Radiofrequency is an analgesic procedure that aims to produce heat in the affected tissue to reduce or eliminate pain. This technique has been used in the Pain Unit for several years, but has been refined over the last decade, especially in its effectiveness and safety.
Types of radiofrequency
There are two types of radiofrequency:
- Conventional radiofrequency (RF): also called thermal radiofrequency, it eliminates pain by causing heat injury, by means of a low energy current with high frequencies, it raises the temperature to 80ºC to interrupt the transmission of pain.
- Pulsed radiofrequency (RFP): interrupts the current to control the temperature and suppress the heat in the tissue. The maximum temperature reached is 40-42ºC in a time of 120 seconds. Its advantage is that it is not destructive, so it may be indicated in cases where conventional radiofrequency cannot be used.
What pains does radiofrequency treat?
Radiofrequency is indicated for the following types of pain:
- In the spine: cervical, dorsal, lumbar, osteoarthritic pathology, vertebral lesions.
- Facet pain (vertebral joints).
- Pain due to osteoarthritis of the hip, knee and shoulder.
- Discogenic pain: disc herniation, sciatica.
- Pain after spinal surgery
- Pain in sacroiliac joint (between sacrum, ilium and coccyx)
- Complex regional pain syndromes with pain maintained by the sympathetic nervous system
- Essential trigeminal neuralgia
- Certain cases of migraine
- Pain in peripheral nerve territories: intercostal, suprascapular, pudendal nerve, abdominal pain, etc.
- Pain in certain painful points (trigger points).
What does radiofrequency consist of?
The procedure consists in the passage of a high frequency current through a cannula in which the temperature is only increased in the part of the tip, between 2 and 4 mm. Thus, the heat transmitted by the cannula is applied to the point to be treated, usually a sensitive nerve causing the pain, so that the transmission of this pain is interrupted. The treatment is performed under local anesthesia and sedation, so it is comfortable and painless.
Side effects of radiofrequency
If the technique is carried out in the hands of an expert and following safety advice, it has very few side effects. The procedure must be performed in an operating room to maintain asepsis (absence of germs that can cause infection), and with the certainty of seeing exactly the area where the cannula is introduced, i.e., under radiological or ultrasound control. As it is a physical technique, there are the discomforts of infiltration (due to local anesthesia and sedation, which are minimal. In the case of not controlling the insertion of the cannula, another complication could be an unwanted puncture in another structure or in a vessel and cause a hematoma.
To reduce the likelihood of complications, a safety technique is to check motor and sensory stimulation once the cannula is in the proper location and controlled radiologically. With a few questions to the patient and before proceeding to perform the radiofrequency, a stimulation is practiced in which the patient feels a tingling (paresthesia) in the area where he usually feels pain, which means that the cannula is in proper position.
Results of radiofrequency
The procedure interrupts nerve conduction, which in turn can reduce pain and other associated symptoms. About 70-80% of patients achieve a good blockade of the target nerve structure. This should relieve the part of the pain controlled by the intervened nerve. Sometimes, after treatment of one nerve, it becomes apparent that there is also pain coming from other areas. If the intervention has been successful, the result may last between 3 and 18 months, usually between 6 and 9.