Dae Young Cheung

Capsule endoscopy in small bowel tumors: A multicenter Korean study

Background and Aim:  Capsule endoscopy (CE) has proven to be highly effective at detecting small bowel lesions in a variety of clinical conditions, but studies concerning the practical impact of CE on small bowel tumors are still scarce, especially in the Asian population. The aim of this study was to evaluate the diagnostic and therapeutic impact of CE in the field of small bowel tumors.

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.

Polyps in the gastrointestinal tract: discrepancy between endoscopic forceps biopsies and resected specimens

Background and Aim An endoscopic forceps biopsy (EFB) carries the risk of missing the neoplastic foci within a polyp as only a small portion of the lesion is sampled using this technique. Accordingly, the histological examination of specimens obtained by an EFB is of limited accuracy and patient management based on the histological findings is controversial. The aim of this prospective study was to determine the diagnostic concordance between an EFB and resected tissues of gastric and colon polyps. Methods Between January 2006 and October 2007, 1312 gastrointestinal polyps from 896 patients were resected in our hospital. Patients with polyps of epithelial origin of at least 8 mm in diameter and not associated with polyposis syndromes were included in the study. Polyps of nonepithelial origin were excluded. One thousand two hundred and sixty-four polyps of epithelial origin [gastric polyps (n=268) and colon polyps (n=996)] obtained from 813 patients met the inclusion criteria. All patients underwent an EFB and resection of the polyp by endoscopic mucosal resection and endoscopic submucosal dissection. Results Multiple polyps existed in 31.6% of the patients. The pathological diagnoses of resected gastric polyps were as follows: adenomas with low-grade dysplasia, 46 (17.2%); adenomas with high-grade dysplasia, 42 (15.7%); hyperplastic polyps, 126 (47.0%); chronic inflammatory polyps, 29 (10.8%); and adenocarcinomas, 25 (9.3%). The discrepancy rate between an EFB and the pathology of the resected gastric polyps was 39.2% (the Kendalls tau-b and the κ coefficient for agreement between the EFB and resected specimens of gastric polyps were 0.577 and 0.472, respectively; P value <0.001). No relationship between the size of the gastric polyp and the concordance rate was observed. The pathological diagnoses of the resected colon polyps were as follows: adenomas with low-grade dysplasia, 559 (56.1%); adenomas with high-grade dysplasia, 229 (23.0%); hyperplastic polyps, 44 (4.4%); adenocarcinomas, 53 (5.3%); and inflammatory polyps, 111 (11.1%). The discrepancy rate between the EFB and the pathology of the resected colon polyps was 39.8%. (the Kendalls tau-b and the κ coefficient for agreement between the EFB and the resected specimens of the colon polyps were 0.479 and 0.293, respectively; P value <0.001). No relationship between the size of the colon polyp and the concordance rate was observed. Conclusion Considerable discrepancies were observed in histological findings between the EFB and the resected specimens. Therefore, complete removal of the entire polyp is recommended to confirm the diagnosis, to remove precancerous lesions, and to develop an optimal management plan.

Eradication of Helicobacter pylori According to 23S Ribosomal RNA Point Mutations Associated With Clarithromycin Resistance

BACKGROUND Clarithromycin-resistant Helicobacter pylori is associated with point mutations in the 23S ribosomal RNA (rRNA) gene. METHODS A total of 1232 patients participated and were divided into 2 control groups and 1 case group. Patients in the APC control group, which consisted of 308 randomly assigned participants, were treated with standard triple therapy, consisting of amoxicillin, rabeprazole, and clarithromycin; 308 participants in the APM control group were treated with amoxicillin, rabeprazole, and metronidazole. For the 616 participants in the case group, a test for point mutations in the 23S rRNA gene of H. pylori was conducted. A total of 218 individuals in the case group received a new tailored therapy regimen, in which amoxicillin, rabeprazole, and clarithromycin were given in the absence of a mutation, whereas clarithromycin was replaced by metronidazole if the mutation was detected. RESULTS The rate of eradication of H. pylori in the tailored group was 91.2% (176/193), which was significantly higher than that in the APC (75.9% [214/282]; P < .001) and APM (79.1% [219/277]; P < .001) control groups. CONCLUSION The rate of H. pylori eradication among patients who received tailored therapy on the basis of detection of a clarithromycin resistance mutation by polymerase chain reaction was much higher than the rate among patients who received a standard triple therapy regimen. CLINICAL TRIALS REGISTRATION NCT0145303.

