Autofluorescence imaging and narrow-band imaging for the detection of early neoplasia in patients with Barrett's esophagus

High-resolution endoscopy (HRE), magnifying endoscopy, auto-fluorescence endoscopy, and narrow-band imaging (NBI) are promising techniques that could improve the detection of early neoplasia and the efficacy of endoscopic surveillance in patients with Barrett's esophagus. HRE improves the detection of lesions by white light, and video autofluorescence imaging (AFI) may have additional value in terms of sensitivity. The strengths ofAFI are its high sensitivity and a high negative predictive value,while potential limitations are its moderate specificity and positive predictive value. NBI enhances the mucosal and vascular patterns (i. e. the mucosal morphology) without the need for chromoendoscopy. The mucosal morphology features may be used to distinguish early neoplasia from nondysplastic Barrett's esophagus. Magnification is required for optimal use of NBI,which is a limitation of this technique. NBI with magnifying endoscopy could, however, be used for targeted inspection of lesions detected first by HRE or AFI. This approach has been shown to reduce the false-positive rate associated with AFI while maintaining its high sensitivity. To date, AFI and NBI have been used separately in two different prototypes, but a prototype endoscope that incorporates all of these techniques has recently become available. It is expected that future refinement of the autofluorescence and narrow-band modules may further increase their diagnostic value and ultimately improve the effectiveness of surveillance of Barrett's esophagus.     

Autofluorescence endoscopy in surveillance of Barrett's esophagus: a multicenter randomized trial on diagnostic efficacy

BACKGROUND AND STUDY AIMS: The reference surveillance method in patients with Barrett's esophagus is careful endoscopic observation, with targeted as well as random four-quadrant biopsies. Autofluorescence endoscopy (AFE) may make it easier to locate neoplasia. The aim of this study was to elucidate the diagnostic accuracy of surveillance with AFE-guided plus four-quadrant biopsies in comparison with the conventional approach. PATIENTS AND METHODS: A total of 187 of 200 consecutive Barrett's esophagus patients who were initially enrolled (73 % male, mean age 67 years, mean Barrett's segment length 4.6 cm), who underwent endoscopy for Barrett's esophagus in four study centers, were randomly assigned to undergo either AFE-targeted biopsy followed by four-quadrant biopsies or conventional endoscopic surveillance, also including four-quadrant biopsies (study phase 1). After exclusion of patients with early cancer or high-grade dysplasia, who underwent endoscopic or surgical treatment, as well as those who declined to participate in phase 2 of the study, 130 patients remained. These patients were examined again with the alternative method after a mean of 10 weeks, using the same methods described. The main study parameter was the detection of early cancer/adenocarcinoma or high-grade dysplasia (HGD), comparing both approaches in study phase 1; the secondary study aim in phase 2 was to assess the additional value of the AFE-guided approach after conventional surveillance, and vice versa. Test accuracy measures were derived from study phase 1. RESULTS: In study phase 1, the AFE and conventional approaches yielded adenocarcinoma/HGD rates of 12 % and 5.3 %, respectively, on a per-patient basis. With AFE, four previously unrecognized adenocarcinoma/HGD lesions were identified (4.3 % of the patients); with the conventional approach, one new lesion (1.1 %) was identified. Of the 19 adenocarcinoma/HGD lesions detected during AFE endoscopy in study phase 1, eight were visualized, while 11 were only detected using untargeted four-quadrant biopsies (sensitivity 42 %). Of the 766 biopsies classified at histology as being nonneoplastic, 58 appeared suspicious (specificity 92 %, positive predictive value 12 %, negative predictive value 98.5 %). In study phase 2, AFE detected two further lesions in addition to the initial alternative approach in 3.2 % of cases, in comparison with one lesion with conventional endoscopy (1.7 %). CONCLUSIONS: In this referral Barrett's esophagus population with a higher prevalence of neoplastic lesions, the AFE-guided approach improved the diagnostic yield for neoplasia in comparison with the conventional approach using four-quadrant biopsies. However, AFE alone was not suitable for replacing the standard four-quadrant biopsy protocol.     

