findings provide new perspective that presence of Entero- coccus faecalis in intraoperative bile can be a new predictor and may be a new therapeutic target of CR-POPF. [O-1937] 90-DAY READMISSION AFTER PANCREATICODUODENECTOMY: A SINGLE TERTIARY CENTER EXPERIENCE IN KOREA DooHun Kim, YooSeok Yoon, HoSeong Han, KilHwan Kim, YoungRok Choi and SunJong Han Department of General surgery, Seoul National University Bundang Hospital, Republic of Korea Introduction: Pancreaticoduodenectomy(PD) has high rates of postoperative morbidity and readmission. Increasing reports on readmission after PD have been published from Western countries with the purpose of improving surgical quality. However, there have been rare reports on this topic from Asian countries with different healthcare system. This study aims to identify common reasons and risk factors for readmission after PD and evaluate the effect of clinical pathway on readmission in a Korean tertiary center. Method: A total of 850 patients who underwent PD were included in this retrospective study. Readmission was defined as ‘unintended readmission within 90 days after discharge’. Patient characteristics, perioperative outcomes and readmission rate were compared between before and after clinical pathway(CP). Result: The 90-day readmission rate was 10.0% (n=85). The most common reason for readmission was symptom- atic intraabdominal fluid collection (n=23). Although mean length of postoperative hospital stay was significantly shorter in the CP group (25.3 vs. 16.5 days, p < 0.001), the rate of readmission was similar in both groups (9.0% vs. 10.6%, p = 0.423). Any postoperative complications (OR 5.037, 95% CI 1.508-18.827) or severe complications ( 3 Clavien-Dindo classification IIIA) (OR 2.61, 95% CI 1.568-4.345) were significant risk factors in multivariate analysis. Conclusion: The results demonstrate that the readmission rate after PD was lower compared with published data of Western countries, while postoperative hospital stay was longer. CP markedly reduced postoperative hospital stay, but it did not affect the readmission rate. Patients who experienced postoperative complications after PD are at high risk for hospital readmission. [O-1835] PATHOLOGICAL IMPACT ON THE STROMA AFTER PREOPERATIVE CHEMOTHERAPY WITH NAB- PACLITAXEL AND GEMCITABINE FOR PANCREATIC CANCER Keinosuke Ishido, Norihisa Kimura, Taiichi Wakiya, Hayato Nagase, Tadashi Odagiri and Kenichi Hakamada Department of Gastroenterological Surgery, Hirosaki Univerisity Graduate School of Medicine, Japan Introduction: The aim of this study was to investigate the pathological change of pancreatic duct adenocarcinoma induced by preoperative chemotherapy with nab-paclitaxel and gemcitabine (GnP). Method: 48 patients who underwent curative surgery for pancreatic cancer were divided into three groups as follows; GnP group, preoperative chemotherapy (PC) with GnP; GS group, PC with S-1 plus gemcitabine; Control group, without PC. The evaluation of morphological changes was performed with H.E. staining specimens regarding nuclear, cytoplasmic and stromal findings, which were scored from 0 to +3. The degree of immature fibrosis was evaluated by the stained area of alpha-SMA. The degree of mature fibrosis of the stroma was evaluated by strongly stained area of Masson’s trichrome staining. Clinical and patho- logical changes in the GnP group were investigated in comparison with those in the GS and control. Result: With regard to morphological changes after chemotherapy, nuclear and cytoplasm had no significant differences among three groups. However, with regard to stromal change, significant changes were observed in GnP group compared to other two groups. Furthermore, with regard to the area in which alpha-SMA was expressed, the stained area ratio of the GnP group was significantly smaller than other two groups. With regard to the area in which Masson’s trichrome was strongly expressed, the stained area ratio of the GnP group was significantly larger than other two groups. Conclusion: Chemotherapy with GnP induced significant decrease of immature fibrosis and a high degree of mature fibrosis of the pancreatic cancer stroma. GnP may have not only an action on pancreatic cancer cells but also may act directly on immature fibrotic cells. [O-2074] ACUTE PANCREATITIS WITH OR WITHOUT CHOLANGITIS - IMPLICATIONS ON ANTIBIOTIC PROTOCOLS Yusoff Najim 1 , Yujia Gao 2 , Mohammad Shaheryar Furqan 1 , Glenn Kunnath Bonney 2 , Alfred Wei Chieh Kow 2 , Krishnakumar Madhavan 2 and Shridhar Ganpathi Iyer 2 1 Department of Surgery, Yong Loo Lin School of Medi- cine, National University of Singapore, and 2 Department of Surgery, National University Hospital, Singapore, Singapore Introduction: Administration of antibiotics in acute pancreatitis (AP) has always been a point of contention. Current guidelines do not offer a clear pathway to initiation of antibiotics in patients without infected pancreatic ne- crosis. The aim of this study evaluate the prevalence of concomitant cholangitis in patients diagnosed with AP and the initiation of antibiotics. Method: Retrospective analysis was performed on a pro- spectively collected database. Patient who were admitted to the National University Hospital (NUH) Singapore with a diagnosis of AP from 2011 to 2014 were included in the study. Data such as patient demographics, physical exam- ination findings, laboratory results and imaging results were collected. Diagnosis of AP was determined by the HPB 2019, 21 (S2), S291eS352 S320 A-PHPBA 2019: Best Poster Abstracts