Yong Sung Choi

Prevalence and risk factors of Barrett's esophagus in Korea.

Background and Aim:u2002 Barrett’s esophagus (BE) is diagnosed when specialized intestinal metaplasia (SIM) is detected histologically in endoscopically suspected columnar‐lined esophagus (CLE). It is a premalignant condition and plays a pivotal role in the development of esophageal adenocarcinoma. It has traditionally been believed to affect Asians less frequently. The aim of this study was to determine the prevalence of BE and possible associated risk factors in Korea.

Effect of balloon-occluded retrograde transvenous obliteration on the natural history of coexisting esophageal varices.

Background and Aims Balloon-occluded retrograde transvenous obliteration (BRTO) provides an effective mean of controlling gastric variceal (GV) bleeding; however, increased portal pressure after the obliteration of gastrorenal shunts may lead to a worsening and subsequent rupture of esophageal varices (EV). The aim of this study was to determine whether the natural history of coexisting EV is affected by BRTO. Methods Two hundred thirty-seven patients with gastric varices and no history of EV or GV bleeding at the time of diagnosis were included. Clinical, laboratory, and endoscopic features were compared between 25 patients who underwent BRTO due to GV bleeding (BRTO group) and 198 patients who never experience GV bleeding (control group) during follow-up. The incidences of EV bleeding were evaluated and compared between these 2 groups. Results The BRTO and control groups were not significantly different with respect to baseline characteristics including age, sex, etiologies of cirrhosis, hepatic function, and the classification or extent of EV and GV. During follow-up (median 48u2009mo), the overall incidence of first EV bleeding in the patients with fundal varices was significantly higher in the BRTO group (P=0.04). The incidences of EV bleeding were not different at 1 or 3 years (10.1% vs. 12.9%, P=0.32 and 39.3% vs. 38.4%, P=0.57), but became significantly higher in the BRTO group at 5 (72.2% vs. 48.5%, P=0.02) and 7 years (90.7% vs. 50.6%, P<0.01). Conclusions BRTO increased the bleeding rate of coexisting EV in the long term. Close monitoring and prophylaxis of EV bleeding may be warranted after BRTO.

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;)

The comparison of the risk factors and clinical manifestations of proximal and distal colorectal cancer.

PurposeColorectal cancers in the proximal or distal site have distinct clinical characteristics. In this study, the authors compared the risk factors of proximal and distal colorectal cancer.MethodsA 16-page questionnaire was administered to 529 patients with colorectal cancer before operation. Cancers were classified as proximal or distal relative to the splenic flexure. Of these 529 patients, 6 patients were excluded because of the presence of synchronous colorectal cancers. Data of the 523 patients were analyzed.ResultsTotal numbers of proximal and distal cancers were 123 and 400. The proportion of patients with Type 2 diabetes was significantly higher for distal cancer (Pu2009=u20090.034), whereas a greater proportion of patients with proximal cancer had a gallstone history (Pu2009=u20090.005). Multivariate analysis revealed Type 2 diabetes to be a risk factor for distal colorectal cancer (Pu2009=u20090.027) and cholelithiasis to be a risk factor for proximal cancer (Pu2009=u20090.049). The odds ratio for distal colorectal cancer among males with Type 2 diabetes was 4.1 (95 percent confidence interval, 1.4–12.1). On the other hand, a gallstone history was more associated with proximal colon cancer, especially in females (odds ratiou2009=u20095.5; 95 percent confidence interval, 1.4–20.9).ConclusionsA comparison of the risk factors of proximal and distal colorectal cancer showed that Type 2 diabetes is associated with distal colorectal cancer in males and that cholelithiasis is associated with proximal colon cancer in females.

