Lumbar Cooled Radiofrequency
Lumbar zygapophyseal or “facet” joint pain accounts for 15-30% of low back pain cases in the adult population. When facet-mediated pain fails to improve with conservative treatment including medications, physical therapy, and postural re-education, interventional treatment may be indicated. Radiofrequency ablation (RFA) of the lumbar medial branch nerves can provide provides a significant improvement in pain, function, and analgesic use for 6- 24 months in individuals with facet-mediated low back pain. Radiofrequency ablation has also been shown to be a cost-effective pain management modality.
cooled radiofrequency (C-RFA)
The pain mediator in lumbar facet syndrome is the medial branch nerve of the dorsal ramus (MBN), which supplies the facet joints and multifidus muscles at each spinal segment. Thermal MBN lesioning interrupts these afferent nociceptive pathways by applying radiofrequency energy to an electrode placed at the target MBN. In contrast to conventional thermal radiofrequency ablation (T-RFA) wherein the target is heated to 80 degrees C for 90 seconds, cooled radiofrequency ablation (C-RFA) uses a constant flow of ambient water circulated through the electrode via a peristaltic pump to maintain a lower tissue temperature by creating a heat sink, but still allowing neurolysis to occur. By removing heat from tissues immediately adjacent to the electrode tip, a lower lesioning temperature is maintained, resulting in less tissue charring adjacent to the electrode and therefore less tissue impedance. The volume of tissue heated and the resultant thermal lesion size is substantially larger with C-RFA as compared to T-RFA . C-RFA lesions are spherical and project several millimeters beyond the electrode tip as compared to T-RFA, thereby increasing the probability of successful denervation of the target MBN. The lesion characteristics in C-RFA also allow the electrode to be positioned at any angle to make contact with the target neural structure. Together, these make the technique easier to perform.