Non-biopsy detection of intestinal metaplasia and dysplasia in Barrett's esophagus: a prospective multicenter study

BACKGROUND AND STUDY AIMS: There have been no multicenter studies investigating the use of magnification chromoendoscopy (MCE) for the detection of intestinal metaplasia and dysplasia/cancer in Barrett's esophagus. Our aims were to assess the ability of MCE to predict the histological diagnosis (non-biopsy detection), to compare the yield of MCE-targeted versus random biopsies for dysplasia, and to compare procedure times. PATIENTS AND METHODS: In this prospective multicenter study, patients with known or suspected Barrett's esophagus underwent MCE with indigo carmine dye staining. Three mucosal patterns (ridge/villous, circular, and irregular/distorted) were standardized, based on past experience. Mucosal patterns were noted and target biopsies were obtained only if irregular/distorted patterns were identified. Otherwise, random four-quadrant biopsies were obtained. RESULTS: A total of 56 patients (mean age 64 years, mean length of Barrett's esophagus 2.7cm) were prospectively evaluated: 38 patients (67.8 %) had ridge/villous patterns, four patients (7.1 %) had circular patterns, four patients (7.1 %) had irregular/distorted patterns, and ten patients (17.8 %) had a combination of patterns. Histologically, intestinal metaplasia was not shown in eight patients (14.2 %), nondysplastic Barrett's esophagus was diagnosed in 30 patients (53.5 %), low-grade dysplasia was detected in 12 patients (21.4 %), and high-grade dysplasia was detected in six patients (10.7 %). An irregular/distorted pattern either throughout the entire segment of Barrett's esophagus or in combination with a ridge/villous or circular pattern had a sensitivity or 83 %, a specificity of 88 %, a positive predictive value of 45 %, and a negative predictive value of 98 % for high-grade dysplasia. The yield of high-grade dysplasia was similar for the two techniques but the time taken to perform MCE was less than the time taken to perform random biopsies. CONCLUSION: An irregular/distorted pattern is specific for high-grade dysplasia and so it may not be necessary to perform biopsies in patients with ridge/villous or circular mucosal patterns.     

Narrow-band imaging in the diagnosis of colorectal mucosal lesions: a pilot study

BACKGROUND AND STUDY AIMS: A newly developed narrow-band imaging (NBI) technique, in which modified optical filters were used in the light source of a video endoscope system, was applied during colonoscopy in a clinical setting. This pilot study evaluated the clinical feasibility of the NBI system for evaluating colorectal lesions. PATIENTS AND METHODS: A total of 43 colorectal lesions in 34 patients were included in the study. The quality of visualization of colorectal lesions and the accuracy of differentiation between neoplastic and non-neoplastic lesions using the NBI system were evaluated in comparison with results from conventional colonoscopy and with chromoendoscopy. RESULTS: For pit pattern delineation, NBI was superior to conventional endoscopy (P < 0.001), but inferior to chromoendoscopy (P < 0.05). NBI achieved better visualization of the mucosal vascular network and of the hue of lesions than conventional endoscopy (P < 0.05). However there was no significant difference between NBI and chromoendoscopy in differentiating neoplastic from non-neoplastic lesions (both techniques had a sensitivity of 100 % and a specificity 75 %). This was better than the results of conventional colonoscopy (sensitivity 83 %, specificity 44 %; P < 0.05 for specificity). CONCLUSIONS: These results suggest that in the examination of colonic lesions the NBI system provides imaging features additional to those of both conventional endoscopy and chromoendoscopy. For distinguishing neoplasms from non-neoplastic lesions, NBI was equivalent to chromoendoscopy.     