Risk factors for delayed post‐polypectomy hemorrhage: A case‐control study

Delayed post‐polypectomy hemorrhage is a rare but serious complication. The aim of this study was to identify risk factors for the development of delayed post‐polypectomy hemorrhage.

Concomitant therapy achieved the best eradication rate for Helicobacter pylori among various treatment strategies.

AIM To compare the Helicobacter pylori (H. pylori) eradication rate of clarithromycin-based triple therapy, metronidazole-based triple therapy, sequential therapy and concomitant therapy. METHODS A total of 680 patients infected with H. pylori were divided into 4 groups and each group was treated with a different eradication therapy. Clarithromycin-based triple therapy was applied to the first group [rabeprazole, amoxicillin and clarithromycin (PAC) group: proton pump inhibitor (PPI), amoxicillin, clarithromycin], whereas the second group was treated with metronidazole-based triple therapy [rabeprazole, amoxicillin and metronidazole (PAM) group: PPI, amoxicillin, metronidazole]. The third group was treated with rabeprazole and amoxicillin, followed by rabeprazole, clarithromycin and metronidazole (sequential group). The final group was simultaneously treated with rabeprazole, amoxicillin clarithromycin and metronidazole (concomitant therapy group). In the case of a failure to eradicate H. pylori, second-line quadruple and third-line eradication therapies were administered. RESULTS The per protocol (PP) analysis was performed on 143, 139, 141 and 143 patients in the PAC, PAM, sequential and concomitant groups, respectively. We excluded patients who did not receive a C(13)-urea breath test (22, 20, 23 and 22 patients, respectively) and patients with less than an 80% compliance level (5, 11, 6 and 5 patients, respectively). The eradication rates were 76.2% (109/143) in the PAC group, 84.2% (117/139) in the PAM group, 84.4% (119/141) in the sequential group and 94.4% (135/143) in the concomitant group (P = 0.0002). All 14 patients who failed second-line therapy were treated with third-line eradication therapy. Among these 14 patients, 6 infections were successfully eradicated with the third-line therapy. Both PP and intention-to-treat analysis showed an eradication rate of 42.9% (6/14). In the PAC group, 3 of 4 patients were successfully cured (3/4, 75%); 2 of 2 patients in the PAM group (2/2, 100%) and 1 of 5 patients in the sequential group (1/5, 20%) were also cured. In the concomitant group, all 3 patients failed (0/3, 0%). CONCLUSION The eradication rate for the concomitant therapy was much higher than those of the standard triple therapy or sequential therapy (ClinicalTrials.gov number NCT01922765).

Which endoscopic treatment is the best for small rectal carcinoid tumors

The incidence of rectal carcinoids is rising because of the widespread use of screening colonoscopy. Rectal carcinoids detected incidentally are usually in earlier stages at diagnosis. Rectal carcinoids estimated endoscopically as < 10 mm in diameter without atypical features and confined to the submucosal layer can be removed endoscopically. Here, we review the efficacy and safety of various endoscopic treatments for small rectal carcinoid tumors, including conventional polypectomy, endoscopic mucosal resection (EMR), cap-assisted EMR (or aspiration lumpectomy), endoscopic submucosal resection with ligating device, endoscopic submucosal dissection, and transanal endoscopic microsurgery. It is necessary to carefully choose an effective and safe primary resection method for complete histological resection.

