Methods: 10 Bama minipigs were divided into control group and stent group, one pig of each group died in the procedure. Every pig SCH772984 manufacturer underwent endoscope, then laryngopharyngeal and distal esophageal pH monitoring for 4 hours, and at last been taken specimens from laryngopharyngeal mucosa. We repeat this procedure after 14 days. For stent group, between the procedures, we implant stents into their esophaguses, then laryngopharyngeal and distal esophageal pH monitoring for 2 hours, at last took away stents 3 days later. Cell interspaces were analyzed by transmission electron

microscope. Results: 1) There are no LPR in control group, at begin or last; but in stent group, LPR happened when stent implanted and can be detected after taking stent at the fourteenth day. (p < 0.05). 2) There are only some GER in control group, at begin or last; but in stent group, More GER happened when stent implanted and can be detected after

taking stent away at the fourteenth day. (p < 0.05). 3) There are no difference in intercellular space and desmosomes in the control group between begin and last. But in the stent group, the intercellular space increased, and the desmosomes counts decreased. Conclusion: According to these Alvelestat mw result, an animal model of LPR was established by implanting stent, at the same time, we established an animal model of GERD. Of course, LPR destroy the Laryngopharyngeal mucosal barrier. Key Word(s): 1. Laryngopharyngeal; 2. Reflux; 3. animal model; 4. intercellular space; Presenting Author: NING ZHONG Additional Bcl-w Authors: XUETING ZHENG, FENGYAN LIU, XUEFENG LU, YANQING LI Corresponding Author: NING ZHONG Affiliations: Qilu Hospital; Qiluhospital; Qilu hospital Objective: The management of lesions adjacent to the upper gastrointestinal tract with unknown origin is challengeable. Endoscopic ultrasound guided fine needle aspiration (EUS-FNA)

is one of the emerging methods to acquire histological diagnosis. The aim of this study was to evaluate accuracy and safety of EUS-FNA for those lesions. Methods: Thirty-seven patients with lesions adjacent to the upper gastrointestinal tract with unknown origin were identified retrospectively. All underwent EUS-FNA using a 19 or 22 gauge needle, with 2–3 needle passes. Ultrasonic characteristics were assessed. EUS-FNA diagnoses were made on the basis of cytologic-histologic analysis.(Picture) The results were compared with the final surgical pathology or follow-up. Results: Most EUS-FNA (35/37, 95%) acquired adequate samples for diagnosis. In compared with the final diagnosis, the sensitivity, specificity, positive predictive value, negative predictive value of EUS-FNA in differentiating benign and malignant were 92%, 100%, 100%, and 85%, respectively. Final diagnosis confirmed the diagnoses of malignancy in 25.