Radio frequency lesioning

What is Radio Frequency Lesioning?

This is a procedure that uses a machine (Radio frequency generator) to generate a current to interrupt pain conduction  on a semi-permanent basis. The radio frequency current can either heat the surrounding tissue around a terminal branch of the nerve, a technique called thermo-coagulation, or expose the nerve to an electrical field, a technique called pulsed radiofrequency. Either technique can diminish transmission of painful sensations from the site of pain generation to the central pain transmission sites of spinal cord and brain. Radio frequency is a widely used method for neuro-modulation of pain pathways. With this procedure, a radio frequency current is passed down an electrode, through a needle/cannula that is fully insulated except for its tip. This heats the surrounding tissue from between 42-80°C and prevents the transmission of pain signals from the area being treated.

What are Facet Joints?

Facet joints (zygapophyseal joints) are located in the back of the spine from the top of the neck (cervical spine) to the bottom of the low back (lumbar spine). The facet joints are made up of two facing surfaces from the vertebra above and below. They stabilise the spine and limit extension and rotation of the spine. There are two joints, one on each side, of the spine at every vertebral level from C1 to L5; each of these have two articulating (moving) surfaces; one surface faces upwards and the other downwards. The facet joints are surrounded by a capsule of connective tissue and contain a small amount of fluid, which lubricates the joints. The surfaces of the facet joints are coated with cartilage that allows the joints to move smoothly against each other.

 

Where and how is the procedure performed?

The procedure will take place in an x-ray theatre, to enable your doctor to place the radio frequency needles at the appropriate level for your pain. Nerves cannot be visualised by x-ray; the bones around the area of the nerves are used as landmarks and can be easily seen with x-ray. Once the needle is placed a stimulating current can be used to confrim accurate location close to the nerve branch. 

The doctor will see you prior to theatre to explain the procedue, answer any questions and obtain informed consent. An intravenous cannula wil be placed in your hand or forearm, in order to provide intravenous sedation, which is used as a routine to make the procedure more easily tolerated, but if you do not wish to have sedation this is also OK. A nurse will escort you into the theatre. Please keep your glasses, if needed, with you.

You will be asked to lie down on the x-ray table, on your front for lumbar (low back) facet joint denervation or on your back for cervical (neck) facet joint denervation. A nurse will be with you at all times and you will be able to talk to them about any aspects of the procedure as it progresses. You will be offered sedation during the procedure. The sedation used is a combination of two drugs, which act in different ways. Fentanyl is used for pain relief and midazolam is a sedative used to help you relax. The amount of sedation you require will depend on how well you tolerate the procedure. You will need to be awake enough to communicate with the doctor and nurses.

How is the procedure performed?

The doctor will place needles in your back or neck under x-ray control and the radio frequency lesioning will take place at different levels. Once the needles are in the correct position the tissues surrounding the needle tip are heated using the Radio Frequency machine. This can take between one and sevral minutes for each level. You need to be awake enough to report what you are feeling in reposnse to application of electrical current. The procedure takes about half an hour. During this time the nurse will be monitoring your heart rate, blood pressure and oxygen saturation. We will add oxygen by a facemask during the procedure.

 

Risks

What are the risks? Radiofrequncy lesioning of facet joints is considered a safe procedure. There are small risks that can occur with any needle placement such as bruising and infection. These appear to be rare. Both needle placement and radiofrequncy heating can result in nerve injury with altered sensation or motor function of the peripheral nerve. This complication, fortunately, appears to be very rare.

Benefits

This is generally considered to be a useful procedure for persistent spinal pain in the presence of facet joint inury or arthritic chnage. It has been subjected to clinical trials and the evidence is generally favourable. This does not mean that success is guaranteed in every case, however. Responses can vary from prolonged quality pain relief for many years to more modest responses for a few months up to one year. Occasionally patients do not experience significant pain relief, often because there are additional pain generation sites in the spine (lumbar disc, paravertebral muscles, for example).

What happens after the procedure?

You will be taken back to your recovery area where a nurse will monitor your progress and you will be able to rest for 30 minutes to an hour. You will then be offered something to eat or drink prior to getting up. Most patients are ready to go home an hour after the procedure is completed. You will not be able to drive yourself due to the sedation. It is advisable to take things easy on the day of the procedure. You may find that you experience some muscle soreness for a few days after the procedure and it is expected that you should experience a reduction in your pain after this time. It can take several weeks to experience the maximum pain relief, especially if there is a muscle pain component to the pain (this may need to be treated, in addition).

When should I go back to work after the procedure?

You should be able to return to work the next day. If you are experiencing some pain around the injection sites you may wish to take a further day or two off work or at least ensure that your workload is not too heavy.

If you have any further questions or anxieties relating to the procedure please do not hesitate to ask any of the staff in the Pain Clinic. Direct phone line 01798 831800.