Diagnostic utility of anti-Saccharomyces cerevisiae antibody (ASCA) and Interferon-γ assay in the differential diagnosis of Crohn's disease and intestinal tuberculosis

BACKGROUNDnDifferential diagnosis of Crohns disease (CD) from intestinal tuberculosis (ITB) is challenging. Anti-Saccharomyces cerevisiae antibody (ASCA) is a specific serological marker for CD and INF-gamma assay (QuantiFERON-TB gold test, QFT) is a good supplementary diagnostic tool for ITB. We evaluated the clinical usefulness of ASCA and QFT for differential diagnosis of CD from ITB in Korean adults.nnnMETHODSnA total of 147 patients suspected to have ITB or CD were prospectively enrolled from 13 hospitals. ASCA IgG and IgA serum titers were measured by ELISA, and the QFT test was also performed.nnnRESULTSnThirty-two of 72 (44.4%) patients with CD were ASCA positive (titer >25U) compared to 10 of 75 ITB patients (13.3%) and 3 of 20 healthy controls (15%) (p<0.01). The QFT test was positive in 7 patients with CD (9.7%) and 50 patients with ITB (66.6%) (p<0.01). In cases which ASCA positive/QFT negative, the sensitivity, specificity, positive predictive value, and negative predictive value for the diagnosis of CD were 44.4%, 96.0%, 91.4%, and 64.3%, respectively.nnnCONCLUSIONnASCA is a useful diagnostic tool for CD in Korea, where ITB is prevalent. In particular, when ASCA is combined with QFT, effective differential diagnosis of CD from ITB is possible.

Change in cross-sectional area of esophageal muscle does not correlate with the outcome of achalasia after pneumatic balloon dilatation

Background and Aim:u2002 Patients with achalasia have a thicker muscularis propria compared to normal patients. Because pneumatic balloon dilatation (PD) is an effective treatment for achalasia, the changes in the esophageal muscles after PD may predict treatment outcomes, if muscular change is of primary importance. In the present study, we aimed to observe the changes in esophageal muscle thickness following PD and assessed whether symptom relapse can be predicted on the basis of the esophageal muscle cross‐sectional area (CSA), as measured by high‐frequency intraluminal ultrasound (HFIUS).

Is aperistalsis with complete lower esophageal sphincter relaxation an early stage of classic achalasia

Background:u2002 Aperistalsis with complete lower esophageal sphinter (LES) relaxation, characterized by the complete relaxation of the LES and aperistalsis of the esophageal body on manometry, has been considered by some authors to be an early manifestation of classic achalasia, which is defined as incomplete relaxation of the LES and aperistalsis of the esophageal body. The aim of the present study was to compare the clinical features of patients with aperistalsis with complete LES relaxation, with those of patients with classic achalasia.

Natural history of gastric varices and risk factors for bleeding

BACKGROUND/AIMSnGastric varices (GV) are one of the most serious complications of portal hypertension, but there is limited information on the clinical course of GV in Korea. The aim of this study was to elucidate the natural history of GV bleeding in Korean patients.nnnMETHODSnOf 604 patients with GV diagnosed between May 1995 and May 2005 at the Samsung Medical Center, 237 patients without a history of variceal bleeding or previous intervention for varices were investigated. The cumulative incidence rates of GV bleeding, long-term survival rates, and risk factors for GV bleeding were evaluated.nnnRESULTSnThe cumulative incidence rates of GV bleeding were 4.8%, 19.9%, and 23.2% at 1, 3, and 5 years after diagnosis, respectively. The overall survival rates were 88.6%, 53.2%, and 37.2% at 1, 5, and 10 years. In the univariate analysis, fundal varices, large (F3) GV, red color sign, and poor liver function (Child-Pugh class B or C) were significant risk factors for GV bleeding. In the multivariate analysis, large GV (hazard ratio 2.49) and poor liver function (hazard ratio 3.95) were the independent risk factors.nnnCONCLUSIONSnGV bleeding was more frequent in patients with fundal varices than in patients with type 1 gastroesophageal varices, and large GV and poor liver function were risk factors for GV bleeding. Close observation and prophylaxis for variceal bleeding might be warranted in high-risk patients.

Characteristics of esophageal proper muscle in patients with non-cardiac chest pain using high-frequency intraluminal ultrasound.

It is unclear which mechanisms play a predominant role in the pathogenesis of esophageal non‐cardiac chest pain (NCCP). We aimed to examine the features of esophageal proper muscle and esophageal contractility using a high‐frequency intraluminal ultrasound (HFIUS) in patients with NCCP.