Diagnosis of esophagogastric tumors

With regard to esophageal tumors, important reports on several topics have been published recently. 1) The place of endoscopic ultrasonography (EUS) as the best locoregional staging technique for cancer of the esophagus has been further consolidated. The addition of fine-needle aspiration makes EUS more sensitive than computed tomography (CT) and more accurate than CT or EUS alone for nodal staging. 2) High-resolution endoscopy with chromoendoscopy has been found to be very effective for mucosal lesions, but not for submucosal lesions. In combination with EUS, the sensitivity for submucosal tumors increases up to 60 %. 3) Autofluorescence-guided biopsy has been reported to be a good tool for detecting high-grade dysplasia. A narrow-band imaging system improved the overall accuracy for depth of invasion. 4) The incidence of hypopharyngeal cancer increases after resection for esophageal carcinoma. Patients with a scattered staining pattern after application of Lugol's solution are more prone to develop upper lesions. 5) Fluorescence imaging makes it possible to detect low-grade intraepithelial neoplasia in Barrett's mucosa, with fewer biopsies. 6) Patients with Barrett's esophagus with a length of over 3 cm had a significantly greater prevalence of dysplasia in comparison with those in the whom the Barrett's segment was shorter than 3 cm (23 % vs. 9 %, P = 0.0001). With regard to gastric tumors, 1) Helicobacter pylori eradication can significantly reduce the development of gastric cancer, but only in patients without precancerous lesions. 2) Intestinal metaplasia types II and III have been shown to have a higher rate of progression to low-grade dysplasia than type I. 3) With regard to screening in asymptomatic individuals, serum pepsinogen may represent an alternative to conventional fluoroscopy methods. 4) In patients who have undergone esophagectomy for esophageal cancer, annual follow-up endoscopies are vital for detecting early secondary gastric cancer and ulcerations in which curative treatment is possible. 5) High-resolution endoscopy allows more precise diagnosis of early gastric cancer. The presence of irregular minute vessels and variations in vessel caliber were found to be specific of early gastric cancer. The small regular pattern of sulci and ridges was observed significantly more frequently in differentiated carcinoma than in undifferentiated carcinoma. 6) Infrared-ray electronic endoscopy combined with indocyanine green injection appears to be effective in detecting sentinel nodes that contain metastases in patients with gastric cancer. 7) Gastric adenocarcinoma was found to show specific changes in the fluorescence spectra emitted, in comparison with normal gastric mucosa. However, there was wide variation in the emitted autofluorescence spectra in gastric cancer with signet-ring cells in comparison with normal mucosa.     

Detection of Barrett's epithelium by acoustic microscopy

Barrett's esophagus is associated with increased risk of adenocarcinoma of the gastroesophageal junctional region. The presence of goblet cells (intestinal metaplasia) in columnar cell-lined esophageal mucosa defines Barrett's change. The diagnosis of Barrett's esophagus is based on the presence of intestinal metaplasia in a biopsy from an endoscopically visualized abnormal columnar epithelium. In this pilot study, acoustic microscopy was used to identify the mucosal structure of 10 distal esophageal biopsies. Sections cut at 5 microm of archival paraffin blocks on glass slides were used for this study. Acoustic microscopy permitted the identification of low- and high-power images of epithelial architecture and cellular detail, including Barrett's epithelium. This modality of visualization has the potential to detect lesions such as Barrett's metaplasia, low- and high-grade dysplasia and early carcinoma. If it can be applied to in vivo endoscopy, acoustic microscopy has the potential to increase the accuracy of the diagnosis of Barrett's esophagus, dysplasia and malignancy by providing a method of accurately directing biopsies at endoscopy.     

