Linked color imaging vs Lugol chromoendoscopy for esophageal squamous cell cancer and precancerous lesion screening: A noninferiority study

BACKGROUND Lugol chromoendoscopy(LCE)has served as a standard screening technique in high-risk patients with esophageal cancer.Nevertheless,LCE is not suitable for general population screening given its side effects.Linked color imaging(LCI)is a novel image-enhanced endoscopic technique that can distinguish subtle differences in mucosal color.AIM To compare the diagnostic performance of LCI with LCE in detecting esophageal squamous cell cancer and precancerous lesions and to evaluate whether LCE can be replaced by LCI in detecting esophageal neoplastic lesions.METHODS In this prospective study,we enrolled 543 patients who underwent white light imaging(WLI),LCI and LCE successively.We compared the sensitivity and specificity of LCI and LCE in the detection of esophageal neoplastic lesions.Clinicopathological features and color analysis of lesions were assessed.RESULTS In total,43 patients(45 neoplastic lesions)were analyzed.Among them,36 patients(38 neoplastic lesions)were diagnosed with LCI,and 39 patients(41 neoplastic lesions)were diagnosed with LCE.The sensitivity of LCI was similar to that of LCE(83.7%vs 90.7%,P=0.520),whereas the specificity of LCI was greater than that of LCE(92.4%vs 87.0%,P=0.007).The LCI procedure time in the esophageal examination was significantly shorter than that of LCE[42(34,50)s vs 160(130,189)s,P<0.001].The color difference between the lesion and surrounding mucosa in LCI was significantly greater than that observed with WLI.However,the color difference in LCI was similar in different pathological types of esophageal squamous cell cancer.CONCLUSION LCI offers greater specificity than LCE in the detection of esophageal squamous cell cancer and precancerous lesions,and LCI represents a promising screening strategy for general populations.

Validation of Fujinon intelligent chromoendoscopy with high definition endoscopes in colonoscopy

AIM:To validate high definition endoscopes with Fujinon intelligent chromoendoscopy(FICE) in colonoscopy.METHODS:The image quality of normal white light endoscopy(WLE),that of the 10 available FICE filters and that of a gold standard(0.2% indigo carmine dye) were compared.RESULTS:FICE-filter 4 [red,green,and blue(RGB) wavelengths of 520,500,and 405 nm,respectively] provided the best images for evaluating the vascular pattern compared to white light.The mucosal surface was best assessed using filter 4.However,the views obtained were not rated significantly better than those observed with white light.The "gold standard",indigo carmine(IC) dye,was found to be superior to both white light and filter 4.Filter 6(RGB wavelengths of 580,520,and 460 nm,respectively) allowed for exploration of the IC-stained mucosa.When assessing mucosal polyps,both FICE with magnification,and magnification following dye spraying were superior to the same techniques without magnification and to white light imaging.In the presence of suboptimal bowel preparation,observation with the FICE mode was possible,and endoscopists considered it to be superior to observation with white light.CONCLUSION:FICE-filter 4 with magnification improves the image quality of the colonic vascular patterns obtained with WLE.

Role of digital chromoendoscopy and confocal laser endomicroscopy for gastric intestinal metaplasia and cancer surveillance

In Japan and countries such as South Korea and Tai-wan, China, the standard technique for detecting earlygastric cancer (EGC) is chromoendoscopy. This technique involves a magnified endoscope and the use ofan indigo-carmine spray to distinguish between EGCand non-EGC areas. However, this technique is notwidely adopted in many parts of the world. One important reason for limited use is that this technique needsan experienced endoscopist to interpret the imagesduring the procedure. In addition, the sensitivity for detecting gastric intestinal metaplasia (GIM), a precancerous lesion of EGC, is graded as suboptimal. Moreover,the requirement of a cumbersome spraying method isinconvenient and needs preparation time. Easier digitalchromoendoscopy techniques, such as Narrow-bandImaging and Flexible spectral Imaging Color Enhancement, have been reported to facilitate targeted GIM and EGC biopsy. They provide higher sensitivities over conventional white light endoscopy. Recently, the noveltechnology of confocal laser endomicroscopy has been introduced as a high-magnification (1000 ×) real-time evaluation for many early gastrointestinal (GI) cancersand precancerous GI lesions, including colonic polyp,Barrett's esophagus, and GIM. The advantage of this technique is that it can be used as an in vivo confirmation of the presence of GIM and EGC during endoscopic surveillance. This review aims to explain the current information on the usefulness of digital chromoendos-copy and confocal laser endomicroscopy for evaluating GIM and EGC during endoscopic surveillance and the possible future role of these techniques for GI cancerscreening programs.

