After track formation, we inserted 4.9-mm ultrathin endoscope into the abdominal cavity. The peritoneal cavity was examined, and peritoneal and liver biopsy was performed. The puncture site was closed with a single stitch. After procedure, we

observed the pigs’ general condition and abdominal wound for 2 weeks. Results: Percutaneous ultrathin flexible peritoneoscopy was successfully performed regardless of the location of the puncture site. Peritoneal and liver biopsy was also performed successfully. The mean procedure time was 20 minutes. However, formation of abdominal track is not easy using standard endoscopic equipment. There was no injury of abdominal organs. The post-procedure course was uneventful and the pigs showed normal activity and diet one day

after the procedure. Minor scar was observed on the incision site in 2 weeks after procedure. Conclusions: Percutanous ultrathin flexible peritoneoscopy is a relatively simple R788 in vivo and technically feasible method. However, to ensure safety of use on human, dedicated accessories for fascial dilation should be developed. BA HOLT,1 V JAYASEKERAN,1 F FAHRTASH-BAHIN,1 R SONSON,1 EY LEE,1 SJ WILLIAMS,1 RV LORD,2 MJ BOURKE1 1Department of Gastroenterology and Hepatology, Westmead Hospital, Sydney, Australia, 2Department of Upper Gastrointestinal Surgery, St Vincent’s Hospital, Ruxolitinib order Sydney, Australia Introduction: Complete excision is the gold standard for mucosal neoplasia of the gastrointestinal tract. It has the advantages of complete histology and the

clinical certainty of total excision. Complete Barretts Excision (CBE) is limited by stricture formation and technical difficulties with ≥2 stage resection. Temporary stenting MCE to avoid stricture may allow single session CBE without stricture in short segment disease. Patients and Methods: A single centre open label feasibility study of single-stage CBE and temporary stent insertion for circumferential Barretts (< C3 < M5) with high grade dysplasia (HGD) or intramucosal adenocarcinoma (IMC) was performed (NCT01554280), with recruitment over 6 months to achieve full enrolment of 12 stented patients. If invasive cancer was suspected endoscopically, staging by prior focal endoscopic mucosal resection (EMR) was performed. CBE by multiband mucosectomy with same day discharge was done 2 weeks later. An anti-migration covered self-expanding metal stent (NITI-S, Taewoong Medical, Korea) was inserted 10 days post-CBE, and removed at 8 weeks (Figure 1). Surveillance endoscopy was performed 3, 6 and 12-months post-CBE, and oesophageal dilations as required. Primary outcome measure was complete endoscopic and histological elimination of Barrett's mucosa. Results: 28 patients consented (14 excluded: 2 cancer, 7 C0 or >C3). 14 patients had CBE (12M; mean age 67 yrs), with initial staging EMR in 9. Median Barrett’s length was C1M3. Pre-EMR histology showed IMC 3 and HGD 11.