Early detection of colorectal cancer based on presence of methylated syndecan-2 (SDC2) in stool DNA.

BACKGROUND: Colorectal cancer (CRC) screening can effectively reduce disease-related mortality by detecting CRC at earlier stages. We have previously demonstrated that the presence of SDC2 methylation in stool DNA is significantly associated with the occurrence of CRC regardless of clinical stage. The aim of this study was to evaluate the clinical performance of stool DNA-based SDC2 methylation test for CRC. METHODS: Aberrant SDC2 methylation in stool-derived DNA was measured by linear target enrichment (LTE)-quantitative methylation-specific real-time PCR (qMSP). Duplicate reactions of meSDC2 LTE-qMSP test were performed for stool samples obtained from CRC patients representing all stages (0-IV) and asymptomatic individuals who were subsequently underwent colonoscopy examination. To determine the diagnostic value of test in CRC and control groups, sensitivity and specificity were evaluated by receiver operating characteristic curve analysis. RESULTS: Of 585 subjects who could be evaluated, 245 had CRC, 44 had various sizes of adenomatous polyps, and 245 had negative colonoscopy results. Stool DNA-based meSDC2 LTE-qMSP showed an overall sensitivity of 90.2% with AUC of 0.902 in detecting CRC (0-IV) not associated with tumor stage, location, sex, or age (P > 0.05), with a specificity of 90.2%. Sensitivity for detecting early stages (0-II) was 89.1% (114/128). This test also detected 66.7% (2/3) and 24.4% (10/41) of advanced and non-advanced adenomas, respectively. CONCLUSIONS: Results of this study validated the capability of stool DNA based-SDC2 methylation test by LTE-qMSP for early detection of CRC patient with high specificity. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03146520 , Registered 10 May 2017, Retrospectively registered; however, control arm was prospectively registered.

Identification of genetic susceptibility loci for intestinal Behçet's disease.

Several recent genome-wide association studies (GWAS) identified susceptibility loci/genes for Behçet's disease (BD). However, no study has specifically investigated the genetic susceptibility loci associated with intestinal involvement in BD. We aimed to identify distinctive genetic susceptibility loci/genes associated with intestinal involvement in BD and determine their roles in intestinal inflammation as well as their interactions with genes involved in inflammatory bowel disease (IBD). GWAS and validation studies showed intestinal BD-specific associations with an NAALADL2 gene locus (rs3914501, P = 3.8 × 10-4) and a YIPF7 gene locus (rs6838327, P = 3.5 × 10-4). Validation, haplotype, and pathway analyses showed distinct genetic architectures between intestinal BD and BD without intestinal involvement. Furthermore, network analysis revealed shared pathogenic pathways between intestinal BD and IBD. Gene functional analyses indicated that down-regulation of NAALADL2 and YIPF7 expression was associated with exacerbating intestinal inflammatory responses both in vitro and in vivo. Our results provide new insights into intestinal BD-specific genetic variations, which represents a distinct pathway from BD without intestinal involvement. Functional consequences of the intestinal BD-specific NAALADL2 and YIPF7 expression patterns proved a suggestive association with intestinal inflammation risk, which warrants further validation.

Accuracy of three different fecal calprotectin tests in the diagnosis of inflammatory bowel disease.

