Pulsed Radiofrequency Effects on the Lumbar Dorsal Root Ganglion of the Domestic Porcine : Pilot Study

Introduction. Pulsed radiofrequency (PRF) is a percutaneous minimal invasive procedure for chronic pain management that can be used when conservative treatment methods have been ineffective. The effectiveness of PRF was demonstrated in various good quality randomized control studies, but mechanisms of action are still unclear. Aim of the Study. The aim of our study is to analyse the histological effects of PRF on the domestic porcine dorsal root ganglion (DRG), and evaluate the expression of biomarkers in gangliocytes of the subject(s). Materials and Methods. A total 3 domestic porcines were investigated. Under general anaesthesia and X-ray control, DRG PRF was performed. Four lumbar DRGs (L1, L2, L3, L4) were randomly treated. The opposite side DRGs was used as control. One month after the procedure the animal was euthanized. The lumbar region of the spine was placed in 10% formaldehyde for a month. After this fixation DRG samples were prepared for slide analysis. They were embedded in paraffin in order to obtain 3mm thick sections, which were then cut by microtome and collected on slide glasses. Using standard immunohistochemical reactions, the materials were tinted to define biomarkers neurofilaments (NF), glial fibrillary acidic protein (GFAP), heat shock protein – 70 (Hsp-70) expression and apoptosis by transferase-mediated dUTP nick-end labeling (TUNEL) analysis. Results. The number of cells with NF (26,0 ± 3,0 vs 16,1 ± 3,3; p<0,05), GFAP (12,0 ± 1,3 vs 3,2 ± 0,9; p<0,05) and Hsp-70 (10,0 ± 1,6 vs 4,2 ± 1,0; p