Narrow band imaging and serology in the assessment of premalignant gastric pathology.

BACKGROUND: Patient outcomes in gastric adenocarcinoma are poor due to late diagnosis. Detecting and treating at the premalignant stage has the potential to improve this. Helicobacter pylori is also a strong risk factor for this disease. AIMS: Primary aims were to assess the diagnostic accuracy of magnified narrow band imaging (NBI-Z) endoscopy and serology in detecting normal mucosa, H. pylori gastritis and gastric atrophy. Secondary aims were to compare the diagnostic accuracies of two classification systems using both NBI-Z and white light endoscopy with magnification (WLE-Z) and evaluate the inter-observer agreement. METHODS: Patients were prospectively recruited. Images of gastric mucosa were stored with histology and serum for IgG H. pylori and Pepsinogen (PG) I/II ELISAs. Blinded expert endoscopists agreed on mucosal pattern. Mucosal images and serological markers were compared with histology. Kappa statistics determined inter-observer variability for randomly allocated images among four experts and four non-experts. RESULTS: 116 patients were prospectively recruited. Diagnostic accuracy of NBI-Z for determining normal gastric mucosa was 0.87(95%CI 0.82-0.92), H. pylori gastritis 0.65(95%CI 0.55-0.75) and gastric atrophy 0.88(95%CI 0.81-0.94). NBI-Z was superior to serology at detecting gastric atrophy: NBI-Z gastric atrophy 0.88(95%CI 0.81-0.94) vs PGI/II ratio < 3 0.74(95%CI 0.62-0.85) p<.0001. Overall NBI-Z was superior to WLE-Z in detecting disease using two validated classifications. Inter-observer agreement was 0.63(95%CI 0.51-0.73). CONCLUSIONS: NBI-Z accurately detects changes in the GI mucosa which currently depend on histology. NBI-Z is useful in the detection of precancerous conditions, potentially improving patient outcomes with early intervention to prevent gastric cancer.

Systematic assessment with I-SCAN magnification endoscopy and acetic acid improves dysplasia detection in patients with Barrett's esophagus.

Background and study aims Enhanced endoscopic imaging with chromoendoscopy may improve dysplasia recognition in patients undergoing assessment of Barrett's esophagus (BE). This may reduce the need for random biopsies to detect more dysplasia. The aim of this study was to assess the effect of magnification endoscopy with I-SCAN (Pentax, Tokyo, Japan) and acetic acid (ACA) on dysplasia detection in BE using a novel mucosal and vascular classification system. Methods BE segments and suspicious lesions were recorded with high definition white-light and magnification endoscopy enhanced using all I-SCAN modes in combination. We created a novel mucosal and vascular classification system based on similar previously validated classifications for narrow-band imaging (NBI). A total of 27 videos were rated before and after ACA application. Following validation, a further 20 patients had their full endoscopies recorded and analyzed to model use of the system to detect dysplasia in a routine clinical scenario. Results The accuracy of the I-SCAN classification system for BE dysplasia improved with I-SCAN magnification from 69 % to 79 % post-ACA (P = 0.01). In the routine clinical scenario model in 20 new patients, accuracy of dysplasia detection increased from 76 % using a "pull-through" alone to 83 % when ACA and magnification endoscopy were combined (P = 0.047). Overall interobserver agreement between experts for dysplasia detection was substantial (0.69). Conclusions A new I-SCAN classification system for BE was validated against similar systems for NBI with similar outcomes. When used in combination with magnification and ACA, the classification detected BE dysplasia in clinical practice with good accuracy.Trials registered at ISRCTN (58235785).

Performance characteristics of unsedated ultrathin video endoscopy in the assessment of the upper GI tract: systematic review and meta-analysis.

BACKGROUND AND AIMS: Reports on the performance of unsedated ultrathin endoscopy via the transnasal (uTNE) and transoral (uTOE) routes are conflicting. We aimed to estimate the technical success rate, patient preference, and acceptability of uTNE and uTOE alone and in comparison with conventional EGD (cEGD; with or without sedation). METHODS: A systematic review and meta-analysis was performed on all primary studies reporting the outcomes of interest. Electronic databases (Cochrane library, MEDLINE, EMBASE) were searched on February 1, 2014. RESULTS: Thirty-four studies met the inclusion criteria with 6659 patients in total. The pooled technical success rate was 94.0% for uTNE (95% confidence interval [CI], 91.6-95.8; 30 studies) and 97.8% for uTOE (95% CI, 95.6-98.9; 16 studies). The difference in proportion of success for uTNE compared with cEGD was -2.0% (95% CI, -4.0 to -1.0; 18 studies), but that difference was not significant when uTNE < 5.9 mm in diameter was used (-1.0%; 95% CI, -3.0 to .0; 9 studies). There was no significant difference in success rate between uTOE and cEGD (.0%; 95% CI, -1.0 to 2.0; 10 studies). The pooled difference in proportion of patients who preferred uTNE over cEGD was 63.0% (95% CI, 49.0-76.0; 10 studies), whereas preference for uTOE versus cEGD was not significantly different (38.0%; 95% CI, -4.0 to 80.0; 2 studies). Acceptability was high for both uTNE (85.2%; 95% CI, 79.1-89.9; 16 studies) and uTOE (88.7%; 95% CI, 82.4-92.9; 10 studies). CONCLUSIONS: Technical success rate for uTNE < 5.9 mm is equivalent to cEGD. uTNE has high patient acceptability, with better patient preference, and therefore could be a useful alternative to cEGD for screening purposes. uTOE had a similar technical success rate but an equivocal preference to cEGD.