There are limited data on outcomes after implantation of everolimus-eluting stents (EES) in East Asian patients with small vessel coronary lesions. A total of 1,600 patients treated with XIENCE EES (Abbott Vascular, CA, USA) were divided into the small vessel group treated with one ≤2.5 mm stent (n=119) and the non-small vessel group treated with one ≥2.75 mm stent (n=933). The primary end point was a patient-oriented composite outcome (POCO), a composite of all-cause death, myocardial infarction (MI), and any repeat revascularization at 12 months. The key secondary end point was a device-oriented composite outcome (DOCO), a composite of cardiovascular death, target-vessel MI, and target lesion revascularization at 12 months. The small vessel group was more often female, hypertensive, less likely to present with ST-elevation MI, and more often treated for the left circumflex artery, whereas the non-small vessel group more often had type B2/C lesions, underwent intravascular ultrasound, and received unfractionated heparin. In the propensity matched cohort, the mean stent diameter was 2.5±0.0 mm and 3.1±0.4 mm in the small and non-small vessel groups, respectively. Propensity-adjusted POCO at 12 months was 6.0% in the small vessel group and 4.3% in the non-small vessel group (p=0.558). There was no significant difference in DOCO at 12 months (small vessel group: 4.3% and non-small vessel group: 1.7%, p=0.270).Outcomes of XIENCE EES for small vessel disease were comparable to those for non-small vessel disease at 12-month clinical follow-up in real-world Korean patients.

Purpose: Cannulation of the major papilla is the most challenging part of endoscopic retrograde cholangiopancreatography (ERCP) for which physician-controlled wire-guided cannulation (PCWGC) and assistant-controlled wire-guided cannulation (ACWGC) are used as the cannulation techniques. PCWGC can reportedly save up to about 30% of the labor cost by reducing the number of assistants. This study aims to compare the safety and efficacy of PCWGC and ACWGC. Materials and Methods: Of the 2151 patients aged >20 years (4193 cases) who underwent ERCP at Yonsei University Medical Center between January 2015 and December 2016, 989 were included in this study. Results: Among efficacy outcomes, cannulation success rate, rate of precut sphincterotomy (PCWGC vs. ACWGC: 21.3% vs.25.9%), bile duct cannulation time (PCWGC vs. ACWGC: median 3.0 minutes vs. 3.6 minutes), and total procedure time (PCWGC vs. ACWGC: median 13.6 minutes vs. 13.1 minutes) were not significantly different. Among safety outcomes, lower rates of postERCP pancreatitis were observed with PCWGC than with ACWGC (PCWGC vs. ACWGC: 5.8% vs. 8.8%, p=0.128). Among other post-ERCP adverse events (bleeding, perforation, and cholangitis), the difference was not significant between the groups. Radiation exposure (total dose area product, PCWGC vs. ACWGC: median 1979.9 µGym2 vs. 2062.0 µGym2 , p=0.194) and ERCP cost excluding labor cost (PCWGC vs. ACWGC: $1576 vs. $1547, p=0.606) were not significantly different. Conclusion Requiring less assistants, PCWGC showed comparable efficacy and safety to ACWGC. PCWGC can be considered as an alternative option, especially in facilities lacking manpower and resources.

Background/Aims: Programmed death-ligand 1 (PD-L1) expression in tumor cells is associated with a poor biliary tract cancer (BTC) prognosis; tumor-infiltrating immune cells in the tumor microenvironment are associated with a better prognosis. The effect of PD-L1 expression on immune cells on survival is unclear. We investigated the relationship between PD-L1 expression in immune cells and BTC prognosis. Methods: PD-L1 expression was evaluated using an anti-PD-L1 22C3 mouse monoclonal primary antibody, and its relationships with clinical characteristics and prognosis were analyzed using the Cox proportional hazard model to investigate the prognostic performance of PD-L1 in BTC. Results: Among 144 analyzed cases, patients with positive PD-L1 expression in tumor cells and negative PD-L1 expression in immune cells showed poorer overall survival rates than those exhibiting other expressions (tumor cells: hazard ratio [HR]=1.023, p<0.001; immune cells: HR=0.983, p=0.021). PD-L1 expression in tumor cells was an independent predictor of poor overall survival (HR=1.024, p<0.001). In contrast, PD-L1 expression in immune cells was a predictive marker of good prognosis (HR=0.983, p=0.018). Conclusions PD-L1 expression in immune cells may be used as an independent factor to evaluate the prognosis of patients with BTC.