BACKGROUND/AIMS: Several studies have found that the measurement of fecal calprotectin is useful for the early diagnosis of inflammatory bowel disease (IBD). We compared the effectiveness of three different fecal calprotectin kits for initial diagnosis in patients with suspected IBD. METHODS: We enrolled 31 patients with IBD (18 Crohn's disease [CD], 11 ulcerative colitis [UC], and two intestinal Behçet's disease), five with irritable bowel syndrome (IBS), and five with other colitis (four infectious colitis and one intestinal tuberculosis). Diagnosis was based on clinical, laboratory, and endoscopic examinations. Fecal samples were obtained at the first diagnosis and calprotectin levels were measured using three different kits (Quantum Blue® Calprotectin, EliA™ Calprotectin, and RIDASCREEN® Calprotectin). RESULTS: The overall accuracy for differentiating IBD from IBS or other colitis was 94% and 91%, respectively, for Quantum Blue® (cutoff, 50 µg/g); 92% and 89%, respectively, for EliA™ (cutoff, 50 µg/g); and 82% and 76%, respectively, for RIDASCREEN® (cutoff, 50 µg/g). In patients with CD, the results of Quantum Blue® Calprotectin and EliA™ Calprotectin correlated significantly with levels of the Crohn's disease activity index (Spearman's rank correlation coefficient, r=0.66 and r=0.49, respectively). In patients with UC, the results of EliA™ Calprotectin correlated significantly with the Mayo score (r=0.70). CONCLUSIONS: Fecal calprotectin measurement is useful for the identification of IBD. The overall accuracies of the three fecal calprotectin kits are comparable.

Long-Term Effects of Bone Marrow-Derived Mesenchymal Stem Cells in Dextran Sulfate Sodium-Induced Murine Chronic Colitis.

BACKGROUND/AIMS: Bone marrow-derived mesenchymal stem cells (BM-MSCs) have shown beneficial effects in experimental colitis models, but the underlying mechanisms are not fully understood. We investigated the long-term effects of BM-MSCs, particularly in mice with chronic colitis. METHODS: Chronic colitis was induced by administering 3% dextran sulfate sodium (DSS) in a series of three cycles. BMMSCs were injected intravenously into DSS-treated mice three times during the first cycle. On day 33, the therapeutic effects were evaluated with clinicopathologic profiles and histological scoring. Inflammatory mediators were measured with real-time polymerase chain reaction. RESULTS: Systemic infusion of BM-MSCs ameliorated the severity of colitis, and body weight restoration was significantly promoted in the BMMSC- treated mice. In addition, BM-MSC treatment showed a sustained beneficial effect throughout the three cycles. Microscopic examination revealed that the mice treated with BM-MSCs had fewer inflammatory infiltrates, a lesser extent of inflammation, and less crypt structure damage compared with mice with DSS-induced colitis. Anti-inflammatory cytokine levels of interleukin-10 were significantly increased in the inflamed colons of BM-MSC-treated mice compared with DSS-induced colitis mice. CONCLUSIONS: Systemic infusion of BM-MSCs at the onset of disease exerted preventive and rapid recovery effects, with long-term immunosuppressive action in mice with repeated DSS-induced chronic colitis.

HLA-C*01 is a Risk Factor for Crohn's Disease.

BACKGROUND: A dysregulated mucosal immune response to the intestinal environment in a genetically susceptible host is hypothesized to be critical to the pathogenesis of Crohn's disease (CD). Therefore, we examined CD-susceptibility genes involved in the immune response through a genome-wide association study and consecutive genotyping of human leukocyte antigens (HLAs) and killer cell immunoglobulin-like receptors. METHODS: An initial genome-wide association study was performed with 275 CD patients and 2369 controls from a Korean population. To validate the loci identified in the genome-wide association study, replication genotyping was performed in a different cohort of 242 CD patients and 1066 controls. Finally, high-resolution genotyping of HLA and killer cell immunoglobulin-like receptor was performed. RESULTS: Four susceptibility loci, a promoter region in tumor necrosis factor (ligand) superfamily member (TNFSF15) and 3 independent regions in HLAs, showed significant associations with CD. Among them, rs114985235 in the intergenic region between HLA-B and HLA-C showed the strongest association, with an increased risk of CD (P = 8.71 × 10; odds ratio, 2.25). HLA typing in this region showed HLA-C*01 to be responsible for the association of CD among 43 HLA-B and HLA-C genotypes identified in the Korean population. However, the interaction of HLA-C with killer cell immunoglobulin-like receptor had little effect on the development of CD. CONCLUSIONS: We newly identified HLA-C*01 as a prominent CD-susceptibility HLA allotype in the Korean population. In addition, these results confirm that genetic variations in immune response genes, such as HLAs and TNFSF15, are important host factors for the pathogenesis of CD.

