Sa1531 Endoscopic Ultrasound Guided Radiofrequency Ablation (EUS-RFA) of the Pancreas in a Porcine Model: A Novel Palliative Option?

Abstract

Sa1531 Endoscopic Ultrasound Guided Radiofrequency Ablation (EUSRFA) of the Pancreas in a Porcine Model: A Novel Palliative Option? Michel Kahaleh*, Monica Gaidhane, Ioana B. Smith, Kristi Ellen, Jeremy J. Gatesman, Nagy Habib, Patricia L. Foley, Christopher A. Moskaluk Division of Gastroenterology and Hepatology, Weill Cornell Medical College, New York, NY; University of Virginia, Charlottesville, VA; Surgery, Hammersmith Hospital, London, United Kingdom Background: Effective palliative treatments for pancreatic cancer are limited and include surgical procedures or chemotherapy. Radiofrequency ablation (RFA) uses high frequency alternating current to ablate diseased tissue and has been used as a method of treating tumors in various organs. However, the lack of well shaped probes fitting into the EUS-needle limits the size of the coagulative necrosis and its potential for clinical applications. In this study, we evaluated a prototype probe adjusted to the EUS-needle to perform EUS-RFA to permit coagulative necrosis of larger areas of the pancreas. Materials and Methods: Five Yucatan pigs underwent EUS-guided radiofrequency ablation of the head of their pancreas. Using an EUS-needle, RFA was applied with 6 mm of the probe exposed at 4 watts for 5 minutes, 5 watts for 0.9 minutes and 6 watts for 0.2 minutes. Then with 10mm of the probe exposed in the pancreas, RFA was performed at 4 watts for 4.3 minutes, 5 watts for 1.4 minutes and 6 watts for 0.8 minutes. Results: No gross abnormalities were noted during the serial sectioning of the pancreas. Only one pig showed moderate levels of pancreatitis, with involvement of 20% of the proximal pancreatic tissue. The other animals showed much lower areas of tissue damage. In 3 of the 5 pigs, the proximal pancreas showed greater levels of tissue injury than the distal pancreas, consistent with the proximity of the tissue to the procedure site. In 1 pig, there was minimal pancreatic tissue with pancreatitis in both the proximal and distal pancreas (1%) and in 1 pig, slightly more injury was seen in the distal pancreas versus the proximal pancreas (4% vs. 1%). In all tissue sections examined, there was minimal evidence of fat necrosis in intra-pancreatic and/or extra-pancreatic adipose tissue. Conclusion: EUS-guided radiofrequency ablation of the pancreatic head with the monopolar probe through a 19-gauge needle was well tolerated in 5 Yucatan pigs and with minimal amount of pancreatitis. However, its efficacy remains to be determined in further studies.