Magnified and enhanced computed virtual chromoendoscopy in gastric neoplasia: A feasibility study

AIM: To evaluate the feasibility of a new computed virtual chromoendoscopy (CVC) device (M i-scan) in the diagnosis of gastric neoplasia. METHODS: Patients with superficial lesions no larger than 1.0 cm found during high definition endoscopy were included. Those with advanced or obviously protruded or depressed lesions, lesions larger than 1.0 cm and/or lesions which were not amenable to observation by zoom function were excluded. The endoscopist was required to give the real-time descriptions of surface pit patterns of the lesions, based on surface pattern classification of enhanced magnification endoscopy. According to previous reports, types Ⅰ-Ⅲ represent nonneoplastic lesions, and types Ⅳ-Ⅴ represent neoplastic lesions. Diagnosis with M i-scan and biopsy was performed before histopathological diagnosis. Magnified images of gastric lesions with and without enhancement were collected for further analysis. The diagnostic yield of real-time M i-scan and effects on magnification image quality by tone enhancement (TE), surface enhancement (SE) and color enhancement (CE) were calculated. The selected images were sent to another endoscopist. The endoscopist rated the image quality of each lesion at 3 levels. Ratings of image quality were based on visualization of pit pattern, vessel and demarcation line. RESULTS: One hundred and eighty-three patients were recruited. Five patients were excluded for advanced gastric lesions, 1 patient was excluded for poor preparation and 2 patients were excluded for superficial lesions larger than 1.0 cm; 132 patients were excluded for no lesions found by high definition endoscopy. In the end, 43 patients with 43 lesions were included. Histopathology revealed 10 inflammation, 14 atrophy, 10 metaplasia, 1 low grade dysplasia (LGD), 5 high grade dysplasia (HGD) and 3 cancers. For 7 lesions classified into type Ⅰ, histopathology revealed 6 atrophy and 1 metaplasia; for 10 lesions classified into type Ⅱ, histopathology revealed 2 inflammation, 7 atrophy and 1 metaplasia; for 10 lesions classified into type Ⅲ, histopathology revealed 1 inflammation, 8 metaplasia and 1 LGD; for 9 lesions classified into type Ⅳ, histopathology revealed 4 inflammation, 1 atrophy and 4 HGD; for 7 lesions classified into type Ⅴ, histopathology revealed 3 inflammation, 1 HGD and 3 cancers. A total of 172 still images, including 43 images by white light (MWL) and 129 images by M i-scan (43 with TE, 43 with SE and 43 with CE), were selected and sent to the endoscopist who did the analysis. General image quality of M i-scan with TE and SE was significantly better than that of MWL (TE, 4.55 ± 1.07; SE, 4.30 ± 1.02; MWL, 3.25 ± 0.99; P < 0.001). Visualization of pit pattern was significantly improved by M i-scan with SE (1.93 ± 0.25 vs 1.50 ± 0.50, P < 0.001). Microvessel visualization was significantly improved by M i-scan with TE (1.23 ± 0.78 vs 0.76 ± 0.73, P < 0.001). Demarcation line visualization was improved by M i-scan with both TE and SE (TE, 1.75 ± 0.52; SE, 1.56 ± 0.59; MWL, 0.98 ± 0.44; P < 0.001). M i-scan with CE did not show any significant improvements of image quality in general or in the 3 key parameters. Although M i-scan with TE and SE slightly increased the diagnostic yield of MWL, there was no significant difference (P > 0.1). CONCLUSION: Although digital enhancement improves the image quality of magnification endoscopy, its value in improving the diagnostic yield seems to be limited.

