What are sleeve injections of a nerve root?
The vertebral column is made up of vertebrae (see number 1 in the Figure) in between which can be found the so-called intervertebral discs (number 2 in the Figure) that allow the vertebrae to move against one another. Each vertebra has two small paired joints (facet joints) with the vertebra above it (number 3 in the Figure) and two small joints with the vertebra below it (number 4 in the Figure). These facet joints can be the cause of your pain, for example as a result of osteoarthritis. There is a nerve root that emerges from between two vertebrae (number 5 in the Figure). This nerve root is important in passing on pain signals.
Figure 1. Oblique view from the back of the lumbar vertebrae with part of the pelvis (see text).
To find out which nerve root is important for the area where you feel pain, we can first perform a test block of this nerve root. This is done by anaesthetising this nerve root (number 5 in the figure) with an injection so that it can no longer pass on pain signals. Your pain specialist will know from your pain pattern and the results of the neurological tests which nerve root in the lower back is causing the radiating pain in your leg. He will therefore inject corticosteroids around the nerve root at the same time as the local anaesthetic. These drugs will remove any inflammation from around the nerve root. The nerve root injections with corticosteroids are known as sleeve injections because the drugs are injected around the nerve root in an area the shape of a sleeve.
Sleeve injections are only done in the nerve roots of the thoracic vertebrae and the lumbar vertebrae, but never in the cervical vertebrae
What should I be aware of before undergoing a sleeve injection?
Any of the following situations should be reported to your pain specialist if he proposes sleeve injections:
- If you are pregnant: since X-ray equipment is used, pregnant women may not undergo sleeve injections and a new appointment has to be made.
- If you are ill or have a fever on the day of treatment you cannot undergo sleeve injections, 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 a sleeve injection?
- 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 sleeve local injection 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.
- Depending on where the sleeve injection is to be performed, you will be positioned on the treatment table on your back or stomach.
- With the help of the X-ray machine and a metal ruler, the exact location of the sleeve injection near the nerve root will be determined.
- 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.
- In sleeve injections a small amount of local anesthetics are injected around the nerve root together with corticosteroids.
- This numbness may last for several hours, and then return to the same pain level as before the sleeve injection.
- 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 sleeve injection 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 sleeve injection clearly reduced your pain, then an appointment will immediately be made at the day centre for a PRF treatment of the nerve root.
What are dangers and side effects of sleeve injections?
- Side effects of sleeve injections may be a temporary numbness of the skin where treatment took place.
- Touching of the skin in this area can be unpleasant and painful.
- This will disappear after a few weeks.
- Sometimes an allergic reaction for the injected substances can occur.
- In case you have diabetes your blood sugar level can become deregulated.
- It is of importance to inform your pain specialist before the treatment is planned.
- After a sleeve injection your blood sugar level has to be controlled by your GP or treating internist.
- Sometimes a nerve has been hit resulting in a prolonged pain.
- You have to contact pain specialist for additional pain medication.
- In women, due to the corticosteroids, hot flashes can occur and the menstrual cycle may be become disrupted briefly.
When can I expect pain relief after the treatment?
- Afterpains can occur following a sleeve injection. This may last a week but will eventually disappear.
- The optimum results of treatment are seen after two weeks.
- Around this time, a new appointment with your pain specialist will be made.