Abstract: BACKGROUND: Radiofrequency ablation (RFA) temperatures reaching 45°C in
adjacent tissues are cytotoxic to the spinal cord, nerves and surrounding
tissues. OBJECTIVE: This study compares different RFA electrodes with regard to the
temperature distribution during ablation of spinal metastases. METHODS: In vitro experimental study in isolated lumbar vertebrae of a human
cadaveric spine. The temperature distribution of RFA electrodes was measured
during ablation in human cadaveric lumbar vertebrae containing a simulated
vertebral body lesion. The analysis compared a novel bipolar RFA electrode
with two conventional monopolar RFA electrodes. A vertebral metastasis model
was prepared in eight lumbar vertebrae for each electrode. Differences
between the electrodes were evaluated with a one-way ANOVA. RESULTS: The lowest temperature at the thermocouples adjacent to the
simulated lesion was achieved when using the bipolar RFA electrode (46.4 ± 3.3°C), but temperature difference to the monopolar RFA
electrodes was not significant. In the neural foramen and epidural space of
lumbar vertebrae the maximal temperature measured when using the bipolar RFA
electrode was 37.0 ± 0°C and 37.3 ± 0.7°C, which was
significantly lower than during ablation via either of the monopolar RFA
electrodes (p ≤ 0.001). CONCLUSIONS: Temperatures in areas of adjacent tissue during RFA using a
specific for spinal ablation designed electrode with integrated
thermocouples were significantly lower compared to other electrodes,
potentially reducing temperature related risks during ablation.