Magnifying chromoendoscopy combined with immunohistochemical staining for early diagnosis of gastric cancer

AIM:To assess the diagnostic value of using magnifying chromoendoscopy combined with immunohisto-chemical staining of proliferating cell nuclear antigen (PCNA)and p53 in the detection of gastric precancerous lesions. METHODS:Ninety-five patients who were treated for abdominal discomfort,abdominal pain,bloating,and acid reflux at our hospital from January 2010 to December 2011 were included in the study.An ordinary gastroscopic procedure was initially performed to select the lesions.All subjects underwent magnifying chromo-endoscopy to observe morphological changes of gastric pits.Biopsies were then taken from each area of interest and sent for pathological examination and detection of PCNA and p53 expression by immunohistochemistry. An immunoreactivity score for each lesion was calcu-lated.Based on immunoreactivity scores,immunohisto-chemical staining was then considered. RESULTS:Compared to intestinal metaplasia,gastric pits were more diverse in size,more irregular in shape, and more disorderly in arrangement in moderate and severe dysplasia.PCNA and p53 expression was sig-nificantly higher in precancerous lesions(intestinal metaplasia and dysplasia)than in chronic gastritis. PCNA expression showed an upward trend in types A-F pits.The number of cases that showed strong PCNA positivity increased significantly with an increase in the severity of lesions.Rank sum test for independent samples showed that p53 expression was significantly higher in types E and F pits than in types A-D pits(H =33.068,P=0.000).Rank sum test for independent samples showed that PCNA expression was significantly higher in types E and F pits than in types A-D pits(H =31.791,P=0.001). CONCLUSION:The presence of types E and F pits,in which p53 and PCNA are highly expressed,is highly sug- gestive of the occurrence of early cancer,and patients developing these changes should be closely followed.

Real-life chromoendoscopy for dysplasia surveillance in ulcerative colitis

AIM To evaluate the use of chromoendoscopy for surveillance of ulcerative colitis in a real-life community hospital setting.METHODS Patients with extensive ulcerative colitis, having disease duration of more than 8 years and who presented between the years of 1999 to 2013, were offered enrolment in this single cohort prospective study. All participants underwent standard bowel preparation with sodium phosphate and chromoendoscopy. Two expert endoscopists, novice to chromoendoscopy, evaluated each segment of the colon with standarddefinition colonoscopes after spray application of 0.4% indigo carmine. All observed lesions were recorded and evaluated before being removed and/or biopsied. In addition, nontargeted biopsies were taken from each segment of the colon. The dysplasia detection rate and dysplasia detection yield were ascertained. RESULTS A total of 21 neoplastic lesions(2 carcinomas, 4 of high-grade dysplasia and 15 of low-grade dysplasia) and 27 nondysplastic lesions were detected in 16 of the total 67 patients(70% male; median disease duration: 17 years; median age at diagnosis: 25 years; 92% aminosalicylate-treated). The dysplasia detection rate was 10.5%(7/67 patients). The dysplasia detection yield was 20.8%(10/48) for targeted biopsies and 3.5%(11/318) for nontargeted biopsies. The sensitivity and specificity for the macroscopic evaluation of neoplasia using chromoendoscopy were 48% [95% confidence interval(CI): 26%-70%] and 96%(95%CI: 93%-98%), respectively. The positive predictive and negative predictive values were 42%(95%CI: 27%-59%) and 97%(95%CI: 95%-98%), respectively. A total of 19/21 dysplastic lesions were detected in mucosa with histologic inflammation.CONCLUSION Chromoendoscopy seems to be of value for dysplasia surveillance of ulcerative colitis in a community hospital setting. The yield of non-targeted biopsies is negligible.

Early colon cancer within a diverticulum treated by magnifying chromoendoscopy and laparoscopy

We report a unique case of intramucosal carcinoma in a tubulovillous adenoma arising from a single diverticulum.Endoscopic mucosal resection(EMR)was carried out successfully and completely with the assistance of laparoscopy.A 71-year-old man was admitted to our hospital because of melena and anemia.Emergent colonoscopy showed diverticulosis in the right-sided colon.However,endoscopy could not exactly detect the bleeding site.A flat elevated polyp was found within a single diverticulum located in the descending colon and diagnosed as an intramucosal carcinoma,as magnifying chromoendoscopy revealed a type Ⅳ pit pattern.As his diverticular bleeding repeated,a rightsided hemicolectomy was decided for treatment,the polyp within the diverticulum was also completely removed by EMR with the assistance of laparoscopy.Although a colonic perforation was detected immediately after EMR,the perforation was closed with endoclips intraluminally and also repaired laparoscopically from the serosal side.Histologically,the resected lesion was an intramucosal well-differentiated adenocarcinoma and the surgical margin was free of tumor.

