Yoon Tae Jeen

Trends of ulcerative colitis‐associated colorectal cancer in Korea: A KASID study

Background and Aim:  The number of patients with ulcerative colitis (UC) in Korea has increased. In addition, the number of patients with colorectal cancer (CRC) associated with UC has also increased. Therefore, this population‐based nationwide study was conducted to investigate the incidence of CRC in patients with UC in Korea and compare these results to those of studies conducted in other countries.

Comparison of the characteristics of submucosal injection solutions used in endoscopic mucosal resection

OBJECTIVE Submucosal injection is used to prevent complications, such as perforation, during endoscopic mucosal resection (EMR). Since injection of normal saline produces mucosal elevation of short duration, repeated injection is needed for extensive resection. To overcome this limitation, various submucosal injection solutions have been developed but there are few data comparing their efficacy. This study was therefore conducted to compare the physical and chemical properties and the duration of mucosal elevation of various submucosal injection solutions. MATERIAL AND METHODS A fresh transverse colon specimen acquired from a mongrel was used. Experiments were repeated four times. To compare the efficacy of mucosal elevation, 1 ml of each solution was injected into the submucosa: 0.9% NaCl, 20% mannitol, 0.1% sodium hyaluronate, 0.3% hydroxypropyl methylcellulose (HPMC), and 2% fibrinogen. Physical and chemical properties such as viscosity and osmolarity were compared. RESULTS The heights of initial mucosal elevations were 6.52+/-0.26 mm, 6.87+/-0.05 mm, 6.92+/-0.09 mm, 6.90+/-0.08 mm, and 6.90+/-0.08 mm for normal saline, mannitol, sodium hyaluronate, HPMC, and fibrinogen, respectively. Whereas injection of normal saline took about 20 min and mannitol about 30 min for the initial elevation to be reduced to more than half the initial height, it took more than 60 min for all the other agents. A correlation was found between the duration of mucosal elevation and viscosity but not with osmolarity. CONCLUSIONS The mucosal elevation lasted longer with sodium hyaluronate, HPMC, and fibrinogen than with mannitol or normal saline, and this seems to be due to the viscosity rather than the osmolarity of each solution.Objective. Submucosal injection is used to prevent complications, such as perforation, during endoscopic mucosal resection (EMR). Since injection of normal saline produces mucosal elevation of short duration, repeated injection is needed for extensive resection. To overcome this limitation, various submucosal injection solutions have been developed but there are few data comparing their efficacy. This study was therefore conducted to compare the physical and chemical properties and the duration of mucosal elevation of various submucosal injection solutions. bA fresh transverse colon specimen acquired from a mongrel was used. Experiments were repeated four times. To compare the efficacy of mucosal elevation, 1 ml of each solution was injected into the submucosa: 0.9% NaCl, 20% mannitol, 0.1% sodium hyaluronate, 0.3% hydroxypropyl methylcellulose (HPMC), and 2% fibrinogen. Physical and chemical properties such as viscosity and osmolarity were compared. b The heights of initial mucosal elevations were 6.52±0.26 mm, 6.87±0.05 mm, 6.92±0.09 mm, 6.90±0.08 mm, and 6.90±0.08 mm for normal saline, mannitol, sodium hyaluronate, HPMC, and fibrinogen, respectively. Whereas injection of normal saline took about 20 min and mannitol about 30 min for the initial elevation to be reduced to more than half the initial height, it took more than 60 min for all the other agents. A correlation was found between the duration of mucosal elevation and viscosity but not with osmolarity. Conclusions. The mucosal elevation lasted longer with sodium hyaluronate, HPMC, and fibrinogen than with mannitol or normal saline, and this seems to be due to the viscosity rather than the osmolarity of each solution.

Efficacy, safety, and predictors of response to infliximab therapy for ulcerative colitis: A Korean multicenter retrospective study

Infliximab is currently used for the treatment of moderate‐to‐severe ulcerative colitis (UC) with an inadequate response to conventional agents. The efficacy and safety of infliximab in Korean patients with UC were assessed.