A randomized, prospective cross-over trial comparing methylene blue-directed biopsy and conventional random biopsy for detecting intestinal metaplasia and dysplasia in Barrett's esophagus

BACKGROUND AND STUDY AIMS: The value of methylene blue-directed biopsies (MBDB) in detecting specialized intestinal metaplasia and dysplasia in Barrett's esophagus remains unclear. The aim of this study was to compare the accuracy of MBDB with random biopsy in detecting intestinal metaplasia and dysplasia in patients with Barrett's esophagus. PATIENTS AND METHODS: A prospective, randomized, cross-over trial was undertaken to compare MBDB with random biopsy in patients with Barrett's esophagus segments 3 cm or more in length without macroscopic evidence of dysplasia or cancer. Dysplasia was graded as: indefinite for dysplasia, low-grade dysplasia, high-grade dysplasia, or carcinoma, and was reported in a blinded fashion. RESULTS: Fifty-seven patients were recruited, 44 of whom were male. A total of 1,269 biopsies were taken (MBDB-651, random biopsie-618). Analysis of the results by per-biopsy protocol showed that the MBDB technique diagnosed significantly more specialized intestinal metaplasia (75 %) compared to the random biopsy technique (68 %; P = 0.032). The sensitivity and specificity rates of MBDB for diagnosing specialized intestinal metaplasia were 91 % (95 % CI, 88 - 93 %) and 43 % (95 % CI, 36 - 51 %), respectively. The sensitivity and specificity rates of MBDB for diagnosing dysplasia or carcinoma were 49 % (95 % CI, 38 - 61 %) and 85 % (95 % CI, 82 - 88 %), respectively. There were no significant differences in the diagnosis of dysplasia and carcinoma - MBDB 12 %, random biopsy 10 %. The methylene blue staining pattern appeared to have an influence on the detection of specialized intestinal metaplasia and dysplasia/carcinoma. Dark blue staining was associated with increased detection of specialized intestinal metaplasia (P < 0.0001), and heterogeneous staining (P = 0.137) or no staining (P = 0.005) were associated with dysplasia and/or carcinoma detection. The MBDB technique prolonged the endoscopy examination by an average of 6 min. CONCLUSION: The diagnostic accuracy of the MBDB technique was superior to that of the random biopsy technique for identifying specialized intestinal metaplasia, but not dysplasia or carcinoma. The intensity of methylene blue staining has an influence on the detection of specialized intestinal metaplasia and dysplasia or carcinoma, which may help in targeting the biopsies. Although MBDB prolongs the endoscopy procedure slightly, it is a safe and well-tolerated procedure. Further clinical studies on the MBDB technique exclusively in endoscopically normal dysplastic Barrett's esophagus are needed.     

Methylene blue chromoendoscopy for the detection of Barrett's esophagus in a Greek cohort

BACKGROUND AND STUDY AIMS: Specialized columnar epithelium of Barrett's esophagus is a precursor of dysplasia and adenocarcinoma, and methylene blue selectively stains this type of epithelium. The present prospective study examined the detection of short-segment and long-segment Barrett's esophagus using methylene blue chromoendoscopy-directed biopsies, in comparison with biopsies directed using conventional endoscopic criteria. PATIENTS AND METHODS: Biopsies were obtained from macroscopically conspicous areas in the distal esophagus observed during conventional endoscopy in a total of 975 patients. Immediately after conventional biopsies, the distal esophagus was sprayed with methylene blue and directed biopsies were then obtained from the stained regions. All patients with a histologically established Barrett's esophagus underwent a second upper gastrointestinal endoscopy within 1 year in order to assess the reproducibility of the method. RESULTS: In a total of 3,900 conventional biopsy specimens (without staining), 54 specimens (1.4%) were found to show Barrett's esophagus and were confined to 16 of the 975 patients (1.6%). Of the total 130 directed biopsy specimens obtained during chromoendoscopy, 114 (87.7%) revealed Barrett's esophagus (P<0.00001) and were confined to 35 of the 975 patients (3.5%; P < or = 0.001). The findings were confirmed within 1 year in all dye-positive patients. CONCLUSIONS: Chromoendoscopy with methylene blue appears to be an accurate, simple, safe, inexpensive, and reproducible method of detecting specialized columnar epithelium in Barrett's esophagus.     