Conventional colonoscopy and magnified chromoendoscopy for the endoscopic histological prediction of diminutive colorectal polyps: A single operator study

AIM： To accurately differentiate the adenomatous from the non-adenomatous polyps by colonoscopy. METHODS： All lesions detected by colonoscopy were first diagnosed using the conventional view followed by chromoendoscopy with magnification. The diagnosis at each step was recorded consecutively. All polyps were completely removed endoscopically for histological evaluation. The accuracy rate of each type of endoscopic diagnosis was evaluated, using histological findings as gold standard. RESULTS： A total of 240 lesions were identified, of which 158 （65.8%） were non-neoplastic and 82 （34.2%） were adenomatous. The overall diagnostic accuracy of conventional view, and chromoendoscopy with magnification was 76.3% （183/240） and 95.4% （229/240）, respectively （P〈 0.001） CONCLUSION： The combination of colonoscopy and magnified chromoendoscopy is the most reliable nonbiopsy method for distinguishing the non-neoplastic from the neoplastic lesions.

White light endoscopy,narrow band imaging and chromoendoscopy with magnification in diagnosing colorectal neoplasia

AIM:To evaluate the sensitivity(Sn),specificity(Sp),positive predictive value(PPV) and negative predictive value(NPV) of 3 different techniques:high resolution white light endoscopy(WLE),Narrow Band Imaging(NBI) and Chromoendoscopy(CHR),all with magnification in differentiating adenocarcinomas,adenomatous and hyperplastic colorectal polyps.METHODS:Each polyp was sequentially assessed first by WLE,followed by NBI and finally by CHR.Digital images of each polyp with each modality were taken and stored.Biopsies or polypectomies were then performed followed by blinded histopathological analysis.Each image was blindly graded based on the Kudo's pit pattern(KPP).In the assessment with NBI,the mesh brown capillary network pattern(MBCN) of each polyp was also described.The Sn,Sp,PPV and NPV of differentiating hyperplastic(Type Ⅰ & Ⅱ-KPP,Type Ⅰ-MBCN) adenomatous(Types Ⅲ,Ⅳ-KPP,Type Ⅱ-MBCN) and carcinomatous polyps(Type Ⅴ-KPP,Type Ⅲ-MCBN) was then compared with reference to the final histopathological diagnosis.RESULTS:A total of 50 colorectal polyps(5 adenocarcinomas,38 adenomas,7 hyperplastic) were assessed.CHR and NBI [KPP,MBCN or the combined classification(KPP & MBCN)] were superior to WLE in the prediction of polyp histology(P < 0.001,P=0.002,P=0.001 and P < 0.001,respectively).NBI,using the MBCN pattern or the combined classification showed higher numerical accuracies compared to CHR,but this was not statistically significant(P=0.625,0.250).CONCLUSION:This feasibility study demonstrated that this combined classification with NBI could potentially be useful in routine clinical practice,allowing the endoscopist to predict histology with higher accuracies using a less cumbersome and technically less challenging method.

Acetic acid chromoendoscopy: Improving neoplasia detection in Barrett's esophagus

Barrett&#x02019;s esophagus (BE) is an important condition given its significant premalignant potential and dismal five-year survival outcomes of advanced esophageal adenocarcinoma. It is therefore suggested that patients with a diagnosis of BE undergo regular surveillance in order to pick up dysplasia at an earlier stage to improve survival. Current &#x0201c;gold-standard&#x0201d; surveillance protocols suggest targeted biopsy of visible lesions followed by four quadrant random biopsies every 2 cm. However, this method of Barrett&#x02019;s surveillance is fraught with poor endoscopist compliance as the procedures are time consuming and poorly tolerated by patients. There are also significant miss-rates with this technique for the detection of neoplasia as only 13% of early neoplastic lesions appear as visible nodules. Despite improvements in endoscope resolution these problems persist. Chromoendoscopy is an extremely useful adjunct to enhance mucosal visualization and characterization of Barrett&#x02019;s mucosa. Acetic acid chromoendoscopy (AAC) is a simple, non-proprietary technique that can significantly improve neoplasia detection rates. This topic highlight summarizes the current evidence base behind AAC for the detection of neoplasia in BE and provides an insight into the direction of travel for further research in this area.

