With an aging population, the number of patients with difficulty swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. Long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous placement of a tube into the stomach, aided endoscopically, which may be an alternative to a nasogastric tube when enteral nutritional is required for 4 weeks or more. This paper is the first Korean clinical guideline for PEG. It was developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tubes removal for PEG based on the currently available clinical evidence.

With an aging population, the number of patients with difficulty in swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. However, the long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous placement of a tube into the stomach that is aided endoscopically and may be an alternative to a nasogastric tube when enteral nutritional is required for four weeks or more. This paper is the first Korean clinical guideline for PEG developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tube removal for PEG based on the currently available clinical evidence.

With an aging population, the number of patients with difficulty in swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. However, the long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous place­ment of a tube into the stomach that is aided endoscopically and may be an alternative to a nasogastric tube when enteral nutritional is required for four weeks or more. This paper is the first Korean clinical guideline for PEG developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tubes removal for PEG based on the currently available clinical evidence.

Purpose: This study aimed to determine the effectiveness and safety of a newly developed endovenous radiofrequency (RF) catheter compared with that of the existing RF catheter in a canine model. Methods: Seven dogs underwent ablation using 1 control catheter (ClosureFAST, CF; Covidien) and 1 experimental catheter (VENISTAR, VS; STARmed Co., Ltd.) in the femoral and cephalic veins. The ablated vein was evaluated macroscopically (2,3,5-triphenyltetrazolium chloride staining, TTC), microscopically (hematoxylin and eosin staining), and ultrasonographically. Vessel injury score was used to evaluate the ablating effect objectively. Veins from 1 dog were evaluated on the day of ablation, while in the remaining 6 dogs, the ablated veins were evaluated 2 weeks later. Results: A total of 23 veins (CF, 11 veins; VS, 12 veins) were ablated in 7 dogs. Non–TTC-stained vein wall areas were identified in all ablated veins. No significant difference was observed in the mean vessel injury score (2.54 ± 1.16 vs. 2.42 ± 1.13, P = 0.656) and the mean vessel wall thickness (0.32 ± 0.03 mm vs. 0.31 ± 0.05 mm, P = 0.212) between CF and VS. There was no blood flow in all veins ablated with VS, whereas there was remaining blood flow in 1 vein ablated with CF. Perivenous complication was not observed. Conclusion Endovenous RF ablation using a newly developed VS RF catheter seems to provide comparable occlusion rate and degree of vein wall injury without perivenous adverse events compared to the most commonly used RF catheter (CF).

Patients with inflammatory bowel disease (IBD) are at risk for extraintestinal manifestations (EIM) over the course of their disease. As EIMs can involve nearly every organ, and strongly influence the quality of life, early recognition and adequate treatment are necessary to prevent severe morbidity and mortality in affected patients. Pyoderma gangrenosum is a highly severe and debilitating skin condition that occurs in 1% to 10% of ulcerative colitis (UC) patients. Thromboembolic events are also serious EIMs and usually present as deep vein thromboses in the legs or as pulmonary embolisms. A 19-year-old woman presented with bloody diarrhea lasting for 3 months and deep ulceration on the right foot. She was diagnosed with UC. The patient's skin lesions did not improve with intravenous corticosteroids and oral mesalazine. After she was started on infliximab, we observed rapid resolution of the skin lesions. She continued to complain of mild dyspnea while in the hospital. Computed tomography performed using the thromboembolism protocol revealed pulmonary thromboembolism and deep venous thrombosis. The patient underwent anticoagulant therapy with low-molecular-weight heparin, and her dyspnea gradually improved. Anticoagulation was continued with warfarin. It is rare for IBD patients to have multiple EIMs; however, this case demonstrates that multiple EIMs are a possible presentation in UC and underscores the importance of a meticulous clinical examination and adequate evaluation in the management of IBD patients presenting with EIMs.

Background/Aims: The prospective Crohn’s Disease Clinical Network and Cohort Study is a nationwide multicenter cohort study of patients with Crohn’s disease (CD) in Korea, aiming to prospectively investigate the clinical features and long-term prognosis associated with CD. Methods: Patients diagnosed with CD between January 2009 and September 2019 were prospectively enrolled. They were divided into two cohorts according to the year of diagnosis: cohort 1 (diagnosed between 2009 and 2011) versus cohort 2 (between 2012 and 2019). Results: A total of 1,175 patients were included, and the median follow-up duration was 68 months (interquartile range, 39.0 to 91.0 months). The treatment-free durations for thiopurines (p<0.001) and anti-tumor necrosis factor agents (p=0.018) of cohort 2 were shorter than those of cohort 1. Among 887 patients with B1 behavior at diagnosis, 149 patients (16.8%) progressed to either B2 or B3 behavior during follow-up. Early use of thiopurine was associated with a reduced risk of behavioral progression (adjusted hazard ratio [aHR], 0.69; 95% confidence interval [CI], 0.50 to 0.90), and family history of inflammatory bowel disease was associated with an increased risk of behavioral progression (aHR, 2.29; 95% CI, 1.16 to 4.50). One hundred forty-one patients (12.0%) underwent intestinal resection, and the intestinal resection-free survival time was significantly longer in cohort 2 than in cohort 1 (p=0.003). The early use of thiopurines (aHR, 0.35;95% CI, 0.23 to 0.51) was independently associated with a reduced risk of intestinal resection. Conclusions The prognosis of CD in Korea appears to have improved over time, as evidenced by the decreasing intestinal resection rate. Early use of thiopurines was associated with an improved prognosis represented by a reduced risk of intestinal resection.