Poor results of 5-aminolevulinic acid-photodynamic therapy for residual high-grade dysplasia and early cancer in barrett esophagus after endoscopic resection

BACKGROUND AND STUDY AIMS: The aim of the study was to evaluate the efficacy of photodynamic therapy (PDT) in the treatment of residual high-grade dysplasia or early cancer (HGD/EC) after endoscopic resection in Barrett esophagus. PATIENTS AND METHODS: Study patients were separated into group A, with proven residual HGD/EC, and group B with possible HGD/EC (positive lateral margins in the endoscopic resection specimen, without HGD/EC in the remaining Barrett esophagus). PDT treatment consisted of 5-aminolevulinic (5-ALA) photosensitization (40 mg/kg) followed by illumination of the Barrett esophagus with a total light dose of 100 J/cm (2). Complete remission was defined as the absence of HGD/EC in biopsies taken in two consecutive follow-up endoscopies. The percentage regression of Barrett esophagus, as well as the recurrence rate of HGD/EC, was calculated. RESULTS: 20 patients underwent PDT (group A, 11; group B, 9). Mild complications were seen in 4/26 procedures. The overall success rate was 15/20 (75 %). There was a significant difference in success rate between group A (55 %) and group B (100 %); P = 0.03. All patients had residual Barrett esophagus after PDT; the median regression percentage was 50 % (IQR 25 - 70 %). Recurrence of HGD/EC occurred in four patients (two each in groups A and B) after a median follow up of 30 months. CONCLUSIONS: In this selected group of patients, the addition of 5-ALA-PDT after endoscopic resection for HGD/EC had a disappointing success rate in patients who had residual HGD/EC after endoscopic resection. Most patients undergoing 5-ALA-PDT have residual Barrett mucosa after PDT and 5-ALA-PDT does not seem to prevent recurrences during follow-up.     

Value of chromoendoscopy and magnification endoscopy in the evaluation of duodenal abnormalities: a prospective,randomized comparison

BACKGROUND AND STUDY AIMS: Endoscopic staining methods are increasingly being used to evaluate lesions in the esophagus and colon. The aim of this prospective study was to investigate chromoendoscopy and magnification endoscopy for the evaluation of mucosal lesions in the duodenum. PATIENTS AND METHODS: Consecutive patients were randomly assigned to undergo conventional endoscopy without staining (group A) or intravital staining of the duodenal mucosa with indigo carmine and evaluation with a conventional video endoscope (group B) or a magnification endoscope (group C). Visible lesions were characterized before and after staining, and biopsies were taken for histological assessment. RESULTS: A total of 118 patients was examined. Chromoendoscopy detected significantly more lesions in the duodenal bulb (98 vs. 28; P = 0.0042) in more patients (29 vs. 15; P = 0.0025) compared with conventional endoscopy (group A). After mucosal staining, there was no difference between video endoscopy and magnification endoscopy with regard to the number or extent of the lesions identified. Significantly more targeted biopsies were possible after intravital staining. The most commonly identified lesions on targeted biopsies included (staining/control groups): gastric metaplasia (14/3), hyperplastic Brunner's glands (6/3), inflammatory changes (7/6), villous atrophy (1/3), adenoma (1/0). CONCLUSIONS: Intravital staining of the duodenum with indigo carmine may be useful for detecting mucosal abnormalities, delineating their extent, and allowing targeted biopsies. Magnification endoscopy, when used in addition to chromoendoscopy, does not appear to further increase the diagnostic yield for detecting duodenal abnormalities.     

