Digital Chromoendoscopy With i-Scan for In Vivo Prediction of Advanced Colorectal Neoplasia: A Multicenter Study.

BACKGROUND: Recent studies have analyzed the potential of advanced endoscopic imaging techniques for differentiating hyperplastic and adenomatous colorectal lesions. Latest endoscopic resection techniques now also allow for treatment of more advanced staged lesions including treatment of early cancerous lesions. AIMS: To assess the potential of the i-scan technology to differentiate between adenomatous polyps and advanced staged neoplasia. METHODS: Consecutive patients undergoing colonoscopy at a tertiary referral center were included. After a dedicated training, participating endoscopists underwent a review of 298 unknown images of colonic lesions to assess colorectal lesion histology. RESULTS: Overall accuracy for prediction of advanced staged neoplasia was 92.2% (sensitivity: 94.2%, specificity 90.9%). The positive and negative predictive values were calculated as 87.5% and 95.9%, respectively. The κ-value for differentiating adenomatous polyps and advanced staged neoplasia was 0.8193 (0.7894 to 0.8492). Intraobserver agreement was calculated with a κ-value of 0.9301 (0.8875 to 0.9727). CONCLUSIONS: Accurate interpretation of i-scan images for prediction of advanced colorectal neoplasia can successfully be performed even by nonexpert endoscopists with a high overall accuracy and excellent interobserver agreements.

The place of new oral anticoagulants in travel medicine.

New oral anticoagulants are increasingly used instead of vitamin K antagonists or low molecular weight heparins. Hence, more individuals treated with new oral anticoagulants will seek travel medicine advice. Travel medicine experts should therefore become familiar with new oral anticoagulants and with their impact and role in travel medicine. This review summarizes pharmacological characteristics and approved indications of dabigatran, rivaroxaban and apixaban, and highlights their relevance for travellers on permanent oral anticoagulation and for the prophylaxis of travellers' thrombosis. Compared to vitamin K antagonists, the new oral anticoagulants have many advantages: they do not have interactions with food, they have lower potential for drug-drug interactions and do not require regularly performed laboratory tests. The oral administration, obviating the need to carry needles and syringes during travel may give the new oral anticoagulants a further advantage over low molecular weight heparins. Clinical experience with the new oral anticoagulants, however, is still rather limited and there is concern regarding the clinical management of patients treated with new oral anticoagulants who suffer from severe bleeding or who need urgent invasive procedures. Overall, it remains an individual decision based on a risk/benefit analysis as to whether or not patients on long-term treatment with vitamin K antagonists should be switched to new oral anticoagulants for intended travel. Further caution is also indicated so that the availability of orally administered new anticoagulants should not lead to undifferentiated and unjustified prescription of anticoagulants for the prophylaxis of traveller's thrombosis.

Confocal laser endomicroscopy for in vivo diagnosis of Clostridium difficile associated colitis - a pilot study.

BACKGROUND: Clostridium difficile infection (CDI) is one of the most dreaded causes of hospital-acquired diarrhea. Main objective was to investigate whether confocal laser endomicroscopy (CLE) has the capability for in vivo diagnosis of C. difficile associated histological changes. Second objective was to prove the presence of intramucosal bacteria using CLE. METHODS: 80 patients were prospectively included, 10 patients were diagnosed with CDI based on toxigenic culture. To validate the presence of intramucosal bacteria ex vivo, CLE was performed in pure C. difficile culture; additionally fluorescence in situ hybridization (FISH) was performed. Finally, CLE with fluorescence labelled oligonucleotide probe specific for C. difficile was performed ex vivo in order to prove the presence of bacteria. RESULTS: CLE identified CDI-associated histological changes in vivo (sensitivity and accuracy of 88.9% and 96.3%). In addition, intramucosal bacteria were visualized. The presence of these bacteria could be proven by CLE with labeled, specific molecular C. difficile probe and FISH-technique. Based on comparison between CLE and FISH analyses, sensitivity and specificity for the presence of intramucosal bacteria were 100%. CONCLUSION: CLE has the potential for in vivo diagnosis of CDI associated colitis. In addition, CLE allowed the detection of intramucosal bacteria in vivo.

Virtual chromoendoscopy for prediction of severity and disease extent in patients with inflammatory bowel disease: a randomized controlled study.

BACKGROUND: Increased vascular permeability and angiogenesis play a crucial role in the pathogenesis of inflammatory bowel disease (IBD). Aim was to determine whether computed virtual chromoendoscopy has the potential to enhance assessment of disease severity and extent in patients with mild or inactive IBD in comparison to high-definition white-light endoscopy. METHODS: Consecutive patients with IBD were randomly assigned at a 1:1 ratio to undergo colonoscopy with high-definition white light (group A) or computed virtual chromoendoscopy (group B). The mucosal vascular pattern and any mucosal abnormalities were recorded. Subsequent to endoscopic characterization targeted, biopsies were obtained from every segment for subsequent histopathological analysis of disease activity. RESULTS: Overall, 100 patients were screened to participate in this study of whom 78 patients (high-definition white light, n = 39; computed virtual chromoendoscopy, n = 39) completed the study protocol thereby matching the previously calculated sample size. Average duration of the examination was 18 minutes in group A and 20.5 minutes in group B that was not statistically significant. When comparing the endoscopic prediction of inflammatory extent and activity with the histological results, an overall agreement of 48.71% and 53.85% (group A) and 92.31% and 89.74% (group B) was found, respectively. These differences were statistically significant (P = 0.0009 and P = 0.066). CONCLUSIONS: This study indicates that computed virtual chromoendoscopy significantly improves the diagnosis of the severity and extent of mucosal inflammation in patients with IBD. This newly developed imaging technique may therefore have important implications for therapeutic interventions in patients with IBD.

Assessment of Crohn's disease activity by confocal laser endomicroscopy.

BACKGROUND: Confocal laser endomicroscopy (CLE) allows microscopic imaging within the mucosal layer of the gut during ongoing endoscopy. Different studies have addressed the potential of CLE for in vivo diagnosis of ulcerative colitis and microscopic colitis. However, there are no data on the utility of CLE for in vivo diagnosis of Crohn's disease (CD). The aim was to assess the clinical utility of CLE in patients with CD and to determine whether disease activity can be graded using CLE. METHODS: Consecutive patients with and without CD were enrolled. The colonic mucosa was examined by standard white-light endoscopy followed by CLE. The features seen on CLE were compared between CD patients and controls. RESULTS: In all, 76 patients with CD were screened, of whom 54 patients were included in the present study. Eighteen patients without inflammatory bowel disease (IBD) served as controls. A significantly higher proportion of patients with active CD had increased colonic crypt tortuosity, enlarged crypt lumen, microerosions, augmented vascularization, and increased cellular infiltrates within the lamina propria. In quiescent CD, a significant increase in crypt and goblet cell number was detected compared with controls. Based on our findings, we propose a Crohn's Disease Endomicroscopic Activity Score (CDEAS) for assessing CD activity in vivo. CONCLUSIONS: CLE has the potential to significantly improve diagnosis of CD compared with standard endoscopy. These findings should be evaluated in future prospective trials to assess the value of this newly developed CLE score for prediction of disease course and therapeutic responses.