What is Ganglion Impar Block?
The ganglion impar block is performed to treat pain located in the coccyx (tail bone) area of the body. This visceral and/or sympathetic neuropathic perineal pain often manifests as an indistinct and poorly localized burning sensation and a sense of urgency in the region of the ganglion impar.
Also known as the ganglion of Walther or sacroccygeal ganglion, the ganglion impar is made up of a cluster of nerve cells in front of the coccyx. The allocation of the ganglion impar also encompasses the distal rectum, perineum, anal region, distal urethra, distal third of the vagina, and the vulva or scrotum. Over-activity of cells in this region can cause chronic coccyx pain.
The ganglion impar is part of the sympathetic nervous system that is part of the autonomic nervous system that controls the involuntary activities of the body. The sympathetic nervous system is frequently associated with vascular, visceral and neuropathic pain.
How is a Ganglion Impar Block Performed?
The first documented use of the ganglion impar block was in 1990. Since that time, the procedure has been modified to enhance its effectiveness and make it more comfortable for the patient. Doctors can choose from several different approaches to the ganglion block procedure. Examples of the different techniques for ganglion impar blocks include:
- Transoccygeal joint approach
- Paramedical approach
- Paracoccygeal corkscrew approach
- Transsacrococcygeal approach
Although there are several methods of ganglion impar blocks, the transsacrococcygeal approach is the most widely used due to its effectiveness and simplicity. One recent prospective study evaluated the outcomes associated with this approach on 16 consecutive patients.
The results of the study revealed that the average duration of the procedure was just over 12 minutes and all of the patients in the study benefited from significant pain relief. Based on the evidence, the researchers in this study concluded that the transsacrococcygeal approach to the ganglion impar block procedure is “easy to perform and technically feasible.”
During a transsacrococcygeal ganglion impar block procedure, the patient is positioned face-down on an x-ray table with a pillow under the pelvis to maintain the natural curve of the spine. An IV line is also used to administer sedation. Vital signs such as blood pressure, heart rate, and breathing are monitored during the procedure.
After the skin is sterilized, a local anesthetic will be administered to the injection area. Using real-time guidance from a fluoroscopic x-ray, the doctor will inject a mixture of a numbing and steroid medication into the target nerve site. The entire procedure takes approximately 15 minutes.
Current medical literature supports the role of ganglion impar injections for visceral and/or sympathetic neuropathic perineal pain. In a study published in the American Journal of Physical Medicine & Rehabilitation, just one injection has the potential to provide 100% relief of pain in the coccyx area. The authors of this article summarized their results by stating that ganglion impar blocks are minimally invasive treatments that can provide dramatic improvement for coccydynia, a condition that is otherwise often difficult to treat.
Ganglion impar injections are considered safe, non-invasive procedures; however, as with all procedures, there is some risk of complications. Although rare, theoretical risks include bleeding, nerve damage, and paralysis. To date, there are no reports of any major side effects associated with this procedure in the current medical literature.
Conditions Related To Ganglion Impar Block
The causes of sympathetic nervous system pain are complex. Chronic perineal pain (CPP) in the ganglion impar region could be caused by a wide variety of factors. Vascular pain is frequently associated with causes such as poor blood supply to the nerves. Visceral pain could be caused by chronic pancreatitis, some non-malignant pelvic pain syndromes, upper abdominal cancer, rectal cancer, and chronic perineal cancer.
Other conditions that may cause perineal pain include failed back surgery syndrome, spinal cord malformations, and sacral postherpetic neuralgia. In some cases, perineal area pain may be caused by a secondary underlying condition, such as a urinary tract infection, sexually transmitted disease, or prostate inflammation. Consult with your primary physician to eliminate one of these other potential causes before considering a ganglion impar block.
The ganglion impar block can be beneficial for pain stemming from several organs, which include the following:
- Distal third vagina
- Distal rectum
Ganglion impar blocks are a non-invasive option for treating a variety of chronic, painful conditions. This well-established nonsurgical treatment has been the subject of numerous studies, which have all yielded favorable outcomes concerning its safety and efficacy.