Chromoendoscopic diagnosis of Barrett's esophagus

Some kinds of chromoendoscopy have been reported to survey the cases with Barrett's esophagus more effectively, since random biopsy as a gold standard is not an ideal method from the viewpoint of safety, labor or cost effectiveness. Methylene blue (MB) chromoendoscopy has been reported that a targeted biopsy is possible to limit because MB only stains non-dysplastic Barrett's mucosa but not dysplastic one. However, many of supplementary studies have not agreed this recommendation. Crystal violet (CV) chromoendoscopy clearly stains Barrett's mucosa and makes a detailed observation of pit pattern possible. The availability of this method is required a further mass survey although CV chromoendoscopy has been reported to be effective in Barrett's screening. Other chromoendoscopic methods using indigo carmine or fluorescence dye also have been reported to be effective for discovering a dysplastic lesion by some investigator, but the efficacy has not been sufficiently evidenced. Conclusively, chromoendoscopic diagnosis of Barrett's esophagus has not yet got a consensus in the availability for Barrett's surveillance at present in Barrett's Esophagus Chicago Workshop 2003 of AGA.     

窄带成像与放大染色技术在诊断胃癌及癌前病变中的对比研究

目的应用窄带成像技术（NBI）和放大染色技术对胃可疑病变处进行观察,比较两种技术在诊断胃癌及癌前病变中的差异。方法选取2008年10月至12月进行放大胃镜检查患者中胃小凹分型为Ⅲ型以上的40例患者作为研究对象,对可疑病变处依次进行放大胃镜、NBI放大胃镜和放大染色胃镜观察,对三者图像的清晰度、胃小凹分型评价情况以及胃癌和癌前病变诊断情况进行比较。结果在这40例患者中,NBI放大胃镜下观察病变清晰度明显高于放大胃镜下和放大染色胃镜下（P〈0．05）;NBI放大胃镜与放大染色胃镜在胃小凹分型的评价方面,差异无统计学意义（P〉0．05）;NBI放大胃镜对胃癌及癌前病变诊断的准确性、敏感性、特异性与放大染色胃镜比较,差异无统计学意义（P〉0．05）。结论NBI通过对胃小凹形态改变的观察,从而发现可疑病变,精确引导活检,有助于提高胃癌及癌前病变的检出率。     

Argon plasma coagulation in the treatment of Barrett's high-grade dysplasia and in situ adenocarcinoma

BACKGROUND AND STUDY AIMS: Endoscopic therapy of high-grade dysplasia (HGD) and superficial adenocarcinoma associated with Barrett's esophagus (BE), using Nd:YAG laser, KTP laser, or photodynamic therapy (PDT), has been reported to be effective in a curative role. Argon plasma coagulation (APC) appears to be effective in the eradication of nondysplastic Barrett's mucosa, but no results are available in the management of early neoplasms complicating BE. We report our initial experience in the application of APC in this indication. PATIENTS AND METHODS: Ten patients (mean age 74.2) with histologically proven HGD (n = 7) or in situ adenocarcinoma (n = 3) associated with BE (mean length 6 cm) and unfit for surgery were treated using APC and high-dose omeprazole (40 mg daily) until squamous re-epithelialization or complete eradication of the initially apparent lesions. Endoscopic follow-up was maintained at every 3 months. RESULTS: Complete eradication of HGD and in situ adenocarcinoma was achieved after a mean number of 3.3+/-1.5 APC sessions in 8/10 patients (80%). The eight patients with complete clearance of the neoplastic areas did not show any evidence of local recurrence during a median follow-up of 24 months (range 12-36 months). One patient with initial HGD had persistence of HGD 30 months after initial diagnosis, and one patient progressed to invasive adenocarcinoma after failure of APC and PDT. CONCLUSIONS: APC is safe and effective in the management of HGD and in situ adenocarcinoma associated with BE, and might represent an interesting alternative in selected patients who are not candidates for surgery.     

