CT Guided Pudendal Nerve Block

Purpose: Retrospective review of CT-guided pudendal nerve blockade for chronic pelvic pain caused by pudendal neuralgia. Materials & Methods: The study included 23 patients (average age, 40.6 yr; range, 25 - 71 yr) diagnosed with pudendal neuralgia. Diagnostic criteria were: pain in the anatomic distribution of the pudendal nerve, pain worsening with sitting, pain relieved by lying down, and no sensory loss on examination. Alternative etiologies were considered and, if present, patients were excluded from the study. Patients underwent 1 - 4 CT-guided pudendal nerve blocks, using 22-gauge spinal needles placed with intermittent CT guidance. The needles were directed to the expected path of the pudendal nerve, either immediately caudal to the ischial spine or in Adcock’s canal. Nerve blocks were performed with 1 cc depot methylprednisolone (40 mg/cc), Bupivacaine 0.25% (3 cc) and Lidocaine 2% (2 cc). Procedure times were recorded. Patients were examined for perineal and vulva anesthesia 1 h after the blocks were performed. Patients’ records were reviewed for procedural success and complications. Results: Procedure time was 17.1 min (range, 11 - 26). Twenty-one blocks were performed at the ischial spine, and 2 were performed at the pudendal canal. Twenty-two (95.6%) of 23 patients reported perineal analgesia after the injection was performed, for a procedural success rate of 96%. One patient developed bilateral leg weakness which resolved in 6. Conclusion: Pudendal nerve block can be performed with CT guidance in a safe and effective manner. Further evaluation of the long-term effectiveness of the procedure with a prospective study is warranted.