Radiofrequency ablation of the pancreas: Two-week follow-up in a porcine model

Objective: To determine the impact of radiofrequency ablation (RFA) in pancreas after two-week follow-up. Background: RFA is a novel treatment strategy in patients with unresectable locally advanced pancreatic cancer. The histological effect and risk of postoperative complications has not been systematically addressed in an in-vivo animal model. Methods: In a porcine model (n = 6), RFA was performed via laparotomy with previously determined optimal settings using a bipolar probe with 30 mm active length, at 30 W until a total energy of 15 KJ was administered. The probe was inserted in the pancreas at 10 mm distance from duodenum and portomesenteric vessels (PMV). RFA nearby duodenum was performed under continuous duodenal cooling using 100 ml/min saline of 5 °C. During two weeks the clinical condition was evaluated daily including blood analyses. After two weeks, total pancreatoduodenectomy was performed and the obtained tissue histopathologically assessed. Results: No mortality occurred during or after RFA. Two animals had a serum amylase increase more than threefold the pre-intervention value without clinical manifestations. Histopathologic assessment showed total ablation within the ablation zone, with loss of normal pancreatic acinar cell outlines and necrosis. In one animal, focal necrosis of duodenal submucosa was seen and in another animal focal fibrosis in the muscular layer of the superior mesenteric vein without clinical manifestations. Conclusion: No major morbidity and no mortality was seen during a period of two weeks after RFA with previously validated RFA settings including duodenal cooling and 10 mm distance to PMV. Future clinical studies should confirm safety of RFA using the settings established here.