Endoscopic ultraviolet-induced autofluorescence spectroscopy of the esophagus: tissue characterization and potential for early cancer diagnosis

BACKGROUND AND STUDY AIMS: Endoscopic identification of dysplasia and early carcinoma of the esophagus is difficult and is currently done through random pinch biopsies. This study assesses the potential of ultraviolet-induced autofluorescence spectroscopy for early diagnosis with special focus on Barrett's esophagus. PATIENTS AND METHODS: Measurements were performed on 24 patients using 330 nm light excitation. The determination of the spectral distribution typical of each histological tissue type was done using three fluorescence intensity ratios: RI = I390nm/I450nm; R2 = I550nm/I450nm; R3 - I390nm/I550nm. RESULTS: The spectral distribution of normal esophageal mucosa and specialized columnar Barrett's mucosa were similar. A strong modification of the spectral distribution was observed for high grade dysplasia and intramucosal carcinoma. Statistical analysis indicated that the spectral shape modification associated with neoplastic transformation was greater than intra- and interpatient spectral variations. These results allow the determination of discriminating criteria based on ratios R1 and R3. Using ratio R3, the spectroscopy-based diagnosis differentiated neoplastic tissue from normal esophageal mucosa and specialized columnar Barrett's mucosa with a sensitivity and specificity of 86% and 95 %, respectively. CONCLUSIONS: The use of ultraviolet autofluorescence spectroscopy should improve the diagnostic yield of standard endoscopy in patients with Barrett's esophagus.     

Follow-up for high-grade dysplasia in Barrett's esophagus

This article will focus on the value of endoscopic follow-up for patients with high-grade dysplasia (HGD). Because the diagnosis of HGD in Barrett's esophagus is not a simple straightforward task, the article first will discuss the controversies regarding the histological diagnosis, followed by a discussion of the importance of endoscopic imaging for making the clinical diagnosis of HGD, and a systematic review of the literature relating to the presence of synchronous cancers in patients with HGD and the occurrence of cancer during endoscopic follow-up in these patients (metachronous cancers). Furthermore, the article will also discuss endoscopic techniques currently available for surveillance of these patients and make recommendations regarding surveillance intervals and the optimal biopsy protocol.     

醋酸染色联合窄带成像对胃黏膜肠上皮化生的诊断价值

目的:探讨内镜醋酸染色联合窄带成像模式对幽门螺杆菌阳性患者胃黏膜肠上皮化生(gastric intestinal metaplasia,GIM)病灶的诊断效果以及在筛查中的价值。方法:对93例幽门螺旋杆菌感染患者进行胃镜检查,分别在常规白光(esophagogastroduodenoscopy,EGD)、醋酸染色(acetic acid chromoendoscopy,ACC)、ACC联合窄带成像(narrow band imaging,NBI)3种模式下进行观察诊断并活检,比较3种模式下对GIM的诊断效果。结果:ACC+NBI模式的灵敏度为92.06%,远高于ACC模式的74.60%及EGD模式的30.16%,差别有统计学意义(P<0.05),3种模式的特异度差别无统计学意义(P>0.05)。EGD、ACC、ACC+NBI模式的ROC曲线AUC分别为0.584、0.790、0.860。结论:ACC联合NBI模式能明显提高内镜下胃黏膜GIM的诊断,是胃黏膜GIM筛查的良好工具。     

Methylene blue staining of dysplastic and nondysplastic Barrett's esophagus: an in vivo and ex vivo study