Colonic mucosa-associated lymphoid tissue lymphoma identified by chromoendoscopy

Colonic mucosa-associated lymphoid tissue (MALT) lymphomas are a rare occurrence and the definitive treatment has not been established. Solitary or multiple, elevated or polypoid lesions are the usual appearances of MALT lymphoma in the large intestine and sometimes the surface may reveal abnormal vascularity. Herein, we report a case of MALT lymphoma and review the relevant literature. Upon colonoscopy, a suspected pathologic lesion was observed in the proximal transverse colon. The lesion could be distinguished more prominently after using narrow-band imaging mode and indigo carmine-dye spraying chromoendoscopy. Histopathologic examination of this biopsy specimen revealed lymphoepithelial lesions with diffuse proliferation of atypical lymphoid cells effacing the glandular architecture and centrocyte-like cells infiltrating the lamina propria. Immunohistochemical analyses showed that tumor cells were positive for CD20 and Bcl-2e, and negative for CD10, CD23, and Bcl-6. According to Ann-Arbor staging system, the patient had stage IIE. A partial colectomy with dissection of the paracolic lymph nodes was performed. Until now, there is no recurrence of lymphoma at follow-up.

Role of digital chromoendoscopy in detecting minimal change esophageal reflux disease

Endoscopy is a widely used diagnostic tool to detect reflux esophagitis.Although its specificity was reported to be excellent at 90%-95%,its sensitivity was only 50%.Therefore,it is quite difficult to detect these lesions under the standard white light endoscopy especially in patients with minimal change esophageal reflux disease(MERD).In recent years,endoscopic technologies have evolved tremendously;these include high resolution and magnification digital chromoendoscopy.These technologies are useful practically for detecting various subtle lesions along the gastrointestinal tract starting from esophagus to colon.Currently,these technologies can be classified in 2 systems;pre-processed system(NBI,Olympus)and post processed system(FICE and i-SCAN,Fujinon and Pentax respectively).Over a few years,there have been many emerging publications on the benefit of these systems on MERD detection.The overall sensitivities to diagnose MERD were reported as much better than controls.However,large,multi-center and randomized controlled studies comparing these new imaging modalities with the conventional white light chromoendoscopy are warranted to validate its accuracy.Standard,simple and precise endoscopic reading criteria for the identification of MERD are also required.

Screening for colorectal cancer in patients with inflammatory bowel disease. Should we already perform chromoendoscopy in all our patients?

Patients with inflammatory bowel disease(commonly known as IBD) have a greater risk of colorectal cancer than the general population. Therefore, they are included in special programs for screening and followup. Chromoendoscopy, which has a high diagnostic yield in the detection of neoplasia, is generally the recommended endoscopy technique. However, this procedure does have some disadvantages(long examination time, need for optimal bowel preparation, specialist training), which increase its cost. How then can we overcome these barriers? First, it is necessary to educate hospital managers and directors of the advantages of chromoendoscopy in patients with IBD. Second, at least one endoscopist per center should be a specialist in the technique. Third, we should train nursing staff in the preparation of the dye. Finally, each examination should be given the time it needs. Even though clinical practice guidelines do not yet recommend the use of virtual imaging techniques such as narrow band imaging, a recent study reported no differences between the two approaches for the detection of tumors. Therefore, we believe that all patients should undergo chromoendoscopy. In the future, centers without access to dyes or where other barriers exist should at least perform narrow band imaging.

Detection of superficial esophageal squamous cell neoplasia by chromoendoscopy-guided confocal laser endomicroscopy

AIM: To evaluate the diagnostic potential of Lugol'schromoendoscopy-guided confocal laser endomicroscopy(CLE) in detecting superficial esophageal squamous cell neoplasia(ESCN).METHODS: Between December 2008 and September2010, a total of 52 patients were enrolled at the Chinese PLA General Hospital in Beijing, China. First,Lugol's chromoendoscopy-guided CLE was performed in these patients and the CLE in vivo histological diagnosis was recorded. Then, chromoendoscopyguided biopsy was performed in the same patients by another endoscopist who was blinded to the CLE findings. Based on the biopsy and CLE diagnosis, en bloc endoscopic resection was performed. The CLE in vivo diagnosis and the histological diagnosis of biopsy of ESCN were compared, using a histological examination of the endoscopic resection specimens as the standard reference.RESULTS: A total of 152 chromoendoscopy-guided biopsies were obtained from 56 lesions. In the 56 lesions of 52 patients, a total of 679 CLE images were obtained vs 152 corresponding biopsies. The sensitivity, specificity, negative predictive value and positive predictive value of chromoendoscopy-guided CLE compared with biopsy were 95.7% vs 82%(P <0.05), 90% vs 70%(P < 0.05), 81.8% vs 46.7%(P <0.05), and 97.8% vs 92.7%(P > 0.05), respectively.There was a significant improvement in sensitivity,specificity, negative predictive value, and accuracy when comparing chromoendoscopy-guided CLE with biopsy.CONCLUSION: Lugol's chromoendoscopy-guided CLE is a real-time, non-invasive endoscopic diagnostic technology; the accuracy of the detection of superficial ESCN is equivalent to or may be superior to biopsy histology.