Risk Factors for Recurrent High-Risk Polyps after the Removal of High-Risk Polyps at Initial Colonoscopy.

PURPOSE: Colonoscopic polypectomy and surveillance are important to prevent colorectal cancer and identify additional relative risk factors for adequate surveillance. In this study, we evaluated risk factors related to recurrent high-risk polyps during the surveillance of patients with high-risk polyps. MATERIALS AND METHODS: We included 434 patients who had high-risk polyps (adenoma≥10 mm, ≥3 adenomas, villous histology, or high-grade dysplasia) on the baseline colonoscopy and underwent at least one surveillance colonoscopy from 2005 to 2011 at Severance Hospital. Data regarding patient characteristics, bowel preparation and polyp size, location, number, and pathological diagnosis were retrospectively collected from medical records. Patients with recurrent high-risk polyps were compared with patients with low-risk or no polyps during surveillance. RESULTS: Patients were predominantly male (77.4%), with a mean age of 61.0±8.6 years and mean follow-up of 1.5±0.8 years. High-risk polyps recurred during surveillance colonoscopy in 51 (11.8%) patients. Results of multivariate analysis showed that male gender, poor bowel preparation, and a larger number of adenomas were independent risk factors for recurrent high-risk polyps (p=0.047, 0.01, and <0.001, respectively). Compared with high-risk polyps found during initial colonoscopy, high-risk polyps on surveillance colonoscopy had higher proportions of small adenomas, low-risk pathology, and fewer adenomas overall, but there was no difference in location. CONCLUSION: Male patients and those with poor bowel preparation for colonoscopy or higher numbers of adenomas were more likely to experience recurrent high-risk polyps.

GWAS identifies two susceptibility loci for lamotrigine-induced skin rash in patients with epilepsy.

PURPOSE: Lamotrigine (LTG)-induced maculopapular eruption (MPE) often causes treatment discontinuation and rising burdens on current healthcare systems. We conducted a genome-wide association study to identify novel susceptibility loci associated with LTG-induced MPE in patients with epilepsy. MATERIALS AND METHODS: We enrolled patients with LTG-induced MPE (n=34) and utilized the Korea Association Resource project cohort as a control group (n=1214). We explored associations between LTG-induced MPE and single nucleotide polymorphisms (SNPs) through imputation and replicated these associations in samples from 59 LTG-induced MPE cases and 98 LTG tolerant-controls. RESULTS: We found two novel SNPs associated with LTG-induced MPE: rs12668095 near CRAMP1L/TMEM204/IFT140/HN1L (P=4.89×10(-7)) and rs79007183 near TNS3 (P=3.15×10(-10)), both of which were replicated in an independent cohort. CONCLUSION: These two validated SNPs may be good candidate markers for predicting LTG-induced MPE in epilepsy patients, although further experimental validation is needed.

Correlation between soluble triggering receptor expressed on myeloid cells-1 and endoscopic activity in intestinal Behçet's disease.

