Optical enhancement imaging versus acetic acid for detecting gastric intestinal metaplasia: A randomized,comparative trial

Background and aimsThe diagnosis of gastric intestinal metaplasia (GIM) is still challenging. Optical Enhancement technology (OE) may improve the detection of GIM. We compared detection of GIM with OE, acetic acid and the Sydney biopsy protocol in a surveillance population.MethodsConsecutive patients with atrophic gastritis or known GIM were prospectively included. The stomach was examined with high definition whitelight endoscopy, followed by OE or acetic acid with targeted biopsies (1:1 randomisation). Subsequently, five random biopsies were taken according to the updated Sydney system.ResultsA total of 154 patients were randomized. Higher proportions of patients with GIM were detected by OE and acetic acid versus random biopsy (60.5% vs 35.5%, 67.1% vs 31.5%, respectively; P < 0.0001 for both comparisons). The combined use of targeted biopsies and random biopsies provides high diagnostic yields for GIM (78.9% in OE group and 83.6% in acetic acid group). In addition, the proportion of extensive GIM was significantly increased when image enhanced endoscopy was used instead of white light endoscopy (P = 0.029, P = 0.048, respectively).ConclusionsOE and acetic acid showed comparable results diagnosing GIM in the study. Targeted biopsies plus random biopsies should be used complementary in high risk populations.     

Narrow-band imaging optical chromocolonoscopy： Advantages and limitations

Narrow-band imaging （NBI） is an innovative optical technology that modifies the center wavelength and bandwidth of an endoscope＇s light into narrow-band illumination of 415 ：1： 30 nm. NBI markedly improves capillary pattern contrast and is an in vivo method for visualizing microvessel morphological changes in superficial neoplastic lesions. The scientific basis for NBI is that short wavelength light falls within the hemoglobin absorption band, thereby facilitating clearer visualization of vascular structures. Several studies have reported advantages and limitations of NBI colonoscopy in the colorectum. One difficulty in evaluating results, however, has been nonstandardization of NBI systems （Sequential and nonsequential）. Utilization of NBI technology has been increasing worldwide, but accurate pit pattern analysis and sufficient skill in magnifying colonoscopy are basic fundamentals required for proficiency in NBI diagnosis of colorectal lesions. Modern optical technology without proper image interpretation wastes resources, confuses untrained endoscopists and delays interinstitutional validation studies. Training in the principles of ＂optical image-enhanced endoscopy＂ is needed to close the gap between technological advancements and their clinical usefulness. Currently available evidence indicates that NBI constitutes an effective and reliable alternative to chromocolonoscopy for in vivo visualization of vascular structures, but further study assessing reproducibility and effectiveness in the colorectum is ongoing at various medical centers.     

The diagnostic accuracy of chromoendoscopy for dysplasia in ulcerative colitis: meta‐analysis of six randomized controlled trials

Aim The diagnostic accuracy of chromoendoscopy for dysplasia in ulcerative colitis (UC) was systematically evaluated. Method Original studies in any language were searched from PubMed and Embase. Meta‐analysis of prospective studies that compared chromoendoscopy with histological diagnosis was carried out. Sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated for each study and pooled together; summary receiver operating characteristic (ROC) and subgroup analyses were performed, while the quality of the study and heterogeneity were assessed. Results Six randomized controlled trials were included, which used methylene blue or indigo carmine dye spray. The meta‐analysis demonstrated a pooled sensitivity of 83.3% (95% confidence interval (CI), 35.9–99.6%), specificity of 91.3% (95% CI, 43.8–100%), and DOR of 17.544 (95% CI, 1.245–247.14). Subgroup analyses revealed that both the methylene blue dye spray subgroup and the unspecified endoscopist subgroup include the same studies, and their pooled sensitivity and specificity were 0.737 and 0.917, respectively. The other subgroup, which used indigo carmine dye spray, had overall higher sensitivity (0.930) and lower specificity (0.910). Conclusion Chromoendoscopy has medium to high sensitivity and a high diagnostic accuracy for dysplastic lesions in UC.     

