44)
Age [years]62.56 ±11.2362.88 ±13.84
Presurgery VAS7.48 ±1.337.68 ±1.18
Branches affected:
Pain side:

[i] RFT – radiofrequency thermocoagulation, CB – coblation, V2 – maxillary division, V3 – mandibular division. Data are presented as numbers (%) of patients or mean ± SD.

Post-surgery VAS scores were significantly lower in both groups compared with pre-surgery scores (p < 0.05), indicating that both methods effectively alleviated pain. At each time point, from 1 day to 1 year, the VAS scores and other parameters were not significantly different between the two groups (p > 0.05) (Figure 1).

Figure 1

Postprocedure VAS scores between two groups

CB – coblation, RFT – radiofrequency thermocoagulation, P – presurgery.


Among the patients, 19 (76%) developed different degrees of facial numbness (grades II–IV) after PT-RFT, while 13 (52%) experienced facial numbness after coblation. One patient in the PT-RFT group experienced painful numbness (grade IV), which subsided to grade III 1 year after surgery, while no patient exhibited painful numbness in the coblation group. The rank-sum test for facial numbness degree showed that the patients in the PT-RFT group experienced more severe numbness than the patients in the coblation group, and these differences were statistically significant (p < 0.05) (Table III).

Table III

Comparison of degree of postoperative facial numbness in the 2 groups

Numbness degreeGroup RFGroup CB
1 D1 M6 M1 Y1 D1 M6 M1 Y
Grade 000000001
Grade I666612131919
Grade II9121113121064
Grade III96761201
Grade IV11100000

Additional post-procedural complications included masseter weakness in 4 (9.1%) patients in the PT-RFT group and in 3 patients in the coblation group. In addition, 1 patient in the PT-RFT group developed hypogeusia, and 1 patient had dysacusis after surgery. All patients improved during follow-up. No mortality was observed in these 50 patients.


PT-RFT is widely used in the treatment of TN when drugs are ineffective or when adverse effects are intolerable [9]. As a minimally invasive technique, PT-RFT has the same efficacy as microvascular decompression (MVD), but with lower surgical risk [10]. However, postoperative facial numbness, a major complication of PT-RFT, limits this procedure [11]. The high temperatures, of over 65°C, are thought to selectively destroy the Aδand C pain fibers, as these are more susceptible to heat damage than Aα and Aβ tactile fibers [12]. Thus, the facial numbness after PT-RFT might be caused by the heat produced by the PT-RFT needle. In contrast to PT-RFT, coblation technology uses radiofrequency energy to excite the electrolytes in a conductive medium such as saline solution [13]. The coblation needle produces energized plasma that can break molecular bonds, causing tissue dissolution at a relatively low temperature (40–70°C) [14, 15].

Recently, coblation has been used in pain management for different conditions [6, 1416]. In a case report of phantom limb pain, Li et al. found that coblation of the cervical nerve root successfully reduced the degree of pain [16]. Yang et al. reported on the efficacy of coblation of the thoracic paravertebral nerve for the treatment of thoracic neuropathic pain, and found that most patients experienced significant pain relief after surgery. Furthermore, all patients reported slight numbness after surgery, but the degree of numbness had no major impact on their daily lives [6]. Li et al. made a preliminary evaluation of the short-term efficacies of coblation and PT-RFT in treating ITN, and found that coblation reduced the risk of postoperative numbness, while reducing pain to the same degree as PT-RFT [7].

In this report, we compared the efficacy and rates of postoperative facial numbness of PT-RFT and coblation. Compared with patients in the PT-RFT group, the patients in the coblation group experienced similar pain relief, but with milder numbness; this was probably because the lower operating temperatures of coblation are less likely to damage surrounding nerves. Furthermore, the coblation needle is surrounded by normal saline as a conductive medium, which may also reduce damage to the surrounding tissue.


Coblation has a similar efficacy in reducing pain as PT-RFT, but with a lower rate of postoperative facial numbness. Therefore, coblation might be a better choice for treating TN.

Conflict of interest

The authors declare no conflict of interest.