Background: This study aimed to evaluate the diagnostic performance of the STANDARD F Influenza A/B FIA test (SD Biosensor Inc., Korea) for the rapid detection of influenza A virus in comparison with the Sofia Influenza A+B FIA (Quidel Corp., USA) and SD BIOLINE Influenza Ag A/B/A(H1N1) (Standard Diagnostic, Inc., Korea) tests. Methods: A total of 227 non-duplicated nasopharyngeal aspirates submitted for real-time RT-PCR analysis were included in the study. We used the three commercial tests in remnant samples from routine assays, according to the manufacturer’s instructions. We analyzed the diagnostic performance, including sensitivity and specificity, of the three tests. Results: Real-time RT-PCR analysis showed that 67 (29.5%) samples were positive and 160 (70.5%) were negative for influenza A virus, and that all the specimens were negative for influenza B. The overall sensitivity and specificity for influenza A virus detection were 50.7% and 100% for the STANDARD F, 50.7% and 100% for the Sofia, and 29.9% and 100% for the SD BIOLINE tests, respectively. The STANDARD F and SD BIOLINE tests showed negative results for influenza B virus in all specimens, whereas the Sofia test showed two false-positive results. Conclusion The STANDARD F Influenza A/B test showed a good diagnostic performance and may be useful for the rapid diagnosis of influenza A.

Background/Aims: Glecaprevir/pibrentasvir (G/P) is a combination of direct-acting antiviral agents that is an approved treatment for chronic infections by all six hepatitis C virus (HCV) genotypes. However, there are limited data on the effect of G/P in Korean patients in actual real-world settings. We evaluated the real-life effectiveness and safety of G/P at a single institution in Korea. Methods: This retrospective, observational, cohort study used sustained virologic response at 12 weeks after treatment completion (SVR12) as the primary effectiveness endpoint. Safety and tolerability were also determined. Results: We examined 267 individuals who received G/P for chronic HCV infections. There were 148 females (55.4%), and the overall median age was 63.0 years (range, 25 to 87 years). Eightythree patients (31.1%) had HCV genotype-1 and 182 (68.2%) had HCV-2. A total of 212 patients (79.4%) were HCV treatment-naïve, 200 (74.9%) received the 8-week treatment, 13 (4.9%) had received prior treatment for hepatocellular carcinoma, 37 (13.7%) had chronic kidney disease stage 3 or higher, and 10 (3.7%) were receiving dialysis. Intention to treat (ITT) analysis indicated that 256 (95.9%) achieved SVR12. A modified ITT analysis indicated that SVR12 was 97.7% (256/262). Six patients failed therapy because of posttreatment relapse. SVR12 was significantly lower in those who received prior sofosbuvir treatment (p=0.002) and those with detectable HCV RNA at week 4 (p=0.027). Seventy patients (26.2%) experienced one or more adverse events, and most of them were mild. Conclusions These real-life data indicated that G/P treatment was highly effective and well tolerated, regardless of viral genotype or patient comorbidities.

Background/Aims: Achalasia is an esophageal motor disorder that leads to functional esophageal obstruction. Food stasis and bacterial fermentation can predispose an individual to esophageal mucosal inflammation, causing multifocal dysplasia and increasing the risk of developing esophageal squamous cell carcinoma. We aimed to evaluate esophageal mucosal alterations in achalasia patients and determine clinical factors associated with the histopathological findings. Methods: From 2009 to 2013, we obtained endoscopic biopsies from the lower and middle esophagus of 22 patients with achalasia and 17 controls. Patients’ clinical data and histological severity of esophagitis were retrospectively analyzed. Additionally, immunohistochemical staining for CD3, CD20, Ki-67, and p53 was conducted. Results: The median age of achalasia patients was 49.5 years (range, 27 to 82 years), and there were nine males (40.9%). The median symptom duration was 5.8 years (range, 1 to 33.5 years), and 10 patients (45%) underwent previous treatment (nine, balloon dilation; one, botulinum toxin injection). Achalasia patients had significantly more severe esophagitis than did controls (p=0.001, lower esophagus; p=0.008, middle esophagus), and the number of CD3-positive lymphocytes exceeded that of CD20-positive lymphocytes (p<0.001). Achalasia patients also had a higher esophageal Ki-67 proliferation index (p=0.048). Although statistically nonsignificant, p53 expression was only observed in achalasia patients. There was no association between the histological severity of esophagitis and other clinicopathological findings. Conclusions Achalasia patients showed significantly severe histological esophagitis and a high Ki-67 proliferation index, indicating an increased risk of neoplastic progression. Therefore, careful endoscopic inspection is necessary for the early detection of superficial neoplasia in these patients.