OC.04.2 DIAGNOSTIC ACCURACY OF RECTAL ENDOSCOPIC ULTRASONOGRAPHY TO DIAGNOSE DEEP PELVIC ENDOMETRIOSIS: EXPERIENCE FROM TWO REFERRAL GASTROENTEROLOGY UNITS

Abstract

Background and aim: Intraoperatory radiofrequency ablation (RFA) of pancreas cancer has <8% complication rate.The ultrasound (EUS)-guided laser ablation might reduce risk because it is less invasive and able to discriminate the intervening vessels. Laser ablation (LA) performed with a neodymium:yttrium-aluminum garnet (Nd:YAG) laser can achieve a high rate of complete tissue necrosis and has been applied as a minimally invasive, palliative therapy in hepatic and thyroid lesions. In a previous study we assessed the feasibility of EUS Nd:YAG LA on normal pancreatic tissue performed in-vivo in a porcine model. Aims is to confirm the feasibility and to evaluate the safety and the efficacy of EUS Nd:YAG LA on normal pancreatic tissue of in-vivo porcine model. Material and methods: Six healthy farm swines, weighted 40-50 kg, underwent pancreas LA under EUS control during general anaesthesia. Pancreatic gland was punctured with a 19-gauge needle through transgastric approach. A 1.064-nm wavelenght Nd:YAG laser was used. Output power of 2 and 3 W with a total delivered energy of 1000 J was supplied in continuous mode, as used in our previous pilot study. Serum levels of amylase, lipase and transaminase were obtained at baseline, after three hours of the endoscopic treatment, and before the euthanizing of the animals. After the endoscopic treatment the animals were observed for clinical signs of pancreatitis (loss of appetite, altered consciousness and irritability). After 1 month the animals were sedated and then euthanized. The EUS-LA target organ was excised and placed in formalin. Histological examination of the specimens was performed by a single pathologist. Results: All pancreatic specimens showed histological signs of coagulative necrosis. The ablation volume ranged from a mean of 357 to 590 mm3. No histochemical signs of pancreatitis were found at pathologic examination. All the pigs survived at 1 month. During the follow-up no pigs showed clinical signs of pancreatitis and biochemical parameters were normal. No other complications were detected at necropsy. Conclusions: EUS-guided Nd:YAG LA of pancreas performed in vivo in a porcine model is feasible and safe. Nd:YAG laser creates a time-dependent ablation volume. Furthermore other studies are needed to apply this mini-invasive approach to human pancreatic lesions. OC.04.2