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A ganglion impar block is an injection containing a numbing agent (anesthetic) which is injected into the ganglion impar to numb or block the nerves from sending pain signals to the brain.

Ganglion Impar Block

The aim of this treatment is to ease pain resulting from a variety of health problems that cause pain in the lower pelvis and groin.

What is ganglion Impar?


A ganglion impar is a cluster or intersection of many nerves located at the front of the sacrum. The sacrum is located at the lower part of the spine just above the tailbone.

Your brain sends information to the body through the nerves. The nerves also receive information from the other parts of your body and send it to the brain.

The nerves that transfer some types of pain signals from the lower pelvis and groin pass through the ganglion impar on their way to deliver the information to the brain.

The nerves that pass through the ganglion impar include:

  • Nerves from the lower part of the rectum
  • Nerves from the lower part of the urethra
  • Nerves from the anal region
  • Nerves from the vagina and vulva
  • Nerves from the scrotum
  • Nerves from the tailbone

Why might I need a ganglion impar block?


Ganglion impar block is usually recommended after you have tried using oral medications and other ways to relieve your pain but you’re still not experiencing any pain relief or improvements.

You might need a ganglion impar block if you have lower pelvic or groin pain caused by dysfunction or damage to organs in your lower pelvic or groin area.

Your doctor might recommend ganglion impar block if you have pain resulting from:

  • Vaginal or vulvar cancer
  • Scrotal cancer
  • Rectal or anal cancer
  • Bladder cancer

Your doctor might also recommend the treatment if you have rectal pain or pain in your tailbone.

Your doctor might also use a ganglion impar block to diagnose the cause of your pain by injecting a numbing medicine in the area to see if your experience any pain relief. It helps your doctor to pinpoint the source of your pain.

Ganglion impar block may also be used in combination with other pain medications.

How do I get ready for a ganglion impar block?


Before having a ganglion impar block, your doctor will first review your medical history. Inform your doctor if you have an infection, fever, diabetes or other recent health problems.

If you are taking any blood-thinning medicines, you may need to stop taking them for days before your treatment.

Discuss all your medications with your doctor. Inform your doctor if you have:

  • Any allergies
  • Are pregnant
  • Any negative reaction with contrast dyes, past injection procedures, anesthesia, or any other medications.

Arrange for someone that will drive you back home because you’re not allowed to drive after the injection is given. Other specific instructions will be given to you by your doctor.

What happens during a ganglion impar block?

During a ganglion impar block;

Your doctor will ask you to lie down on your stomach on a procedure table.

You may be sedated to help you relax throughout the procedure, but you will remain awake to give feedback.

Your heart rate, blood pressure, and oxygen level will be closely monitored.

Your doctor will clean the area where you will have the shot injection.

Your doctor will administer a numbing agent on the skin to numb the skin around the injection site.

Your doctor will then insert a needle into the area around your tailbone between your buttocks. The needle will be inserted until it gets to the area of the ganglion impar. Your doctor may use X-rays, CT imaging, or ultrasound to help see the direction of the needle. A small amount of contrast dye may be injected through the needle into the area to help your doctor see the area more clearly. This helps to ensure that the needle is exactly in the right spot.

Your doctor will then move the needle to a position just in front of the sacrum. This is the area where the ganglion impar is located. Your doctor will then inject the numbing medicine through the needle into the area. The numbing medicine helps numb or block the pain signals. Your doctor may also inject steroids to help reduce inflammation. In some cases, the doctor may use other medicines to temporarily damage the nerves to stop them from sending pain signals.

What happens after a ganglion impar block injection?


You will be monitored for 30 to 60 minutes after the injection to ensure that nothing goes wrong.

You may feel some pain at the injection site for a few days. This is common among many patients. You may feel immediate pain relief from the numbing medicine.

Someone or a family member should drive you home. Avoid any strenuous activities for the remaining part of the day.

You should be able to eat your normal foods and drink normally. Your doctor will inform you if you shouldn’t. Your doctor will also inform you if you should resume your normal medicines.

Call your doctor if you have any of these symptoms:

Ganglion Impar Block Symptoms

  • Severe pain
  • Weakness or numbness in your legs
  • Changes in bowel or bladder function
  • Fever
  • Signs of infection at the injection site such as redness, swelling or oozing

Does ganglion Impar block hurt?

Does ganglion Impar block hurt?

Many people have some pain at the injection site for a few days. This is common and the pain usually goes away soon after the procedure.

How long does a ganglion Impar block last?

Pain relief from ganglion impar block might last a few weeks to several months. The injection may be repeated for longer-lasting pain relief.

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