Radiofrequency lesioning techniques in the management of chronic pain

Radiofrequency lesioning of nerves is a procedure that may be used to reduce certain kinds of chronic pain by preventing transmission of pain signals. It is a procedure in which a portion of nerve tissue is either heated by the application of current via an electrode to a temperature not exceeding 85°C alongside the nerve (this procedure is sometimes called radiofrequency ablation) or by using a pulsed current flow, the effect of which is thought to be due to an electrical field causing a change in cellular behaviour distal to the electrode (pulsed radiofrequency) as temperatures are controlled by a thermocouple to not exceed 45°C. These interventions cause a long-lasting interruption in that sensory nerve or pathway and potentially reduce pain in that area. Application of these techniques has been studied and shown to be of use in several areas. These include the zygapophysial (facet) joint, dorsal root ganglion, sacro-iliac joint, sympathetic nervous system and trigeminal ganglion. The most recent use of radiofrequency is ‘percutaneous nucleoplasty’ or Coblation™. This is an effective treatment for symptomatic intervertebral disc prolapse. Radiofrequency has many advantages, including a lesion size that can be accurately controlled and a recovery which is rapid and usually uneventful. This then allows the procedures to be performed as a day case. Patients need to be aware that this is not a curative procedure and it is of little use in those patients who have multiple pain sites. When used appropriately and after the patient has been shown to respond adequately to diagnostic blocks, radiofrequency and pulsed radiofrequency have been shown to be effective and worthwhile treatments.