Purpose: Hypoxaemia is a significant adverse event during endoscopic retrograde cholangiopancreatography (ERCP) under monitored anaesthesia care (MAC); however, no model has been developed to predict hypoxaemia. We aimed to develop and compare logistic regression (LR) and machine learning (ML) models to predict hypoxaemia during ERCP under MAC. Materials and Methods: We collected patient data from our institutional ERCP database. The study population was randomly divided into training and test sets (7:3). Models were fit to training data and evaluated on unseen test data. The training set was further split into k-fold (k=5) for tuning hyperparameters, such as feature selection and early stopping. Models were trained over k loops; the i-th fold was set aside as a validation set in the i-th loop. Model performance was measured using area under the curve (AUC). Results: We identified 6114 cases of ERCP under MAC, with a total hypoxaemia rate of 5.9%. The LR model was established by combining eight variables and had a test AUC of 0.693. The ML and LR models were evaluated on 30 independent data splits. The average test AUC for LR was 0.7230, which improved to 0.7336 by adding eight more variables with an l 1 regularisation-based selection technique and ensembling the LRs and gradient boosting algorithm (GBM). The high-risk group was discriminated using the GBM ensemble model, with a sensitivity and specificity of 63.6% and 72.2%, respectively. Conclusion We established GBM ensemble model and LR model for risk prediction, which demonstrated good potential for preventing hypoxaemia during ERCP under MAC.

Background/Aims: Gallbladder cancer is fatal, but fluorescent imaging technology can facilitate timely diagnosis and improve patient outcomes. Fluorophore-conjugated insulin-like growth factor-1 receptor (IGF-1R) targeted antibodies were used to visualize gallbladder cancer in orthotopic tumor mouse models. Methods: Western blotting, flow cytometric analysis, and confocal microscopy detected the expression of IGF-1R in SNU-308, SNU-478, and SNU-1196 bile duct cancer cells. In vivo imaging of SNU-478 and SNU-1196 subcutaneous tumors and orthotopic gallbladder tumor models of SNU-478 were performed after injection with DyLight 650-conjugated IGF-1R antibody. Results: Western blotting and flow cytometric analysis showed that IGF-1R was expressed in bile duct cancer cells, and confocal microscopy demonstrated that IGF-1R antibody was able to bind to IGF-1R on the cell membrane. Fluorescent IGF-1R antibody injected into the mouse tail vein made subcutaneous tumors and orthotopic tumors become fluorescent. The intensity of fluorescence from the tumor was stronger than that from surrounding normal tissues. Histochemical examination confirmed that the tumor was located inside the gallbladder and adjacent liver parenchyma of mice. Conclusions Our study showed that a fluorescent IGF-1R-targeted antibody could help detect gallbladder tumors. Tumor-specific imaging technology can be applied to endoscopy, laparoscopy, and robotic surgery for better management of gallbladder cancer.

Background/Aims: Controversy regarding the effectiveness of neoadjuvant therapy for resectable pancreatic ductal adenocarcinoma (PDAC) still exists. Here, we aimed to identify the potential benefits of neoadjuvant therapy followed by surgery for resectable PDAC. Methods: We reviewed radiologically resectable PDAC patients who received resection with curative intent at a tertiary hospital in South Korea between January 2012 and August 2019. A total of 202 patients underwent curative resection for resectable PDAC: 167 underwent surgical resection first during this period, and 35 received neoadjuvant chemotherapy/chemoradiation therapy followed by surgery. Resectable PDAC patients were subdivided, and 1:3 propensity score matching (PSM) was performed to reduce selection bias. Results: Compared with the group that received surgery first, the group that received neoadjuvant treatment followed by surgery had significantly smaller tumors (22.0 mm vs 27.0 mm, p=0.004), a smaller proportion of patients with postoperative pathologic T stage (p=0.026), a smaller proportion of patients with lymphovascular invasion (20.0% vs 40.7%, p=0.022), and a larger proportion of patients with negative resection margins (74.3% vs 51.5%, p=0.049). After PSM, the group that received neoadjuvant therapy had a significantly longer progression-free survival than those in the group that underwent surgery first (29.6 months vs 15.1 months, p=0.002). Overall survival was not significantly different between the two groups after PSM analysis. Conclusions We observed significantly better surgical outcomes and progression-free survival with the addition of neoadjuvant therapy to the management of resectable PDAC. However, despite PSM, there was still selection bias due to the use of different regimens between the groups receiving surgery first and neoadjuvant therapy. Large homogeneous samples are needed in the future prospective studies.

Adult echinostomes having 37 collar spines collected from the intestine of Pitalah ducks in Aceh Province, Indonesia in 2018 were morphologically and molecularly determined to be Echinostoma miyagawai Ishii, 1932 (Digenea: Echinostomatidae). Among 20 ducks examined, 7 (35.0%) were found to be infected with this echinostome, and the number of flukes collected was 48 in total with average 6.9 (1-17) worms per duck. The adult flukes were 7.2 (6.1-8.5) mm in length and 1.2 (1.0-1.4) mm in width (pre-ovarian or testicular level) and characterized by having a head collar armed with 37 collar spines (dorsal spines arranged in 2 alternating rows), including 5 end group spines, and variable morphology of the testes, irregularly or deeply lobed (3-5 lobes) at times with horizontal extension. The eggs within the worm uterus were 93 (79-105) µm long and 62 (56-70) µm wide. These morphological features were consistent with both E. miyagawai and Echinostoma robustum, for which synonymy to each other has been raised. Sequencing of 2 mitochondrial genes, cox1 and nad1, revealed high homology with E. miyagawai (98.6-100% for cox1 and 99.0-99.8% for nad1) and also with E. robustum (99.3-99.8% for nad1) deposited in GenBank. We accepted the synonymy between the 2 species and diagnosed our flukes as E. miyagawai (syn. E. robustum) with redescription of its morphology. Further studies are required to determine the biological characteristics of E. miyagawai in Aceh Province, Indonesia, including the intermediate host and larval stage information.