Use and barriers to chromoendoscopy for dysplasia surveillance in inflammatory bowel disease

Traditionally,patients with inflammatory bowel disease(IBD) have been thought to be at increased risk of developing colitis-associated colorectal cancer.Although there are recent data suggesting that rates of colitisassociated cancer in IBD patients is declining,current guidelines still recommend regular dysplasia surveillance for early detection and prevention of neoplasia in patients with IBD.White-light endoscopy with random biopsies has been the traditional approach for dysplasia detection;however,newer technologies and approaches have emerged.One method,dye-based chromoendoscopy,has the potential to detect more dysplasia.However,longitudinal data to showing a benefit in morbidity or mortality from the use of chromoendoscopy are still lacking.Many societies have included recommendation on the use of chromoendoscopy with targeted biopsies as a method of surveillance for colitis-associated colorectal cancer.This narrative review seeks to outline data on dysplasia detection as well as barriers to the implementation of dye-based chromoendoscopy for the prevention and early detection of colitis-associated colorectal cancer.

Web-based system for training and dissemination of a magnification chromoendoscopy classification

AIM： To evaluate the use of web-based technologies to assess the learning curve and reassess reproducibility of a simplified version of a classification for gastric magnification chromoendoscopy （MC）. METHODS： As part of a multicenter trial, a hybrid approach was taken using a CD-ROM, with 20 films of MC lasting 5 s each and an ＂autorun＂ file triggering a local HTML frameset referenced to a remote questionnaire through an Internet connection. Three endoscopists were asked to prospectively and independently classify 10 of these films randomly selected with at least 3 d apart. The answers were centrally stored and returned to participants together with adequate feedback with the right answer. RESULTS： For classification in 3 groups, both intra- [Cohen＇s kappa （K） = 0.79-1.00 to 0.89-1.00] and inter-observer agreement increased from 1st （moderate） to 6th observation （k = 0.94）. Also, agreement with reference increased in the last observations （0.90, 1.00 and 1.00, for observers A, B and C, respectively）. Validity of 100% was obtained by all observers at their 4th observation. When a 4th （sub）group was considered, inter-observer agreement was almost perfect （K = 0.92） at 6th observation. The relation with reference clearly improved into K （0.93-1.00） and sensitivity （75%-100%） at their 6th observations. CONCLUSION： This MC classification seems to be easily explainable and learnable as shown by excellent intra- and inter-observer agreement, and improved agreement with reference. A web system such as the one used in this study may be useful for endoscopic or other image based diagnostic procedures with respect to definition, education and dissemination.

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.

Importance of the surrounding colonic mucosa in distinguishing between hyperplastic and adenomatous polyps during acetic acid chromoendoscopy

AIM: To examine the characteristics of colonic polyps, where it is difficult to distinguish adenomatous polyps from hyperplastic polyps, with the aid of acetic acid chromoendoscopy. METHODS: Acetic acid spray was applied to colonic polyps smaller than 10 mm before complete excision. Endoscopic images were taken before and 15-30 s after the acetic acid spray. Both pre-and post-sprayed images were shown to 16 examiners, who were asked to interpret the lesions as either hyperplastic or adenomatous polyps. Regression analysis was performed to determine which factors were most likely related to diagnostic accuracy. RESULTS: In 50 cases tested by the 16 examiners, the overall accuracy was 62.4% (499/800). Regression analysis demonstrated that surrounding colonic mucosa was the only factor that was significantly related to accuracy in discriminating adenomatous from hyperplastic polyps (P < 0.001). Accuracy was higher for polyps with linear surrounding colonic mucosa than for those with nodular surrounding colonic mucosa (P < 0.001), but was not related to the shape, location, or size of the polyp. CONCLUSION: The accuracy of predicting histology is significantly related to the pattern of colonic mucosa surrounding the polyp. Making a histological diagnosis of colon polyps merely by acetic acid spray is helpful for colon polyps with linear, regularly patterned surrounding colonic mucosa, and less so for those with nodular, irregularly patterned surrounding colonic mucosa.

