Comparison of high-resolution magnification narrow-band imaging and white-light endoscopy in the prediction of histology in Barrett's oesophagus.

OBJECTIVE: To evaluate whether there is any appreciable difference in imaging characteristics between high-resolution magnification white-light endoscopy (WLE-Z) and narrow-band imaging (NBI-Z) in Barrett's oesophagus (BE) and if this translates into superior prediction of histology. MATERIAL AND METHODS: This was a prospective single-centre study involving 21 patients (75 areas, corresponding NBI-Z and WLE-Z images) with BE. Mucosal patterns (pit pattern and microvascular morphology) were evaluated for their image quality on a visual analogue scale (VAS) of 1-10 by five expert endoscopists. The endoscopists then predicted mucosal morphology based on four subtypes which can be visualized in BE. Type A: round pits, regular microvasculature; type B: villous/ridge pits, regular microvasculature; type C: absent pits, regular microvasculature; type D: distorted pits, irregular microvasculature. The sensitivity (Sn), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV) and accuracy (Acc) were then compared with the final histopathological analysis and the interobserver variability calculated. RESULTS: The overall pit and microvasculature quality was significantly higher for NBI-Z, pit: NBI-Z=6, WLE-Z=4.5, p < 0.001; microvasculature: NBI-Z=7.3, WLE-Z=4.9, p < 0.001. This translated into a superior prediction of histology (Sn: NBI-Z: 88.9, WLE-Z: 71.9, p < 0.001). For the prediction of dysplasia, NBI-Z was superior to WLE-Z (chi(2)=10.3, p < 0.05). The overall kappa agreement among the five endoscopists for NBI-Z and WLE-Z, respectively, was 0.59 and 0.31 (p < 0.001). CONCLUSIONS: NBI-Z is superior to WLE-Z in the prediction of histology in BE, with good reproducibility. This novel imaging modality could be an important tool for surveillance of patients with BE.

Nonsteroidal antiinflammatory drugs and the small intestine.

PURPOSE OF REVIEW: The small intestine may be a more common site for nonsteroidal antiinflammatory drug toxicity than the gastroduodenal mucosa. Two-thirds of regular nonsteroidal antiinflammatory drug users develop subclinical small bowel enteropathy. This review highlights this emerging issue in patients requiring antiinflammatory drugs. RECENT FINDINGS: Nonsteroidal antiinflammatory drug enteropathy is a stepwise process involving direct mucosal toxicity, mitochondrial damage, breakdown of intercellular integrity, enterohepatic recirculation and neutrophil activation by luminal contents including bacteria. Unlike upper gastrointestinal toxicity, cyclooxygenase-mediated mechanisms are probably less important. Newer imaging modalities such as capsule endoscopy studies demonstrate nonsteroidal antiinflammatory drug-induced small bowel erosions, but the clinical implications are unclear. SUMMARY: Nonsteroidal antiinflammatory drug toxicity to the small intestine is common. Useful research tools have been developed to indirectly measure intestinal inflammation and permeability, but these are not generally available to the clinician, although enteroscopy and capsule endoscopy can be illuminating. Anaemia or hypoalbuminaemia are useful indications of nonsteroidal antiinflammatory drug enteropathy. Cessation of the drug would be the preferred option, alternatively there are experimental data to support the use of sulphasalazine and metronidazole. Animal models are unravelling new mechanisms for mucosal toxicity beyond the cyclooxygenase model, including mucosal oxidative injury and nitric oxide mediated pathways.

Cyclooxygenase-2 inhibitors.

PURPOSE OF REVIEW: The purpose of this review is to summarize new information regarding the use of selective inhibitors of the cyclooxygenase-2 enzyme, emphasizing recent developments regarding cardiovascular risk. RECENT FINDINGS: Selective cyclooxygenase-2 inhibitors are as effective as nonselective nonsteroidal antiinflammatory drugs in relieving pain and inflammation but are associated with significantly fewer gastric, duodenal, and intestinal ulcers and ulcer complications. Cyclooxygenase-2 inhibitors may also reduce colorectal polyp development or recurrence as well as reduce the risk of colorectal and esophageal cancer. Some, but not all, studies have suggested increased myocardial infarction with certain cyclooxygenase-2 inhibitors, in particular rofecoxib. It is unclear whether this is a class effect because there are inconclusive data to incriminate celecoxib despite a relatively large number of clinical trials enrolling a large number of patients. Rofecoxib was voluntarily withdrawn by the manufacturer. The European Medicines Agency concluded that cyclooxygenase-2 inhibitors are contraindicated in patients with established cardiovascular disease, should be used with caution in patients with risk factors, and were justified in patients at risk for serious gastrointestinal adverse events. SUMMARY: Rofecoxib, but perhaps not all cyclooxygenase-2 inhibitors, may be associated with increased risk for myocardial infarction. It is unclear whether nonselective nonsteroidal antiinflammatory drugs increase or decrease the rate of myocardial infarction. The final truth awaits further studies.