PURPOSE: The serum levels of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) have recently been shown to be correlated highly with disease activity in patients with intestinal Behçet's disease (BD). However, it remains unclear whether sTREM-1 levels reflect endoscopic activity in intestinal BD. This study aimed to evaluate the correlation of sTREM-1 levels with endoscopic activity in intestinal BD. MATERIALS AND METHODS: A total of 84 patients with intestinal BD were enrolled. Endoscopic activity was compared with sTREM-1 levels as well as other laboratory findings, including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). RESULTS: sTREM-1 levels were significantly increased in intestinal BD patients compared with controls (37.98±27.09 pg/mL vs. 16.65±7.76 pg/mL, p=0.002), however, there was no difference between endoscopically quiescent and active diseases (43.53±24.95 pg/mL vs. 42.22±32.68 pg/mL, p=0.819). Moreover, serum sTREM-1 levels did not differ in terms of number, shape, depth, size, margin, or type of ulcer in patients with intestinal BD. However, mean ESR and CRP levels in patients with active disease were significantly higher than those in patients with quiescent disease (p=0.001, p<0.001, respectively). In addition, endoscopic activity scores for intestinal BD were correlated significantly with both CRP levels (γ=0.329) and ESR (γ=0.298), but not with sTREM-1 levels (γ=0.166). CONCLUSION: Unlike CRP levels and ESR, serum sTREM-1 levels were not correlated with endoscopic activity in patients with intestinal BD.

Mucosal healing predicts the long-term prognosis of intestinal Behçet's disease.

BACKGROUND: Mucosal healing (MH) has emerged as a therapeutic goal in the treatment of inflammatory bowel disease; however, little is known about the impact of MH on the prognosis of intestinal Behçet's disease (BD). AIM: We investigated whether MH could predict the prognosis of intestinal BD. METHODS: We retrospectively reviewed the medical records of 80 patients with intestinal BD who underwent colonoscopy within 3 months after clinical remission. The clinical recurrence rate according to the presence or absence of MH was evaluated using the Kaplan-Meier method and the log-rank test. In order to evaluate MH as an independent prognostic factor, a multivariate analysis using Cox proportional hazards regression model was performed including other potential factors for the relapse of intestinal BD. RESULTS: The number of patients with active ulcers at the time of clinical remission was 57 (71.3%), while 23 patients (28.7%) were experiencing MH. In the active ulcer group, 39 patients (68.4%) experienced recurrence during the follow-up period, whereas 7 patients (30.4%) recurred in the MH group. The cumulative recurrence rate was significantly higher in the active ulcer group than in the MH group (P < 0.001). A multivariate analysis identified active ulcers at the time of clinical remission as an independent predictive factor for relapse. CONCLUSION: Our study demonstrates that MH is an independent factor predictive of long-term prognosis of intestinal BD. MH might be the ultimate therapeutic goal in the treatment of intestinal BD.

Does magnifying narrow-band imaging or magnifying chromoendoscopy help experienced endoscopists assess invasion depth of large sessile and flat polyps?

BACKGROUND: Distinguishing deep submucosa (SM) from superficial SM cancer in large sessile and flat colorectal polyps (>2 cm) is crucial in making the most appropriate therapeutic decision. We evaluated the additional role of magnifying narrow-band imaging (NBI) and magnifying chromoendoscopy (MCE) in assessing the depth of invasion in large sessile and flat polyps in comparison to morphological evaluation performed by experienced endoscopists. METHODS: From May 2011 to December 2011, a total of 85 large sessile and flat polyps were analyzed. Endoscopic features of the polyps were independently evaluated by experienced endoscopists. Subsequently, the polyps were observed using magnifying NBI and MCE. RESULTS: A total of 58 intramucosal lesions and 27 SM cancers (five superficial and 22 deep) were identified. The diagnostic accuracy of the experienced endoscopists, NBI, and MCE were 92.9, 90.6, and 89.4 %, respectively, for deep SM cancer. In combination with NBI or MCE, the diagnostic accuracy of the experienced endoscopists did not change significantly for deep SM cancer, with an accuracy of 95.3 % for both NBI and MCE. CONCLUSIONS: Conventional colonoscopy can differentiate superficial from deep SM cancers with an accuracy of as high as 92.9 % in large sessile and flat polyps. Further diagnostic strategies are required in order to precisely assess the depth of invasion, especially in large colorectal polyps.

Folfox4 as a rescue chemotherapy for gemcitabine-refractory pancreatic cancer.

