Radiofrequency thermocoagulation with glycerin rhizotomy compared with glycerin rhizotomy alone for pain improvement in repeat rhizotomy

Because of the frequent recurrence of pain for patients with trigeminal neuralgia (TN), many undergo repeat percutaneous rhizotomy. The aim of this study was to assess whether the use of radiofrequency thermocoagulation with glycerin rhizotomy (RFTC-GR) or GR alone in repeat rhizotomy procedures influences postoperative pain and numbness outcomes. The electronic medical records of 465 patients with TN who underwent repeat rhizotomy at the authors' institution between 2011 and 2022 were reviewed. Patients were dichotomized by treatment type: RFTC-GR or GR. Baseline demographics, comorbidities, and clinical characteristics were collected. The primary outcomes measured were pain and numbness, preoperatively and postoperatively, using the modified Barrow Neurological Institute (BNI) pain intensity scale and the BNI facial numbness scale. To compare pain and numbness outcomes between the RFTC-GR and GR groups, Kaplan-Meier, multivariate ordinal regression, and Cox proportional hazards analyses were performed. Preoperatively, patients who received RFTC-GR had higher BNI pain scores and lower BNI numbness scores than those who received GR alone. Postoperatively, patients in the RFTC-GR group had higher BNI numbness scores than patients in the GR group, but the RFTC-GR group had significantly less rhizotomy failure (defined as a BNI pain score > 3 within 90 days after surgery). Multivariate ordinal regression analysis determined that RFTC-GR was associated with higher BNI numbness scores at the time of pain recurrence or the final follow-up (p = 0.04). A Cox proportional hazards model demonstrated that glycerin-only rhizotomy was associated with greater risk of failure compared with RFTC-GR (p < 0.01). In this study, RFTC-GR caused greater postoperative numbness than GR alone, while reducing the risk of rhizotomy failure compared with GR. Thus, RFTC-GR could be a more appropriate repeat procedure for patients with minimal numbness preoperatively.