The ganglion impar block is performed to treat pain located in the coccyx region of the body. The ganglion impar is a group of nerve cells located in front of the coccyx. Tis nerve bundle is part of the sympathetic nervous system, and these nerves control involuntary body activities. These nerves supply the distal rectum, urethra, vagina, scrotum, and perineum.
This block is used for visceral and/or sympathetic neuropathic perineal pain, which is poorly localized and perceived as a burning sensation.
The ganglion impar block is used to treat chronic perineal pain, which is caused by many conditions. Vascular pain is the result of poor blood supply to the nerves, whereas visceral pain is caused from upper abdominal cancer, chronic pancreatitis, non-malignant pelvic pain, rectal cancer, and perineal cancer. Other conditions that cause pain in the perineal region are sacral postherpetic neuralgia, spinal cord malformations, and failed back surgery syndrome.
The ganglion impar block can be performed via several approaches, including the transcoccygeal joint approach, the paracoccygeal corkscrew approach, the paramedical approach, and the transsacrococcygeal approach. The transsacrococcygeal approach is the most commonly used method, because it is simple and effective.
Before you have the ganglion impar block, the doctor will go over your medical history and discuss your current medications. Because blood-thinning agents can cause excessive bleeding, the doctor may have you hold these for a few days prior to the procedure. In addition, a mild sedative is used, so please do not not eat or drink at least six hours before the procedure and bring someone to drive you home. A nurse will explain the risks and benefits and have you sign a consent form at the medical center.
The ganglion impar block via the transsacrococcygeal approach involves positioning the patient on his/her stomach with pillows under the pelvis. The nurse will monitor vital signs (heart rate, breathing, and blood pressure), and an IV catheter is inserted to administer mild sedation. Onceskin has been cleansed usingan antiseptic, it is be numbed with a local anesthetic. Using real-time fluoroscopy, the doctor will insert the needle in position near the ganglion impar.
When the ganglion impar block procedure is done, you will be monitored by a nurse for around 20-30 minutes. You should take it easy for the dayand may return to regular activities in 2-3 days. If there is soreness at the injection site, we recommend using an ice pack for 20-minute intervals 4-5 times each day.
The ganglion impar block is a safe, minimally invasive procedure. However, as with most procedure, a few risks must be considered. While rare, risks include nerve damage, bleeding, infection, and trauma to blood vessels.
A recent clinical study found that CT-guided ganglion impar blocks offered pain relief for 75% of patients. In addition, of those in the study, 37% reported complete pain relief. The majority of patients had some response, which lasted for 3-6 months. In another study of patients with chronic perineal pain, the ganglion impar block reduced pain scores by 50%, with significant pain relief at the two-month follow-up.