In preparation for the surge of coronavirus disease 2019 (COVID-19), it is crucial to allocate medical resources efficiently for distinguishing people who remain asymptomatic until the end of the disease. Between January 27, 2020, and April 21, 2020, 517 COVID-19 cases from 13 healthcare facilities in Gyeonggi province, Korea, were identified out of which the epidemiologic and clinical information of 66 asymptomatic patients at the time of diagnosis were analyzed retrospectively. An exposure-diagnosis interval within 7 days and abnormal aspartate aminotransferase levels were identified as characteristic symptom development in asymptomatic COVID-19 patients. If asymptomatic patients without these characteristics at the time of diagnosis could be differentiated early, more medical resources could be secured for mild or moderate cases in this COVID-19 surge.

Background: Although ticagrelor is known to increase the bleeding risk compared to clopidogrel in East Asian patients, its clinical benefits in patients with acute myocardial infarction (AMI) without high bleeding risk (HBR) remains unknown. Methods: A total of 7,348 patients who underwent successful percutaneous coronary intervention (PCI) from the Korea Acute Myocardial Infarction Registry-National Institute of Health (KAMIR-NIH), between November 2011 and December 2015, were divided into two groups according to the Academic Research Consortium for HBR criteria (KAMIR-HBR, 2,469 patients; KAMIR-non HBR, 4,879 patients). We compared in-hospital major adverse cardiovascular events (MACEs, defined as a composite of cardiac death, non-fatal myocardial infarction, or stroke), and the thrombolysis in myocardial infarction (TIMI) major bleeding between ticagrelor and clopidogrel in the KAMIR-HBR and the KAMIR-non HBR groups, respectively. Results: After propensity score matching, ticagrelor had a higher incidence of in-hospital TIMI major bleeding than clopidogrel in all patients (odds ratio [OR], 1.683; 95% confidence interval [CI], 1.010–2.805; P = 0.046) and the KAMIR-HBR group (OR, 3.460; 95% CI, 1.374–8.714; P = 0.008). However, there was no significant difference in in-hospital TIMI major bleeding between ticagrelor and clopidogrel in the KAMIR-non HBR group (OR, 1.436; 95% CI, 0.722–2.855; P = 0.303). No differences were observed in the cumulative incidences of in-hospital and 6-month MACEs between ticagrelor and clopidogrel in both groups. Conclusions The bleeding risk of ticagrelor was attenuated in Korean patients with AMI without HBR. Appropriate patient selection could reduce in-hospital bleeding complications associated with ticagrelor in Korean patients with AMI who underwent successful PCI.

Background/Aims: The benefit of second-line chemotherapy (SL) after failed first-line chemotherapy (FL) in patients with advanced pancreatic cancer has not yet been established. We evaluated the clinical characteristics affecting the benefits of SL compared to best supportive care (BSC), identified the prognostic factors, and ultimately devised a model of clinical parameters to assist in making decision between SL and BSC after the failure of gemcitabine-based FL. Methods: The records of patients who received gemcitabine-based FL for advanced pancreatic cancer at Yonsei University Hospital between January 2010 and December 2015 were retrospectively reviewed. Significant clinical parameters were assessed for their potential as predictive factors. Results: SL patients received a longer duration of FL compared with BSC patients with median duration being 16.0 weeks (range, 8.0 to 26.0 weeks) and 8.0 weeks (range, 4.0 to 16.0 weeks), respectively (p<0.001). When the SL group was stratified by their modified overall survival (mOS) (longer and shorter than 6 months), we found significant differences for several clinical factors, namely, metastasis to the peritoneum (p<0.001), number of metastases (p<0.001), thrombotic events (p=0.003), and level of carbohydrate antigen 19-9 (CA19-9; p=0.011). In multivariate analysis, more than one site of metastasis, occurrence of thrombotic event during FL, and a CA19-9 level above 90 U/mL were significant independent prognostic factors for mOS in the SL group (p<0.05). When an attempt was made to devise a prognostic nomogram, Harrell’s C-index of the final prognosis prediction model was 0.62. Conclusions SL may be beneficial for patients without peritoneal metastasis or thrombotic events who have a single metastasis and a level of CA19-9 less than 90 U/mL. This prognostic nomogram can be used to predict mOS before the administration of SL after the failure of gemcitabine-based FL.