Dual Site Pudendal Nerve Infiltration: More than Just a Diagnostic Test?

Background: Pudendal neuralgia (PN) is a very painful and often disabling condition in which pudendal nerve blocks play an important role in both the diagnosis and management of PN. Some previous reports have advocated the use of pudendal nerve infiltration (PNI) as a diagnostic test only. Objective: We aim to assess the outcomes of patients with typical refractory PN who underwent dual site computed tomography (CT)-guided pudendal nerve infiltration. Study Design: A bicentric, retrospective cohort analysis. Setting: An academic practice. Methods: Between 2002 and 2016, 385 PNIs were performed in 195 patients in the 2 units. Only patients suffering from typical clinical PN were included, and only the first infiltration in each patient was considered for analysis. Therefore, 95 patients who underwent 155 procedures were assessed. Pain was assessed using a visual analog scale (0-10) and self-reported estimated improvement (SRI), expressed as a percentage. Efficacy of the procedure was assessed at 1, 3, and 6 months after procedure follow-up, and clinical success was defined as a 50% decrease of the VAS score. All procedures were performed under CT guidance and on an outpatient basis. Dual site infiltration was performed in each case at both the ischial spine and intra-Alcock's canal sites using a mixture of fast- and slow-acting anesthetic (1 mL lidocaine hydrochloride 1% and 2 mL ropivacaine chlorhydrate) along with a half dose of 1.5 mL of cortivazol (3.75 mg). Results: Clinical success at one month post-procedure was present in 63.2% of patients (60/95) with a mean VAS score of 2.07 (P < 0.05) and a mean SRI of 71%. At 3 months follow-up, clinical success was still present in 50.5% of patients (48/95) with a mean VAS score of 2.90/10 (P < 0.05) and a mean SRI of 62.3%. At 6 months follow-up, the efficacy rate decreased to 25.2% with a mean VAS score of 3.2/10 and SRI of 60%. Limitations: The retrospective aspect of the study is a limitation, as well as the lack of a control group. Conclusion: Dual site PNI under CT guidance may offer significant mid-term pain relief to a majority of patients suffering from typical refractory PN.