胃镜下黏膜染色对萎缩性胃炎及其癌前病变的诊断价值

目的:探讨内镜喷洒亚甲蓝对萎缩性胃炎并肠上皮化生以及不典型增生的诊断价值.方法:126例胃镜诊断为萎缩性胃炎的病例常规活检后予0.5%亚甲蓝作黏膜染色,对异常染色区追加活检,对比分析染色前后病理组织学检查结果.结果:①普通胃镜直视下诊断与病理诊断符合率为60.3%,染色胃镜直视下诊断与病理诊断符合率为75.4%;②染色后萎缩性胃炎伴肠上皮化生检出率77.8%,不典型增生检出率38.1%,均较染色前有所提高(P＜0.01).结论:染色胃镜对萎缩性胃炎及其癌前病变的诊断价值优于普通胃镜.     

胃良,恶性病变的煌蓝色素内镜鉴别诊断

本文报告了用煌蓝对胃粘膜染色的结果。用煌蓝染色后,可以非常清楚地观察到正常粘膜的胃小区结构,小区沟线呈淡蓝色,胃小区呈规则的网状结构。肠上皮化生灶表现了明显的蓝色,胃粘膜的良性隆起型病变,如息肉表现了淡蓝色,良性溃疡的底部显示蓝色,溃疡边缘显示了正常的小区结构。而粘膜恶性病变表现了界限清楚的鲜红色或粉红色。因此,早期胃癌非常容易被查出,特别是普通胃镜检查时遗漏的Ⅱb型癌。由于良、恶性病变显示了明显不同的色彩,证明这种方法在胃癌和胃良性病变的鉴别诊断中非常有用。     

The usefulness of chromoendoscopy with methylene blue in Barrett’s metaplasia and early esophageal carcinoma

Background Barrett’s esophagus is a condition that is premalignant for adenocarcinoma of the esophagus and the esophagogastric junction. Early detection of Barrett’s metaplasia and dysplasia is very important to decrease the mortality and morbidity from esophageal adenocarcinoma cancer. This study aimed to evaluate the effectiveness of methylene blue–targeted biopsies in the differential diagnosis of intestinal metaplasia, dysplasia, and superficial esophageal carcinoma. Methods A total of 109 patients (43 women and 66 men; average age, 62.32 ± 10.61 years; range, 33–82 years) were enrolled for the study. Four groups were designed before endoscopic examinations. The patients for these groups were selected at the conventional endoscopy, and then chromoendoscopy was performed. The esophagus was stained with methylene blue, after which six biopsies were taken from stained and unstained areas. Results Conventional and chromoendoscopic assessments were compared with histopathologic examination. The sensitivity of chromoendoscopy for Barrett’s epithelium was superior to that of conventional endoscopy (p < 0.05). However, there was no statistical difference between the two methods in the diagnosis of esophagitis or esophageal carcinoma (p > 0.05). Stained biopsies were superior to unstained biopsies in terms of sensitivity for Barrett’s epithelium and esophageal carcinoma (p < 0.001). Conclusion Chromoendoscopy is useful for delineating Barrett’s epithelium and for indicating the correct location for securing biopsies where dysplasia or early esophageal cancer is suspected.     

Toward an easier indigocarmine chromoendoscopy

Indigocarmine chromoendoscopy has been proven to improve the detection of colonic lesions during screening colonoscopy, and is associated with increased adenoma detection rates. Furthermore, it is commonly used to help in the delineation and characterization of colorectal neoplasms. However, it usually requires the use of a spraying catheter that decreases the suction capacity of the endoscope, and is time- consuming. Herein, we report on the feasibility of indigo carmine chromoendoscopy during colonoscopy without using a spraying catheter, with the dye being administered through the air/water channel of the endoscope. Since the suction channel remains free, the air can be exsufflated and the staining then applies uniformly onto the colonic walls with the excess indigocarmine dye being immediately eliminated. In our experience with various types of colonoscopes and cap-assisted colonoscopy, this procedure makes indigocarmine chromoendoscopy much easier and quicker to perform, and might save the use of a spray catheter.