Current Advance in Small Bowel Tumors

Small intestinal tumors are difficult challenge to gastroenterologists. The difficulty in making a diagnosis of small intestinal tumor lies in the relative inaccessibility and absence of typical presentation. New endoscopic and radiologic technologies provide clear and fine anatomical visualization of the small bowel and are approved to improve the diagnostic sensitivity and accuracy. Patients at risk of small intestinal tumors might gain a benefit from proper surveillance with this new technology. Minimally invasive therapy is now available with advance of balloon assisted enteroscopy. This review describes the general aspect of the small intestinal tumors, focusing on the new modalities for diagnosis.

Inter-observer agreement on the interpretation of capsule endoscopy findings based on capsule endoscopy structured terminology: A multicenter study by the Korean Gut Image Study Group

Abstract Objective. Capsule endoscopy (CE) is a novel investigation for the diagnosis of small-bowel disease but its interpretation is highly subjective. We studied the inter-observer agreement and accuracy of the interpretation of CE findings based on capsule endoscopy structured terminology (CEST). Material and methods. Fifty-six CE video clips were collected from eight university hospitals in South Korea and were independently reviewed by 13 gastroenterology experts and 10 trainees. All investigators recorded their findings based on CEST. To determine the accuracy of individual viewers, we defined the ‘gold standard’ as a joint review by four experts. Results. The 56 CE video clips included five normal cases, 19 cases of protruding lesions, 21 cases of depressed lesions, three cases of flat lesions, one case of abnormal mucosa, six cases with blood in the lumen, and one case of stenotic lumen. The overall mean accuracies for the experts and trainees were 74.3% ± 22.6% and 61.7% ± 25.4%, respectively. The overall accuracy for the trainee group was significantly lower than that for the expert group (P < 0.001), especially in normal, tumor, venous structure, and ulcer cases. The accuracies of the two groups varied with the CE findings. The accuracies were higher in cases with more prominent intraluminal changes (e.g. active small-bowel bleeding, ulcer, tumor, stenotic lumen). In contrast, subtle mucosal lesions, such as erosion, angioectasia, and diverticulum, had lower accuracies. The mean kappa values for the experts and trainees were 0.61 (range 0.39–0.97) and 0.46 (range 0.17–0.66), respectively. Conclusions. Our results showed that there was substantial agreement between experts and moderate agreement between trainees. In order to achieve higher accuracies and better inter-observer agreement, we need not only more experience with CE but also consensus regarding CEST terminology.

Effect of Dynamic Position Changes on Adenoma Detection During Colonoscope Withdrawal: A Randomized Controlled Multicenter Trial.

OBJECTIVES:Adequate luminal distension is essential for improving adenoma detection during colonoscope withdrawal. A few crossover studies have reported that dynamic position changes maximize luminal distension and increase adenoma detection rates (ADR). We designed a multicenter, randomized, parallel-group trial to verify the effect of dynamic position changes on colonic adenoma detection.METHODS:This study was conducted at the six hospitals of the Catholic University of Korea. Patients aged 45–80 years who underwent a colonoscopy for the first time were included. In the position change group, the position changes during colonoscope withdrawal were as follows: cecum, ascending colon, and hepatic flexure: left lateral position; transverse colon: supine position; splenic flexure, descending colon, sigmoid colon, and rectum: right lateral position. In the control group, the examinations were performed entirely in the left lateral position during colonoscope withdrawal. The primary outcome measure was the ADR, which was defined as the proportion of patients with ≥1 adenoma.RESULTS:A total of 1,072 patients were randomized into the position change group (536 patients) or the control group (536 patients). The ADR was higher in the position change group than in the control group (42.4 vs. 33.0%, P=0.002). More adenomas were detected per subject in the position change group (0.90 vs. 0.67, P=0.01). Increases in the number of adenomas were observed in examinations of the transverse colon (0.22 vs. 0.13, P=0.016) and the left colon (0.37 vs. 0.27, P=0.045). A significant increase in the ADR was observed for endoscopists with a relatively low detection rate. For endoscopists with a high detection rate, non-significant changes in the ADR were observed.CONCLUSIONS:Dynamic position changes during colonoscope withdrawal increased the ADR.