I read with interest the case report about sacral postherpetic neuralgia and the excellent results in its treatment using the paramedial approach to the ganglion impar.1The authors included in their discussion the different approaches that have been undertaken in the past to block the ganglion impar. It was also impressive to see the double-bent needle used to achieve this block. Many practitioners have elected not to perform this block because of their impression of its complexity and technical difficulty. Unfortunately, this has led to a decrease in popularity of this effective block in pain medicine.

In the past, I described a case in which coccydynia was controlled with the blockage of the ganglion impar through the sacrococcygeal junction.2The authors briefly mentioned this technique, but I am afraid their description could be interpreted to mean that this approach is of minimal value. They state, “This approach can be useful in patients with normal anatomy but may prove challenging in patients with arthritic changes in the bones and calcification of the ligaments of the sacrum and coccyx.” I have to disagree with the authors and would like to clarify that this approach is quite simple, straightforward, and equally effective. Minimal arthritic changes occur in this area, and, if any, the bone changes seldom are major challenges with this approach. de Leon-Casasola3described the transsacrococcygeal approach as the easiest way of performing the ganglion impar block. Over the years, many practitioners have tried to simplify the approach, and many reports have been published advocating the transsacrococcygeal route for its simplicity and effectiveness.4,5 

I believe that the message we should be sending to practitioners is that ganglion impar block could be performed through an easily achieved technique under fluoroscopy and that it is effective in the management of sacral pathologies, including postherpetic neuralgia. It is discouraging to see a good intervention fade into disfavor because of the complexity of the technical aspect of its performance when a technically simple alternative is present and equally effective.

Louis Stoke VA Hospital of Cleveland, Case Western Reserve University, Cleveland, Ohio. draikabbara@yahoo.com

McAllister RK, Carpentier BW, Malkuch G: Sacral postherpetic neuralgia and successful treatment using a paramedical approach to the ganglion impar. Anesthesiology 2004; 101:1472–4
Kuthuru M, Kabbara AI, Oldenburg P, Rosenberg SK: Coccygeal pain relief after transsacrococcygeal block of the ganglion impar under fluoroscopy: A case report. Arch Phys Med Rehabil 2003; 84:E24
de Leon-Casasola OA: Critical evaluation of chemical neurolysis of the sympathetic axis for cancer pain. Cancer Control 2000; 7:142–8
Basagan Mogol E, Turker G, Kelebek Girgin N, Uckunkaya N, Sahin S: Blockade of ganglion impar through sacrococcygeal junction for cancer-related pelvic pain. Agri 2004; 16:48–53
Munir MA, Zhang J, Ahmad M: Modified needle-inside-needle technique for the ganglion impar block. Can J Anaesth 2004; 51:915–7