BACKGROUND/AIMS: This phase II study assessed the efficacy and safety of FOLFOX4 as a rescue therapy in patients with gemcitabine-refractory pancreatic cancer. METHODOLOGY: The study included patients with advanced pancreatic cancer who had failed gemcitabine-based chemotherapy. FOLFOX4 was administered biweekly as follows: oxaliplatin, 85 mg/m² as a 2-hour infusion (day 1); leucovorin, 200 mg/m²/day as a 2-hour infusion (days 1 and 2); 5-fluorouracil, bolus 400 mg/m²/day and 600 mg/m²/day as a 22-hour infusion (days 1 and 2). RESULTS: Forty-four patients received a total of 264 cycles of chemotherapy. There was 1 complete response (2.2%), 4 partial responses (9.1%), and 13 stable diseases (29.5%). The objective response rate was 11.4% and the tumor stabilization rate was 40.9%. The median time to progression was 9.9 weeks (95%CI: 8.2-11.5) and the median overall survival was 31.1 weeks (95%CI: 24.4-37.9). The common adverse events were hematologic toxicities: grade 3 or 4 neutropenia in 19 patients (43.2%), anemia in 9 patients (20.5%), and thrombocytopenia in 6 patients (13.5%). Grade 3 or 4 neuropathy occurred in 4 patients (9.1%). CONCLUSIONS: In gemcitabine-refractory pancreatic cancer, FOLFOX4 showed encouraging activity and was generally well-tolerated. However, careful attention needs to be paid to hematologic toxicities.

Clinical outcomes following secondary self-expandable metal stent (SEMS) insertion due to previous stent migration in malignant colorectal obstruction.

BACKGROUND: There has been no research on the clinical outcomes of secondary self-expandable metal stent (SEMS) placement after initial stent migration. Therefore, this study aimed to assess the clinical outcomes of secondary SEMS placement after initial stent migration compared to the outcomes of secondary SEMS placement done for reasons other than migration and identify factors predictive of long-term outcomes. METHODS: Between January 2005 and February 2011, a total of 422 patients underwent SEMS insertion for malignant colorectal obstruction at Severance Hospital. Of these, there were 98 cases of secondary SEMS placement, 38 of which were due to previous stent migration. We compared the clinical outcomes of secondary SEMS between stent migration and nonmigration groups. We also sought to identify risk factors for long-term outcomes of secondary SEMS after initial stent migration. RESULTS: The baseline clinical characteristics were similar between the two groups. The technical and clinical success rates of secondary SEMS insertion in the migration and nonmigration groups were 94.7% and 83.3% (p = 0.09) and 73.7% and 53.3% (p = 0.122), respectively. In the migration group, sustained clinical success after secondary SEMS was associated with the absence of complications after insertion of the first stent (p < 0.001) and a longer time interval (more than 100 days) between the first and second stent insertion (p = 0.011). CONCLUSIONS: Our data showed that secondary colorectal SEMS after stent migration is safe and effective. Moreover, the sustained clinical success of the secondary stent following migration was dependent on the outcomes of the first stent.

Endoscopic papillary large balloon dilatation alone is safe and effective for the treatment of difficult choledocholithiasis in cases of Billroth II gastrectomy: a single center experience.

