Nerve Root Sleeve Injection (Transforaminal Injection)
What is a Nerve Root Sleeve Injection (NRSI)?
At each level in the spine, a nerve emerges which goes out to supply nerve impulses to various body regions, including skin, muscle and organs. The area of the nerve as it emerges is called the nerve root. Each nerve root is surrounded by a little tunnel of connective tissue called the nerve root sleeve. Inside the nerve root sleeve is continuous with the epidural space of the spine, so an injection, which places medicines inside this tunnel, is effectively a type of epidural injection. A nerve root sleeve injection places a small amount of local anaesthetic and cortisone-type medication into the nerve root sleeve.
What is the purpose of a NRSI?
Back-related leg pain (called radicular pain or sometimes sciatica) is often very effectively treated by NRSI. Most surgeons will recommend at least one is done if contemplating an operation on the nerve root called a laminectomy as the outcome can help to determine the right spinal level for the surgical decompression. Sometimes it may be all the treatment that is needed for an episode of sciatica.
How is the NRSI performed?
You lie on your front on the operating theatre table while x-rays are taken to establish where the needle should go. After a sterile preparation, local anaesthetic is used to numb the skin and superficial tissues, and then the injecting needle is passed under guidance from the x-ray. When the needle looks to be in the right position, placement in the nerve root sleeve is confirmed by putting some dye in to see it spread along the tunnel. If this doesn't look right, the needle is repositioned until the dye spreads in the right pattern.
Once the needle is confirmed to be in the right position, some diluted local anaesthetic and a highly concentrated cortisone solution are injected, a total volume of around 3ml.
We offer light sedation as part of the procedure if you would like it, though it isn't essential to the success of the injection. The sedation means you won't remember the injection but it's a long way short of a full general anaesthetic. You won't be able to drive for 24 hours after having sedation, and you will have to fast for 4 hours before you arrive.
What happens after the procedure?
You will be observed in the recovery room for 30-60 minutes and be free to leave the hospital soon after that. There can be some temporary numbness in your leg after the NRSI which can make walking a little challenging so longer observation may be required if this happens. If you have pain at the site of the injection you should use a cold pack and some paracetamol (Panadol, Herron, Panamax) or ibuprofen (Herron Blue, Nurofen) in the recommended doses for a couple of days.
You will be given a Pain Diary to record the pain levels or any other symptoms you notice over the next few days. This should be returned to Pain Matrix once completed as it helps us plan your further care and monitor how well we are doing our procedures.
In the case of numbness, which has not gone away after 24 hours, or any loss of control over bladder or bowel, you should contact Pain Matrix, or attend an Emergency Department and ask that they contact us if it is after hours.
Please make sure you have made a follow-up appointment with your Pain Specialist. You should ring Pain Matrix following your procedure if one has not already been arranged.