BACKGROUND AND STUDY AIMS: Methylene blue selectively stains specialized columnar epithelium in Barrett's esophagus with high accuracy. We prospectively evaluated the methylene blue staining properties of dysplastic and nondysplastic Barrett's esophagus and the association of these properties with the risk for dysplasia and cancer. PATIENTS AND METHODS: In a ex vivo study, we mapped, photographed, and sampled esophagectomy specimens with high grade dysplasia and/or early adenocarcinoma before and after methylene blue staining. In a concurrent in vivo study, we performed methylene blue staining and characterized methylene blue stain characteristics. Pathologists estimated the proportion of specialized columnar epithelium in each specimen and graded dysplasia. RESULTS: We examined 551 biopsies from 47 patients with biopsy-proven Barrett's esophagus and 48 sections from five surgical specimens with Barrett's esophagus and dysplasia and early adenocarcinoma. The accuracy of ex vivo and in vivo methylene blue staining for specialized columnar epithelium was 87% and 90%, respectively. It was influenced by the length of Barrett's esophagus, biopsy location, and the presence of esophagitis and/or dysplasia. Light to absent staining (p = 0.01) and moderate to marked heterogeneity (p = 0.01) were significantly associated with high grade dysplasia or cancer in the univariate analysis and in a multivariate model that adjusted for the length of Barrett's esophagus and the presence of a lesion. These staining characteristics were present in all patients with severe dysplasia and/or adenocarcinoma. CONCLUSIONS: Highly dysplastic or malignant Barrett's esophagus stains differently with methylene blue. Increased heterogeneity and decreased methylene blue stain intensity are significant independent predictors of high grade dysplasia and/or cancer. These features may help to direct biopsies in patients without a lesion.     

Barrett's adenocarcinoma

Esophageal adenocarcinoma has seen a rapid increase in incidence throughout the Western world. Gastroesophageal reflux disease is an important risk factor for this cancer that develops in patients with Barrett's esophagus, but infection with Helicobacter pylori may reduce the risk. The diagnosis of Barrett's adenocarcinoma is often at an advanced stage and is generally associated with a poor prognosis. Several innovative techniques (eg, chromoendoscopy, magnifying endoscopy, and narrow-band imaging) have recently been developed to improve the accuracy of diagnosis. Although surgical resection has been a mainstream treatment for advanced cancer, endoscopic submucosal dissection is becoming a promising treatment procedure for mucosal cancer. Surveillance, endoscopic ablative therapies, chemoprevention, and anti-reflux surgery have been developed for cancer prevention, but are of unproven value. Further evaluation is warranted to define the optimal method and standardize the procedures for diagnosis and management of Barrett's esophagus.     

Another look at Barrett's esophagus. Current thinking on screening and surveillance strategies

Barrett's esophagus remains a major health problem and a risk factor for the development of esophageal adenocarcinoma. Given the low incidence of this disorder, efforts should be made to identify risk factors that target patients with GERD or known Barrett's esophagus who would most benefit from screening and surveillance strategies. It is clear that identifying esophageal adenocarcinoma at an early and treatable stage reduces morbidity and mortality. However, currently available screening tools (endoscopy with surveillance biopsies every 2 years) are expensive and not easily applied. Identification of tumor markers and other specific risk factors may be helpful in predicting who is at risk for dysplasia. Current therapeutic strategies are successful in the treatment of GERD symptoms, but further research and longer follow-up studies are needed to determine if these strategies bring about regression of Barrett's esophagus, reversal of dysplasia, or prevention of cancer.     

自体荧光联合窄带成像技术对 Barrett 食管上皮内瘤变的诊断价值

目的：评价自体荧光（AFI）联合窄带成像（NBI）技术对 Barrett食管上皮内瘤变的诊断价值。方法对50例患者自体荧光内镜诊断Barrett的74个可疑上皮内瘤变的病灶,进一步行窄带成像检查,观察黏膜微血管及小凹的改变,并于相应病变区取活检送病理检查。结果在AFI诊断74例可疑病灶中共有44例病灶病理确诊为高级别上皮内瘤变（HGIN）,30例病灶为假阳性。NBI对这44例病灶HGIN的诊断：确诊39例,可疑5例;在30例HGIN假阳性的病灶中,NBI假阳性为7例。两者的假阳性率由40.5%减少至14.9%。自体荧光内镜对Barrett食管HGIN诊断的阳性预测值为59.5%（44/74）,AFI联合NBI技术后诊断的阳性预测值为84.8%（39/46）。结论自体荧光联合NBI技术可提高Barrett食管高级别上皮内瘤变的检出率。