Adrenal Radiofrequency Ablation in Swine: Change in Blood Pressure and Histopathologic Analysis

To evaluate changes in blood pressure during adrenal radiofrequency ablation (RFA) and analyze histopathologic outcomes in swine adrenal glands. Animal Care Committee approval was obtained for this study. After laparotomy, a single adrenal gland was ablated from each of six animals (six RF sessions total). An internally cooled-tip RF electrode was placed along the long axis of the adrenal gland, and RF energy was applied for 10 min in each adrenal gland. Blood pressure and heart rate were monitored, and serum epinephrine, norepinephrine, and cortisol levels were measured before, during, and after RFA. Histological study was performed using hematoxylin-eosin staining. RFA was completed according to a planned protocol in all adrenal glands. Blood pressure increased to >200 mm Hg after an increase in heart rate during all six RF sessions. Mean serum epinephrine and norepinephrine levels increased significantly during RFA. However, mean cortisol levels showed no significant increase during or after RFA. Histological studies showed adrenal cell necrosis throughout the adrenal glands in all but one pig, with the mean necrosis rate being 99.1 ± 2.3% (range 94.3–100%). Adrenal RFA causes extensive adrenal cell damage and causes catecholamine-induced hypertension.