BACKGROUND: Endoscopic treatment of difficult common bile duct (CBD) stones (diameter ≥ 10 mm, or four or more) is difficult in patients who have undergone Billroth II (B-II) gastrectomy. Endoscopic sphincterotomy (EST) can be particularly troublesome due to anatomical changes effected by the gastrectomy. AIM: We evaluated the efficacy and safety of endoscopic papillary large balloon dilation (EPLBD) with large-diameter dilation balloons in the treatment of difficult CBD stones in patients who have undergone B-II gastrectomy. MATERIALS AND METHODS: From June 2006 to April 2011, patients with difficult CBD stones and who had undergone B-II gastrectomy previously were included in this study. EPLBD was performed with a 10-18 mm balloon catheter. When selective cannulation through the sphincter was possible, EPLBD was performed without EST. EPLBD was otherwise performed after fistulotomy with needle knife. RESULTS: A total of 40 patients (32 male) underwent EPLBD for the retrieval of CBD stones, and concurrent fistulotomy was performed in seven patients. The median diameter of CBD was 13 mm (range 10-20 mm) and the balloon was 12 mm (range 10-17 mm). CBD stones were successfully removed in all patients. In only three patients, repeated sessions of ERCP were required for complete removal of CBD stones. Mechanical lithotripsy was required in only one case. Acute complications from EPLBD included mild pancreatitis in two patients (5.0 %). Severe complications, including perforation and bleeding, were not observed. Late complications included stone recurrence in one patient (2.5 %) and cholecystitis in four patients (10.0 %). CONCLUSIONS: In cases of B-II gastrectomy, EPLBD without EST is a safe and highly effective technique for the retrieval of difficult CBD stones. EPLBD should be considered as an alternative tool to conventional EST.

Clinical outcomes and predictive factors in oral corticosteroid-refractory active ulcerative colitis.

AIM: To evaluate the clinical outcomes and prognostic factors after intravenous corticosteroids following oral corticosteroid failure in active ulcerative colitis patients. METHODS: Consecutive patients with moderate to severe ulcerative colitis who had been treated with a course of intravenous corticosteroids after oral corticosteroid therapy failure between January 1996 and July 2010 were recruited at Severance Hospital, Seoul, South Korea. The disease activity was measured by the Mayo score, which consists of stool frequency, rectal bleeding, mucosal appearance at flexible sigmoidoscopy, and Physician Global Assessment. We retrospectively evaluated clinical outcomes at two weeks, one month, three months, and one year after the initiation of intravenous corticosteroid therapy. Two weeks outcomes were classified as responders or non-responders. One month, three month and one year outcomes were classified into prolonged response, steroid dependency, and refractoriness. RESULTS: Our study included a total of 67 eligible patients. At two weeks, 56 (83.6%) patients responded to intravenous corticosteroids. At one month, complete remission was documented in 18 (32.1%) patients and partial remission in 26 (46.4%). Eleven patients (19.7%) were refractory to the treatment. At three months and one year, we found 37 (67.3%) and 25 (46.3%) patients in prolonged response, ten (18.2%) and 23 (42.6%) patients in corticosteroid dependency, 8 (14.5%) and 6 (11.1%) patients with no response, respectively. Total 9 patients were underwent elective proctocolectomy within 1 year. The duration of oral corticosteroid therapy (> 14 d vs ≤ 14 d, P = 0.049) and lower hemoglobin level (≤ 11.0 mg/dL vs >11.0 mg/dL, P = 0.02) were found to be poor prognostic factors for response at two weeks. For one year outcome, univariate analysis revealed that only a partial Mayo score (≥ 6 vs <6, P = 0.057) was found to be associated with a poor response. CONCLUSION: The duration of oral corticosteroid therapy and lower hemoglobin level were strongly associated with poor outcome.

Correlations between endoscopic and clinical disease activity indices in intestinal Behcet's disease.