Comparison of sequential and 7-, 10-, 14-d triple therapy for Helicobacter pylori infection

AIM To compare the effectiveness of sequential therapy for Helicobacter pylori (H. pylori) infection with that of triple therapy of varying durations. METHODS The 460 patients enrolled in this study had H. pylori-associated gastritis or a gastric or duodenal ulcer. After screening, H. pylori-infected patients were randomly assigned to receive either conventional triple therapy for 7, 10 or 14 d, or a new 10-d sequential therapy. Each of the 4 treatment groups included 115 patients. The outcomes of eradication therapy were assessed 4 wk after treatment by the urea breath test and histology. RESULTS The overall eradication rate was 81.0%, and eradication rates were 75.7% for 7-d conventional triple therapy, 81.9% for 10-d conventional triple therapy, 84.4% for 14-d conventional triple therapy, and 82.0% for 10-d sequential therapy. Neither intention-to-treat analysis nor per protocol analysis showed significant differences in eradication rates using sequential therapy or the standard triple therapy (P = 0.416 and P = 0.405, respectively). CONCLUSION There are no significant differences between 10-d sequential eradication therapy for H. pylori and any duration of standard triple treatment in Korean patients.

Long-term outcome of capsule endoscopy in obscure gastrointestinal bleeding: A nationwide analysis

BACKGROUND AND STUDY AIMS The clinical impact of video capsule endoscopy (VCE) in patients with obscure gastrointestinal bleeding (OGIB) remains undetermined. The aim of this study was to evaluate the long-term clinical impact of VCE in patients with OGIB using a nationwide registry. PATIENTS AND METHODS Data from 305 patients who underwent VCE for OGIB from 13 hospitals in Korea between January 2006 and March 2009 were analyzed. Prospectively collected VCE registry data were reviewed, and follow-up data were collected by chart review and telephone interviews with patients. Multivariate regression analyses using hazard ratios (HR) were performed to determine risk factors for rebleeding. RESULTS Significant findings were detected in 157 patients (51.5%). After VCE, interventional treatment was performed in 36 patients (11.8%). The overall rebleeding rate was 19.0% during a mean (±SD) follow-up of 38.7±26.4 months. Rebleeding rate did not differ by positive VCE results or application of interventional treatment. Multivariate analysis revealed that angiodysplasia (HR 1.82; 95% confidence interval [CI] 1.04-3.20; P=0.037) and duration of OGIB >3 months (HR 1.64; 95%CI 1.10-2.46; P=0.016) were independent prognostic factors associated with rebleeding. In a subgroup analysis of patients taking anticoagulants, patients who discontinued drugs after VCE showed a lower rebleeding rate than those who did not discontinue this therapy (P=0.019). CONCLUSIONS VCE did not have a significant impact on the long-term outcome of patients with OGIB. Patients with angiodysplasia on VCE or OGIB>3 months need to be closely followed even after interventional treatment. In patients who are taking anticoagulants, discontinuation of drugs is necessary in order to lower the risk of rebleeding.

Colorectal Neoplasm in Asymptomatic Average-risk Koreans: The KASID Prospective Multicenter Colonoscopy Survey

BACKGROUND/AIMS The incidence of colorectal cancer is increasing in Korea, but the epidemiology of colorectal neoplasm is not clearly defined. We aimed to elucidate the prevalence of colorectal neoplasm in average-risk Koreans and explore the underlying risk factors. METHODS A large-scale, multicenter, prospective study was conducted. Of the 19,460 subjects who underwent colonoscopy at 11 university hospitals, we analyzed 3,951 consecutive asymptomatic adults with no risk factors for colorectal cancer. RESULTS The subjects were aged 52.1+/-11.6 years (mean+/-SD) and 60.1% of them were men. The prevalences of colorectal neoplasm and advanced neoplasm were 33.3% and 2.2%, respectively. The prevalence of a neoplasm increased with age (trend: p<0.001) and was higher in males (p<0.001). The prevalence of a proximal neoplasm was higher in subjects with a distal neoplasm than in those without a distal neoplasm (11.9% vs. 5.4%, p<0.001). However, 150 (52.1%) of the 288 subjects with a proximal neoplasm had no distal neoplasm. CONCLUSIONS The overall prevalence of colorectal neoplasm in asymptomatic average-risk Koreans is comparable with that in Western countries. Being male and older are associated with a higher risk of colorectal neoplasm. Over half of proximal neoplasms are not associated with any distal sentinel lesions.