Zheng S, Wu B, Zhao Y, et al. , authors. Masticatory muscles dysfunction after CT-guided percutaneous trigeminal radiofrequency thermocoagulation for trigeminal neuralgia: a detailed analysis. Pain Pract. 2015. 15:p. 712–9


Maarbjerg S, Di Stefano G, Bendtsen L, et al. , authors. Trigeminal neuralgia – diagnosis and treatment. Cephalalgia. 2017. 37:p. 648–57


Maesawa S, Salame C, Flickinger JC, et al. , authors. Clinical outcomes after stereotactic radiosurgery for idiopathic trigeminal neuralgia. J Neurosurg. 2001. 94:p. 14–20


Jin HS, Shin JY, Kim YC, et al. , authors. Predictive factors associated with success and failure for radiofrequency thermocoagulation in patients with trigeminal neuralgia. Pain Physician. 2015. 18:p. 537–45


Tang YZ, Wu BS, Yang LQ, et al. , authors. The long-term effective rate of different branches of idiopathic trigeminal neuralgia after single radiofrequency thermocoagulation: a cohort study. Medicine. 2015. 94:p. e1994


Yang LQ, Gong WY, Wang XP, et al. , authors. Computed tomography-guided percutaneously controlled ablation of the thoracic paravertebral nerve due to thoracic neuropathic pain. Pain Pract. 2017. 17:p. 792–9


Li Y, Guo Y, Yang L, et al. , authors. Comparison of the short-term outcomes after low-temperature plasma radiofrequency ablation (coblation) in the Gasserian ganglion for the treatment of idiopathic trigeminal neuralgia. J Pain Res. 2019. 12:p. 1235–42


Tang YZ, Jin D, Bian JJ, et al. , authors. Long-term outcome of computed tomography-guided percutaneous radiofrequency thermocoagulation for classic trigeminal neuralgia patients older than 70 years. J Craniofac Surg. 2014. 25:p. 1292–5


Kosugi S, Shiotani M, Otsuka Y, et al. , authors. Long-term outcomes of percutaneous radiofrequency thermocoagulation of gasserian ganglion for 2nd- and multiple-division trigeminal neuralgia. Pain Pract. 2015. 15:p. 223–8


Tang YZ, Jin D, Li XY, et al. , authors. Repeated CT-guided percutaneous radiofrequency thermocoagulation for recurrent trigeminal neuralgia. Eur Neurol. 2014. 72:p. 54–9


Lopez BC, Hamlyn PJ, Zakrzewska JM , authors. Systematic review of ablative neurosurgical techniques for the treatment of trigeminal neuralgia. Neurosurgery. 2004. 54:p. 973–83


Kanpolat Y, Savas A, Bekar A, et al. , authors. Percutaneous controlled radiofrequency trigeminal rhizotomy for the treatment of idiopathic trigeminal neuralgia: 25-year experience with 1,600 patients. Neurosurgery. 2001. 48:p. 524–34


Li S, Chen R, Chen Y, et al. , authors. Therapeutic effects and safety of percutaneous disc decompression with coblation nucleoplasty in cervical vertigo: a retrospective outcome study with 74 consecutive patients and minimum 1-year follow-up. Pain Physician. 2019. 22:p. E205–14


Azzazi A, AlMekawi S, Zein M , authors. Lumbar disc nucleoplasty using coblation technology: clinical outcome. J Neurointerv Surg. 2011. 3:p. 288–92


Zeng Y, Wang X, Guo Y, et al. , authors. Coblation of femoral and sciatic nerve for stump pain and phantom limb pain: a case report. Pain Pract. 2016. 16:p. E35–41


Li H, Li Y, Guo Z, et al. , authors. Low-temperature plasma radiofrequency ablation in phantom limb pain: a case report. Brain Circ. 2018. 4:p. 62–4

Copyright: © 2020 Fundacja Videochirurgii This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) License (http://creativecommons.org/licenses/by-nc-sa/4.0/), allowing third parties to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material, provided the original work is properly cited and states its license.
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