What is a stellate ganglion test block?
A ganglion is a bundle of interconnected nerves that are important for pain in a certain area of the body. One such ganglion is known as the stellate ganglion and it is important in the treatment of some types of pain, for example in the neck, the shoulder, the jaw and the arm. Blocking this ganglion can help to relieve the pain. The stellate ganglion in found in the neck next to the seventh cervical vertebra and can easily be reached with a needle. Before we perform a permanent block of this ganglion we first do a test block to see if this helps to relieve your pain. In a test block of the stellate ganglion (see Figure) local anaesthetic is administered with a needle so that the ganglion can no longer pass on pain signals
Figure 1. Front view of the chest near the neck showing the red arteries (1) to the arms and the cervical vertebrae (2)
What should I be aware of before undergoing a stellate ganglion test block?
Any of the following situations should be reported to your pain specialist if he proposes a stellate ganglion test block:
- If you are pregnant: since X-ray equipment is used, pregnant women may not undergo a stellate ganglion test block and a new appointment has to be made.
- If you are ill or have a fever on the day of treatment you cannot undergo a stellate ganglion test block, in which case a new appointment will have to be made.
- If you are allergic to iodine, bandages, anaesthetics or contrast fluids, you should notify your pain specialist before the appointment for treatment is made.
- If you are taking blood thinners, you should notify that your pain specialist before the appointment for treatment is made. He will then consider whether the use of certain medications should be ceased temporarily.
How should I prepare for get a stellate ganglion test block?
- No special preparations, such as an overnight bag, are necessary because the treatment is carried out on an outpatient basis.
- You may eat before treatment and take your normal medication.
- N.B.: this does not include blood thinners, as mentioned above.
- Make sure you have someone to take you home, because you may not drive for 24 hours.
How does a stellate ganglion test block work?
- The treatment will be performed in the surgical day-care centre, where you will be asked to change into a surgical gown. This gown closes at the back.
- A nurse will escort you to the treatment room, where there is a treatment table, an X-ray machine and television monitors.
- You will be positioned on the treatment table on your back.
- The blood pressure and the amount of oxygen in your blood will be controlled during the treatment.
- A drip will be placed in your hand.
- The right place of the block is estimated with aid of fluoroscopy or Ultrasound.
- This place is marked on the skin with a felt pen.
- The area around this site is then disinfected with a cold, red liquid.
- The pain specialist covers the area with sterile drapes.
- After a local anesthetic has been applied to the skin, the pain specialist, by means of fluoroscopy (via the television monitor) or Ultrasound, will insert the needles in the correct place.
- Some contrast fluid is also injected to enable the position of the needle to be clearly visible.
- Then small electrical currents are administrated near the stellate ganglion.
- You will feel a tingling sensation.
- When you feel this, you must tell the treating pain specialist straight away, and not wait for it to become painful.
- The pain specialist will ask you where you feel the sensation and you don't have to point the place with your finger.
- By means of a special device, the pain specialist can read the distance from the needle to the ganglion.
- If the needle is in the right place the stellate ganglion test block is performed.
- In stellate ganglion test blocks small amount of local anaesthetics are injected around the stellate ganglion nerves to temporarily block the nerves.
- You will then be asked to get dressed and return to the waiting room.
- After half an hour, your pain specialist will inquire whether the stellate ganglion test block clearly reduced your pain.
- If this is not the case, you will have to make a new appointment with your own pain specialist to discuss further possible treatment options.
- If the stellate ganglion test block clearly reduced your pain, then an appointment will immediately be made at the day centre for a permanent stellate ganglion block.
What are dangers and side effects of stellate ganglion test block?
After a stellate ganglion test block, the following complications or side effects can occur:
- In very rare cases the needle can go through the membrane of the lung and a pneumothorax can occur.
- You immediately have to contact the hospital or the pain clinic and your GP for treatment.
When can I expect pain relief after the treatment?
- Afterpains can occur following a stellate ganglion test block. This may last a week but will eventually disappear.
- The numbness will last several hours and your original pain will return.