Radiofrequency ablation is minimally invasive, target selective technique that has been in clinical use for more than 3 decades and it is effective in chronic pain condition.
Radiofrequency is a neurolytic technique that uses heat to produce controlled tissue destruction (thermocoagulation) and thus reduce pain by modulation pain transmission, without causing clinical sign of nerve damage. Pain relief can be last for many years and procedure can be repeated.
It involves the use of a special equipment to produce high frequency energy of 300 to 500 kHz similar to one use in radio-transmitter, and the current termed RF current.
Successful use of these technique requires specialized training and in depth knowledge of neural anatomy.
A high frequency current 500 kHz produced by RF generator machine apply on neural tissue through a closed circuit produce neurolysis of target nerve. With the use of this specialized generator, heat energy is created and delivered with precision to target nerves that carry pain impulses. The resulting “lesion”involves a spherical area of tissue destruction at the tip of the RF needle that can include pain-carrying nerves.
Size of lesion is determined by following factors
- Electrode tip size
- Rate of Thermal equilibrium
- Local tissue characteristics
TYPES OF RADIOFREQUENCY
- Conventional Radiofrequency
- Pulsed Radiofrequency
PROCEDURE OF RFA
Before permanent destruction of any nerve we have to check the effective pain relief by diagnostic block of the same nerve with local anaesthetics. If patient had good pain relief then we go for radiofrequency ablation with proper explanation to patients.
Radiofrequency current deliver by 27 G thermocouple probe. That probe is inserted in 22 G long insulated needle with different length and different lesion size bare area. This procedure we do under IITV, USG or CT SCAN guidance with all aseptic and antiseptic precaution in operation theatre. Before doing RF usually we check for sensory and motor nerve stimulation, to prevent unintentional nerve damage.