CT-guided blocks and neuroablation of the ganglion impar (walther) in perineal pain anatomy, technique, safety, and efficacy

Objective: An alternate approach to the ganglion impar was chosen to minimize the risk of adverse events. Efficacy of the procedure was evaluated. Methods: Charts and computed tomography (CT)-scans of patients who underwent block and neuroablation of the ganglion impar (Walther) between 2003 and 2007 were systematically reviewed with respect to adverse events and efficacy by rating pain intensity. A total of 76 blocks were performed, 48 of them being diagnostic blocks and 28 neuroablations. Chemical destruction was performed with ethanol, if pain recurred despite injection of local anesthetic. Results: Interventional pain therapy was performed in 43 patients (age: 64.6±12.4 y, median 49.5 y, range: 36 to 86 y, male/female: 27/16) presenting with perineal pain of unknown origin (n=15), carcinoma of the prostate (n=8), colorectal carcinoma (n=7), postsurgery of thrombosis of perineal veins (n=3), postherpetic neuralgia (n=4), malformation of the spinal cord (n=2), vaginal protrusion (n=2), failed back surgery syndrome (n=1), and ablation of testis (n=1). CT-guided puncture was not associated with any adverse events and resulted in a reduction of numeric rating scale values from 8.2±1.6 to 2.2±1.6 (P<0.0001, 95%confidence interval 0.5) immediately at discharge and to 2.2±1.4 (P<0.0001, 95% confidence interval 0.4) at 4 months on follow up. Discussion: CT-guided block and neuroablation of the ganglion impar (Walther) results in a significant reduction of pain scores and carries virtually no hazards.