AIM: To develop a novel endoscopic severity model of intestinal Behcet's disease (BD) and to evaluate its feasibility by comparing it with the actual disease activity index for intestinal Behcet's disease (DAIBD). METHODS: We reviewed the medical records of 167 intestinal BD patients between March 1986 and April 2011. We also investigated the endoscopic parameters including ulcer locations, distribution, number, depth, shape, size and margin to identify independent factors associated with DAIBD. An endoscopic severity model was developed using significant colonoscopic variables identified by multivariate regression analysis and its correlation with the DAIBD was evaluated. To determine factors related to the discrepancy between endoscopic severity and clinical activity, clinical characteristics and laboratory markers of the patients were analyzed. RESULTS: A multivariate regression analysis revealed that the number of intestinal ulcers (≥ 2, P = 0.031) and volcanoshaped ulcers (P = 0.001) were predictive factors for the DAIBD. An endoscopic severity model (Y) was developed based on selected endoscopic variables as follows: Y = 47.44 + 9.04 × non-Ileocecal area + 11.85 × ≥ 2 of intestinal ulcers + 5.03 × shallow ulcers + 12.76 × deep ulcers + 4.47 × geographic-shaped ulcers + 26.93 × volcano-shaped ulcers + 8.65 × ≥ 20 mm of intestinal ulcers. However, endoscopic parameters used in the multivariate analysis explained only 18.9% of the DAIBD variance. Patients with severe DAIBD scores but with moderately predicted disease activity by the endoscopic severity model had more symptoms of irritable bowel syndrome (21.4% vs 4.9%, P = 0.026) and a lower rate of corticosteroid use (50.0% vs 75.6%, P = 0.016) than those with severe DAIBD scores and accurately predicted disease by the model. CONCLUSION: Our study showed that the number of intestinal ulcers and volcano-shaped ulcers were predictive factors for severe DAIBD scores. However, the correlation between endoscopic severity and DAIBD (r = 0.434) was weak.

Factors affecting colonoscope insertion time in patients with or without a colostomy after left-sided colorectal resection.

BACKGROUND/AIMS: We examined whether the insertion time for colonoscopies performed after left-sided resection was different in patients with a colostomy from that in patients without a colostomy and identified factors that could impact colonoscopy performance. METHODS: We included consecutive patients who underwent colonoscopy between July 2005 and March 2011 after left-sided colorectal resection for colorectal cancer. We classified surgical methods according to the presence or absence of a colostomy and evaluated colonoscope insertion time retrospectively. Furthermore, we analyzed factors that might affect insertion time. RESULTS: A total of 1,041 patients underwent colonoscopy after left-sided colorectal resection during the study period. The colonoscopy completion rate was 98.6 %, and the mean insertion time was 6.1 ± 4.6 min (median 4.7 min, range 0.3-35.8 min). A shorter resection length of colon, the presence of a colostomy, and a lower endoscopist case volume were found to be independent factors associated with prolonged insertion time in patients with left-sided colorectal resection. Among experienced colonoscopists, no colonoscopy-associated or clinical factors were found to affect insertion time. However, a shorter resection length of colon, the presence of a colostomy, and poor bowel preparation were associated with prolonged insertion time among inexperienced endoscopists. CONCLUSIONS: We identified three factors that affect colonoscope insertion time after left-sided colorectal resection, including the presence of a colostomy. Inexperienced endoscopists were much more affected by the presence of a colostomy after left-sided colorectal resection. These findings have implications for the practice and teaching of colonoscopy after left-sided colorectal resection.

Factors affecting insertion time for colonoscopy performed under intramuscular analgesia in patients with history of colorectal resection.

BACKGROUND: Colonoscopy can detect both early intraluminal recurrence and metachronous neoplasia after colorectal cancer resection. Because colon length and location change after colorectal resection, factors affecting insertion time during colonoscopy also might be altered. The goal of this study was to examine whether colonoscope insertion time differs between left-sided resection and right-sided resection and to identify factors that impact the performance of colonoscopy after colorectal resection. METHODS: We included consecutive patients who underwent colonoscopy between November 2005 and November 2009 after colorectal resection for colorectal cancer. We classified surgical methods into left-sided resection (left hemicolectomy, low anterior resection, anterior resection, Hartman, and Mile's operation) or right-sided resection (right hemicolectomy) and retrospectively evaluated the colonoscope insertion time. Moreover, we analyzed factors that might affect the insertion time. RESULTS: A total of 1,260 patients underwent colonoscopy after colorectal resection during the study period. Of these, 1,248 patients (771 men) who underwent complete colonoscopy were evaluated in this study. The colonoscopy completion rate was 99%, and the mean insertion time was 6.5±5.1 min (median, 5 min; range, 0.3-61 min). Right-sided resection, female gender, poor quality of bowel preparation, lower endoscopist case volume, open laparotomy, and colonoscopy performed more than 1 year after colorectal resection were found to be independent factors associated with prolonged insertion time. CONCLUSIONS: This large study identified six factors that affect colonoscope insertion time after colorectal resection. These findings have implications for the practice and teaching of colonoscopy after colorectal resection.