Accuracy of virtual chromoendoscopy in differentiating gastric antral vascular ectasia from portal hypertensive gastropathy:A proof of concept study

BACKGROUND Accurate detection of gastric antral vascular ectasia(GAVE)is critical for proper management of cirrhosis-related gastrointestinal bleeding.However,endoscopic diagnosis of GAVE can be challenging when GAVE overlaps with severe portal hypertensive gastropathy(PHG).AIM To determine the added diagnostic value of virtual chromoendoscopy to high definition white light for real-time endoscopic diagnosis of GAVE and PHG.METHODS We developed an I-scan virtual chromoendoscopy criteria for diagnosis of GAVE and PHG.We tested our criteria in a cross-sectional cohort of cirrhotic adults with GAVE and PHG when high-definition white light endoscopy(HDWLE)diagnosis was in doubt.We then compared the accuracy of I-scan vs HDWLE alone to histology.RESULTS Twenty-three patients were included in this study(65.2%Caucasians and 60.9%males).Chronic hepatitis C was the predominant cause of cirrhosis(43.5%)and seven adults(30.4%)had confirmed GAVE on histology.I-scan had higher sensitivity(100%vs 85.7%)and specificity(75%vs 62.5%)in diagnosing GAVE compared to HDWLE.This translates into a higher,albeit not statistically significant,accuracy of I-scan in detecting GAVE compared to HDWLE alone(82%vs 70%).I-scan was less likely to lead to an accurate diagnosis of GAVE in patients on dialysis(P<0.05)and in patients with elevated creatinine(P<0.05).Iscan had similar accuracy to HDWLE in detecting PHG.CONCLUSION This pilot work supports that virtual chromoendoscopy may obviate the need for biopsies when the presence of GAVE is in doubt.Larger studies are needed to assess the impact of virtual chromoendoscopy on success of endoscopic therapy for GAVE.

Virtual chromoendoscopy in small bowel capsule endoscopy: New light or a cast of shadow?

AIM: To evaluate whether virtual chromoendoscopy can improve the delineation of small bowel lesions previously detected by conventional white light small bowel capsule endoscopy(SBCE). METHODS: Retrospective single center study. One hundred lesions selected from forty-nine consecutive conventional white light SBCE(SBCE-WL) examinations were included. Lesions were reviewed at three Flexible Spectral Imaging Color Enhancement(FICE) settings and Blue Filter(BF) by two gastroenterologists with ex-perience in SBCE, blinded to each other's findings, whoranked the quality of delineation as better, equivalent or worse than conventional SBCE-WL. Inter-observer percentage of agreement was determined and analyzed with Fleiss Kappa(k) coefficient. Lesions selected for the study included angioectasias(n = 39), ulcers/ero-sions(n = 49) and villous edema/atrophy(n = 12). RESULTS: Overall, the delineation of lesions was im-proved in 77% of cases with FICE 1, 74% with FICE 2, 41% with FICE 3 and 39% with the BF, with a percent-age of agreement between investigators of 89%(k = 0.833), 85%(k = 0.764), 66%(k = 0.486) and 79%(k = 0.593), respectively. FICE 1 improved the delineation of 97.4% of angioectasias, 63.3% of ulcers/erosions and 66.7% of villous edema/atrophy with a percentage of agreement of 97.4%(k = 0.910), 81.6%(k = 0.714) and 91.7%(k = 0.815), respectively. FICE 2 improved the delineation of 97.4% of angioectasias, 57.1% of ulcers/erosions and 66.7% of villous edema/atrophy, with a percentage of agreement of 89.7%(k = 0.802), 79,6%(k = 0.703) and 91.7%(k = 0.815), respectively. FICE 3 improved the delineation of 46.2% of angioecta-sias, 24.5% of ulcers/erosions and none of the cases of villous edema/atrophy, with a percentage of agreement of 53.8% [k = not available(NA)], 75.5%(k = NA) and 66.7%(k = 0.304), respectively. The BF improved the delineation of 15.4% of angioectasias, 61.2% of ulcers/erosions and 25% of villous edema/atrophy, with a per-centage of agreement of 76.9%(k = 0.558), 81.6%(k = 0.570) and 25.0%(k = NA), respectively.CONCLUSION: Virtual chromoendoscopy can improve the delineation of angioectasias, ulcers/erosions and villous edema/atrophy detected by SBCE, with almost perfect interobserver agreement for FICE 1.