Effect of the relative position of electrode and stellate ganglion during thermal radiofrequency ablation: a simulation study

R. M. IRASTORZA; M. BOVAIRA; C. GARCÍA-VITORIA; V. MUÑOZ; E. BERJANO

INTERNATIONAL JOURNAL OF HYPERTHERMIA

INFORMA HEALTHCARE

Lugar: London; Año: 2021

0265-6736

Purpose: Stellate ganglion (SG) block by thermal radiofrequency ablation (RFA) isfrequently conducted as a therapeutic intervention for sympathetic-maintained andneuropathic pain syndromes. RFA?s partial lack of effectiveness could be partly due to theablation zone (AZ) not completely covering the SG section and therefore preventing the?cutting? of the afferent pathways. Our objective was to build a theoretical model toconduct computer simulations to assess the effect of the electrode position relative to theSG.Methods: A three-dimensional model was built including the SG and adjacent tissues(vertebrae C7-T1-T2, trachea, carotid artery and vertebral artery). RFA (90-s, 80oC) wassimulated considering a 22G-5 mm electrode. The AZ was computed using the 50oCisotherm.Results: An electrode displacement of 2 mm in any direction from the optimal position(centered on the SG) meant that the AZ did not fully cover the SG section. Likewise, SGsize considerably affected the RFA effectiveness since the AZ fully covered the section ofsmall but not large SGs.Conclusions: The findings suggest that the currently used SG RFA settings (i.e. 22G-5 mmelectrode, 90-s, 80oC) may not be appropriate due to their inability to achieve an AZ thatfully covers the SG cross section under certain circumstances, such as a large SG and non-optimal positioning of the RF electrode with respect to the SG center.