What is an intervertebral disc permanent block?
An intervertebral disc is located in between two vertebrae (numbers 1 and 2 in Figure 1). This intervertebral disc is found in front of the vertebral canal (number 3 in the Figure) behind which is found the spinous process of the vertebra. The intervertebral disc is like a car tyre with an outer tyre and an inner tube. The inner tube is the inner part of the intervertebral disc (the core) that keeps the car tyre under pressure (number 1 in the Figure). Around this core there is an outer part with fibres that run in various directions that form a kind of outer tyre (number 2 in the Figure).
This outer fibrous area is also supplied with small nerves for registering pain (number 4 in the figure). These nerves are found both at the front and the back of the intervertebral disc (number 5 in the Figure) and they enter a little way into the disc.
By heating the small nerves the pain signals are blocked. Door de zenuwtjes te verwarmen kunnen zij geen pijnsignalen meer doorgegeven. This is what happens in a permanent block of the intervertebral disc.
Figure 1: Bird's-eye view of a vertebra showing the intervertebral disc, and the nerves that register pain in the intervertebral disc (see text).
What should I be aware of before undergoing an intervertebral disc permanent block?
Any of the following situations should be reported to your pain specialist if he proposes a intervertebral disc permanent block:
- If you are pregnant: since X-ray equipment is used, pregnant women may not undergo an intervertebral disc permanent 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 an intervertebral disc 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 an intervertebral disc permanent 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 an intervertebral disc permanent 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 with your stomach on the top of a cushion.
- The blood pressure and the amount of oxygen in your blood will be controlled during the treatment.
- The right place of the block is estimated with aid of fluoroscopy.
- 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), 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.
- Is the needle in the right place, the pain specialist will give a radiofrequency (RF) electrical current via the needle to block the nerves to the intervertebral disc.
- This electrical current produces heat near the nerves resulting in a block and therefore less pain.
- You will then be asked to get dressed and make an appointment at the pain clinic after six to eight weeks with your own pain specialist.
- The effect of treatment will be checked and further policy will discuss with you.
- On the day of the treatment you should slow down and is advised not to participate for 24 hours in traffic.
What are dangers and side effects of an intervertebral disc permanent block?
After an intervertebral disc permanent block, the following complications or side effects can occur:
- Sometimes an allergic reaction for the injected substances such as contrast fluid can occur.
- Sometimes a nerve has been hit resulting in a prolonged pain.
- You have to contact pain specialist for additional pain medication.
When can I expect pain relief after the treatment?
- After pains can occur following an intervertebral disc permanent block. This may last a week but will eventually disappear.
- The optimum results of treatment are seen after six to eight weeks.
- Around this time, a new appointment with your pain specialist will be made.