Temperature Mapping of Cooled Radiofrequency Lesion of Human Cadaver Thoracic Facet Medial Branches

Authors:
Publisher website
Google Scholar
Abstract
Objectives Thoracic facet joint pain constitutes 34% to 48% of chronic thoracic spinal pain. Variable medial branch paths in the thoracic region, particularly at branches T5 to T8 levels, make the clinical outcomes of conventional radiofrequency (RF) ablation inconsistent. The internally cooled-RF electrodes can achieve ablation of larger tissue volumes and may increase the probability of capturing the targeted thoracic medial branch nerves. Methods We thus investigated the thermal profile achieved by cooled RF in the thoracic tissue in 2 fresh intact human cadavers in prone position. An 18-gauge cooled-RF electrode with 3.5 or 5.5 mm active tip was positioned at the superolateral aspect of the thoracic transverse process to create a lesion (150 s, set temperature 60°C). Two thermocouple arrays were placed parallel to the electrode to capture temperature data in the surrounding tissue. Calibrated fluoroscopy imaging in anterior-posterior and lateral views was used to calculate thermocouple distances from the electrode. Results The 3.5 mm active electrode raised the temperatures to 74°C, 54°C, 43°C, 33°C, 27°C, and 36°C at distances of 1, 2, 3, 4, 5, and 6 mm, respectively, whereas the 5.5 mm active electrode achieved temperatures of 49°C, 55°C, 62°C, 63°C, and 35°C at distances of 2, 3, 4, 5, and 6 mm, respectively. Thus, the 5.5 mm active electrode is able to achieve temperatures sufficient for neural tissue ablation within a 5 mm radius tissue volume. Discussion Cooled RF may offer an effective and reliable method for treating thoracic facet joint pain despite of the variable anatomic paths of the thoracic facet medial branches.

This publication has 16 references indexed in Scilit: