Radiofrequency Ablation / Neurolysis
This is also called RF ablation, denervation, rhizotomy, etc. It is a technique for temporarily destroying nerves for pain relief. By applying high frequency energy into nerve tissue via a needle, the tissue absorbs energy. If the energy is applied continuously, the nerve heats up to above 65 degrees C which is enough to destroy conduction through that nerve (thermocoagulation RF).
If the energy is delivered as intermittent pulses, the tissue barely heats, yet conduction of signals along the nerve is interrupted anyway (pulsed RF). RF destroys the electrical conduction along nerves for 3-18 months. It appears to cause fewer side effects (painful dysesthesias) when used on unmyelinated peripheral nerves such as those to the facet joints. It is also useful on discrete sensory cell bodies such as the dorsal root ganglia of the peripheral nerve roots and the trigeminal ganglion of the cranial nerves giving sensation to the face. In addition, sympathetic nerves are amenable to the RF procedure. These include the grey ramus communicans RF for spine compression fracture pain treatment and splanchnic nerve RF for abdominal pain.
RF procedures such as facet RF denervation as shown to the left, are preceded by a diagnostic block to insure at least 50% reduction in pain on injection of a local anesthetic into the area. Usually, the diagnostic block and the therapeutic RF procedures are performed at two separate sessions to assure accuracy.
RF procedures, except pulse RF, are usually not performed on peripheral nerves due to worsening pain afterwards being common.
In those cases, it is better to use cryoneurolysis. Alternatives to RF include laser facet denervation.Most spinal interventionists now recommend pulsed RF at 42 degrees centigrade for 120-180 seconds