Therapeutic Efficacy of Ultrasound-Guided High-Voltage Long-Duration Pulsed Radiofrequency for Pudendal Neuralgia

Abstract

Pudendal neuralgia (PN) is a complex disease with various clinical characteristics, and there is no treatment showing definite effectiveness. This study is aimed at evaluating the clinical efficacy of ultrasound-guided high-voltage long-duration pulsed radiofrequency (PRF) for PN. Two cadavers (one male, one female) were dissected to provide evidence for localization of the pudendal nerve. Patients diagnosed as PN who failed or were intolerant in regular medication were screened for diagnostic local anesthesia block of the pudendal nerve before recruitment. Twenty PN patients were enrolled in this study. In the PRF procedure, the needle tip was inserted medially into the internal pudendal artery under ultrasound guidance. The position of the PRF needle tip was then adjusted by the response of the pudendal nerve to the electrical stimulation within the pudendal area (42°C, a series of 2 Hz, and 20 ms width pulses that lasted for 900 s). Alleviation of pain was assessed by the visual analogue scale (VAS) and sitting time pretreatment and on 7 d, 14 d, 1 m, 2 m, 3 m, and 6 m posttreatment in outpatient follow-up or by telephone interview. Two patients were lost due to intervention-irrelevant reasons. Patients showed significantly decreased VAS scores on 7 d after RFP, compared with pretreatment status ( 7.0 ± 0.9 vs. 3.2 ± 1.7 , P < 0.001 ). The efficacy remained steady till the end of 6 months, with a final remission rate of 88.9%. Sitting time also significantly lengthened following PRF (7 d, 14 d, 1 m, 2 m, 3 m, and 6 m vs. pretreatment, all P < 0.05 ). Only short-term ipsilateral involuntary convulsion of the lower extremity was reported in one patient, who recovered within 12 h. Six patients were treated with nonsteroidal drugs for a short time. All patients stopped taking medication finally. In conclusion, the ultrasound-guided high-voltage long-duration PRF approach not only reduced the pelvic pain caused by PN but also improved the quality of life by extending sitting time without nerve injury.

Progress in Clinical Application of Pulsed Radiofrequency for Chronic Pain

“…In one study, the success rate of repeated PRF after long-term follow-up was 89% [13], similar to the success rate of 92.1% described by Fang et alin a randomized controlled trial with only 3 months of follow-up [14]. Moreover, high-voltage long-term PRF treatment can relieve the pain of patients with pudendal neuralgia and improve their quality of life by prolonging sitting time without significant serious adverse events [15]. In addition, a retrospective study included 88 adult PN patients whose VAS standardized pain scores were significantly reduced by more than 70% within 3 days after treatment (short term) in both the nerve block and PRF groups.…”

Efficacy of ganglion impar block combined with pudendal nerve pulsed radiofrequency for pudendal neuralgia management—a randomized clinical trial

“…However, the ultrasound-guided PRF of the pudendal nerve combined with GIB is used in PN, but randomized controlled trials are lacking. In the above studies, the PRF parameters were set as follows: temperature ranging from 42 ℃ to 45 ℃ with a duration from 120 to 900 s. Although the high-voltage long-duration PRF mode shows better improvement in PN [ 12 ], based on our clinical experience and to avoid discomfort, PRF will be administered at 42 ℃ for 480 s in our study. Our primary outcome will be the efficacy of PRF combined with GIB for the long-term improvement of PN.…”

“…Fang et al [ 10 ] showed that pudendal nerve PRF combined with PNB provides longer-lasting pain relief and alleviates depression in patients compared with PNB. Ji et al [ 12 ] found that PN was alleviated after 6 months in 88.9% of the patients who received ultrasound-guided high-voltage long-duration PRF. At long-term follow-up (ranging from 2.3 years to 8.8 years), Krijnen et al found that 89% of patients who received repeated PRF with a median interval duration of 3 months between two sessions described their condition as “(very) much better” [ 13 ].…”

“…At long-term follow-up (ranging from 2.3 years to 8.8 years), Krijnen et al found that 89% of patients who received repeated PRF with a median interval duration of 3 months between two sessions described their condition as “(very) much better” [ 13 ]. No difference was observed between PNB and PRF immediately after the procedure, although PRF provided significant improvement in pain for 2 weeks to 3 months [ 12 , 14 ].…”

Dorsal Root Ganglion Stimulation Therapy for Refractory Idiopathic Pudendal Neuralgia

“…Another study compared radiofrequency ablation with standard pudendal nerve blocks in 88 patients with pudendal neuralgia. It found rough equivalency in pain relief out to 30 days but improved symptoms with pulsed radiofrequency therapy extending from one to three months [16,17]. Analogous to radiofrequency ablation, cryotherapy of the pudendal nerve is also a promising modality, based on a recent case series, which reported an average reduction in pain of 60% for up to six months after the procedure [18].…”