Healthy range for serum ALT and the clinical significance of "unhealthy" normal ALT levels in the Korean population

Background and Aims:  It remains unclear whether the currently‐used normal range for serum alanine aminotransferase (ALT) levels really reflects a healthy liver. The present study was conducted to evaluate the healthy range of serum ALT in the Korean adult population and to determine the clinical significance of unhealthy levels.

Current and Emerging Biologics for Ulcerative Colitis

Conventional medical treatment for ulcerative colitis can have limited efficacy or severe adverse reactions requiring additional treatment or colectomy. Hence, different biological agents that target specific immunological pathways are being investigated for treating ulcerative colitis. Anti-tumor necrosis factor (TNF) agents were the first biologics to be used for treating inflammatory bowel disease. For example, infliximab and adalimumab, which are anti-TNF agents, are being used for treating ulcerative colitis. Recently, golimumab, another anti-TNF agent, and vedolizumab, an anti-adhesion therapy, have been approved for ulcerative colitis by the U.S. Food and Drug Administration. In addition, new medications such as tofacitinib, a Janus kinase inhibitor, and etrolizumab, another anti-adhesion therapy, are emerging as therapeutic agents. Therefore, there is a need for further studies to select appropriate patient groups for these biologics and to improve the outcomes of ulcerative colitis treatment through appropriate medical usage.

Guidelines for Bowel Preparation before Video Capsule Endoscopy

The preparation for video capsule endoscopy (VCE) of the bowel suggested by manufacturers of capsule endoscopy systems consists only of a clear liquid diet and an 8-hour fast. While there is evidence for a benefit from bowel preparation for VCE, so far there is no domestic consensus on the preparation regimen in Korea. Therefore, we performed this study to recommend guidelines for bowel preparation before VCE. The guidelines on VCE were developed by the Korean Gut Image Study Group, part of the Korean Society of Gastrointestinal Endoscopy. Four key questions were selected. According to our guidelines, bowel preparation with polyethylene glycol (PEG) solution enhances small bowel visualization quality (SBVQ) and diagnostic yield (DY), but it has no effect on cecal completion rate (CR). Bowel preparation with 2 L of PEG solution is similar to that with 4 L of PEG in terms of the SBVQ, DY, and CR of VCE. Bowel preparation with fasting or PEG solution combined with simethicone enhances the SBVQ, but it does not affect the CR of VCE. Bowel preparation with prokinetics does not enhance the SBVQ, DY, or CR of VCE.

Prospective evaluation of the clinical utility of interferon-γ assay in the differential diagnosis of intestinal tuberculosis and Crohn's disease

Background: Distinguishing intestinal tuberculosis (ITB) from Crohns disease (CD) is challenging. This study prospectively evaluated the clinical utility of the QuantiFERON‐TB gold test (QFT) in the differential diagnosis of ITB and CD, and compared it with the clinical utility of the tuberculin skin test (TST). Methods: Patients with suspected ITB or CD on colonoscopic findings were enrolled from 13 hospitals in Korea between June 2007 and November 2008. A QFT and TST were performed. When the initial diagnosis was not confirmed, 2‐3 months of empiric antituberculous therapy was administered. Results: In all, 128 patients were analyzed; 64 patients had ITB and 64 patients had CD. The median age of patients with ITB was greater than the patients with CD (47 years versus 31 years, P < 0.001). The positive rate for the QFT and TST (≥10 mm) in patients with ITB was significantly higher than patients with CD (67% versus 9% and 69% versus 16%, respectively; P < 0.001). The QFT and TST had good agreement (&kgr; = 0.724, P < 0.001). The diagnostic validity of QFT in ITB had a 67% sensitivity, 90% specificity, 87% positive predictive value, and 73% negative predictive value. There was no difference in these parameters between the QFT and TST. The likelihood ratio for a positive QFT was higher than a positive TST in the diagnosis of ITB (7.1 and 4.4, respectively). Conclusions: The QFT is a limited but useful diagnostic aid in combination with the TST in the diagnosis of ITB. (Inflamm Bowel Dis 2011;)