Concentration-dependent ablation of pancreatic tissue by EUS-guided ethanol injection

BackgroundEthanol is a commonly available agent and has been used to successfully and safely ablate cystic lesions of various organs.ObjectiveThe aim of this study was to determine the short-term effects of an EUS-guided injection of ethanol into the pancreas of pigs by using 2 mL ethanol, in increasing concentration of 0% to 100%.DesignSix pigs were sedated by general anesthesia, and ethanol was injected, under EUS-guidance, with a 22-gauge needle into the pancreatic tail.Main Outcome MeasurementsEnd points of this study were gross and microscopic evidence of pancreatitis and clinical tolerance. During the 7-day observational period, the animals were monitored by serum levels of amylase and lipase and by a CT on day 4.ResultsAt euthanasia, there was no pancreatic lesion in the animals that received normal saline solution or 20% ethanol. The injection of 40% to 100% ethanol led to a visible necrotic area in the pancreatic tail. By histology, the average maximal diameter of the lesions was 20.8 ± 4.3 mm. The cross-sectional area of necrosis was proportional to the concentration of ethanol (r = 0.961). CT demonstrated a localized site of nonenhancing pancreatic tissue, with an average diameter of 19.4 ± 10.5 mm; 40% to 100% ethanol. Clinically, the animals appeared to tolerate the procedure without sequelae. Serum levels of amylase and lipase were normal.ConclusionsThe EUS-guided injection of ethanol into the pig pancreas resulted in a localized concentration-dependent tissue necrosis without complications.