The usefulness of liver stiffness measurement using FibroScan in chronic hepatitis C in South Korea: a multicenter, prospective study.

AIM: We investigated the accuracy of liver stiffness measurement (LSM) in chronic hepatitis C (CHC) in a multicenter, prospective study in South Korea. METHODS: Between June 2005 and July 2009, 91 CHC patients without a previous history of antiviral treatment, clinical evidences of cirrhosis, coinfection with other viruses, and heavy alcohol consumption and with alanine aminotransferase (ALT) ≤5x upper limit of normal, total bilirubin ≤1.5 mg/dL, sufficient liver biopsy quality (≥15 mm and more than six portal tracts), interquartile range to median liver stiffness (LS) value ratio ≤0.21, and more than 10 valid measurements, were recruited. The Batts and Ludwig scoring system was used for histologic assessment. Age-platelet index (API), aspartate aminotransferase (AST)-to-platelet ratio index (APRI), and age-spleen-platelet ratio index (ASPRI) were calculated. Area under the receiver operating characteristic curve (AUROC) was used to evaluate the performance of LSM and other noninvasive models. RESULTS: The mean age was 47.9 years, and the mean LS value was 7.7 kPa (44 men and 47 women). LS value was highly correlated to the fibrosis stages (r=0.835, P<0.001). The AUROCs of LSM were 0.909 for ≥F2, 0.993 for ≥F3, and 0.970 for F=4 and were superior to those of API (0.72, 0.858, and 0.948, respectively), APRI (0.780, 0.887, and 0.904, respectively), and ASPRI (0.713, 0.862, and 0.957, respectively). The optimal cutoff LS values were 6.2 kPa for ≥F2, 7.7 kPa for ≥F3, and 11.0 kPa for F=4. CONCLUSIONS: Our data suggest that LSM can accurately assess liver fibrosis in patients with CHC and be applied in South Korea.

Risk Factors for Treatment Failure and Recurrence after Metronidazole Treatment for Clostridium difficile-associated Diarrhea.

BACKGROUND/AIMS: The incidence of treatment failure or recurrence of Clostridium difficile-associated diarrhea (CDAD) following metronidazole treatment has increased recently. We studied the treatment failure, recurrence rate, and risk factors predictive of treatment failure and recurrence after metronidazole treatment for CDAD. METHODS: We retrospectively identified consecutive patients who were admitted and treated for CDAD at a single tertiary institution in Korea over a recent 10-year period (i.e., 1998-2008). RESULTS: Metronidazole was administered as the initial treatment to 111 of 117 patients (94.9%) with CDAD. Fourteen patients (12.6%) had no clinical response to the metronidazole treatment, and in 13 patients (13.4%) CDAD recurred after successful metronidazole treatment. Diabetes mellitus (p=0.014) and sepsis (p=0.002) were independent risk factors for metronidazole treatment failure. Patients who had received surgery within 1 month before CDAD developed were more likely to experience a recurrence after metronidazole treatment (p=0.032). Vancomycin exhibited a higher response rate after treatment failure, and metronidazole showed a reasonable response rate in the treatment of recurrence. Treatment failure and recurrence rates increased with time after metronidazole treatment for CDAD over the 10-year study period. CONCLUSIONS: Our data suggest that diabetes mellitus and sepsis are independent risk factors for metronidazole treatment failure, and that operation history within 1 month of development of CDAD is a predictor of a recurrence after metronidazole treatment.